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Linux Advantages:
1. Low cost: You don’t fancy to spend instant and cash to fashion licenses from the time of Linux and that much of its utility arrive provided the GNU General Public License. You can commence to administered straight off without being nervous this your service may prevent striving anytime while the free of charge trial version expires. Additionally, there are egregious repositories for that you can without restraint download prohibative valuable application for close to any goal you can suppose of.
2. Stability: Linux doesn’t would like to be rebooted periodically to sustain performance levels. It doesn’t freeze up or dwindle dropped in tiny bit due to memory leaks and such. Continuous up-times of hundreds of dollars of days (up to a year or more) are not uncommon.
3. Performance: Linux offers persistent above average performance on workstations and on networks. It can solve unusually significant concentrations of users simultaneously, and can take home old computers sufficiently responsive to be useful again.
4. Network friendliness: Linux was matured by a collection of programmers within the Internet and has therefore firm substantiation for network functionality; patron and server authorities can be just set up on any computer running Linux. It can perform tasks the as network backups more rapidly and a good amount responsibly as opposed to renewable systems.
5. Flexibility: Linux can be spent for insane performance server applications, desktop applications, and embedded systems. You can save disk space by sole installing the factors needed for a exact use. You can restrict the use of particular computers by installing for ideal one and only particular office applications rather of the total suite.
6. Compatibility: It works all routine Unix application products and can course all rampant file formats.
7. Choice: The enormous monkey of Linux distributions supplies you a choice. Each distribution is grown and supported by a unique organization. You can choose the one you covet best; the heart functionalities are the same; a large amount of utility works on the majority of distributions.
8. Fast and easy installation: Most Linux distributions appear among user-friendly installation and setup programs. Popular Linux distributions appear in on ideas which provide installation of a large amount of program particularly user friendly as well.
9. Full use of hard disk: Linux keeps operate vastly significantly when the hard disk is just about full.
10. Multitasking: Linux is programmed to do a multitude of conditions at the same time; e.g., a enormous printing job in the background won’t drop off lower your a good amount work.
11. Security: Linux is one of the multiple protected speaking systems. “Walls” and flexible file entrance concur institutions avert entrance by unwanted visitors or viruses. Linux users suffer to opportunity to some and safely download software, cost free of charge, based on information from online repositories containing thousands of insane worth packages. No condition sales requiring charge card concentrations or a greater amount of sensitive custom tips are necessary.
12. Open Source: If you raise service this requires knowledge or amendment of the speaking technique code, Linux’s source code is at your fingertips. Most Linux applications are Open Source as well.
Today the combination of cheap computers and cost free high-quality Linux speaking establishments and program issue out incredibly low-cost solutions for both simple structure office use and high-performance economy and science applications. The around opportunities of Linux distributions and Linux tool may be disasterous at first, but if you appreciate at which to look, it shouldn’t take extensively for you to realize superb online guidance.
Outsourcing SEO Tasks: The Benefits of Outsourcing SEO Tasks
The decision to outsource SEO job needs to be a closely judged to be one for a amount of reasons. The above all respect for a multitude of shoppers am able to be cost. On the whole, outsourcing SEO job can be significantly more inexpensive as opposed to carrying out the endeavor yourself ? outstandingly if you outsource abroad to India, Pakistan or the Philippines. It is levels bearing in mind, however, too rates is surely not the one and only happening to take to consideration.
Barriers in gobbledygook can often signal subjects in making an effort relationships. Misunderstanding briefs and specifications can lead drastic subjects and numerous cultures are apt to undergo strange approaches to industry and work. Ensuring too strict deadlines are met can be tricky ? outstandingly when one takes to consideration the unique tiny bit zones between the countries. It is fundamental the present you examination the trying culture of your calculated outsourcing commission before committing to any decision.
Efficiency and reliability is entirely essential to any struggling relationship involving outsourcing. After all, you are putting your sector and your reputation in this hands. A lack of contemplation to detail surrounded by SEO can explanation big subjects for websites and patrons and the team’s dedication to meeting deadlines and paying off treatment to detail must play a drastic portion in your decision to use them. If you’re not utterly comfortable, it may not be costs picking the risk.
The team’s SEO encounters is, of course, very much essential. When you’re quitting an vital SEO expect in the hands of others, you want to fashion assured properties knew how they’re doing. Write downhill a listing of sizeable SEO facets (PageRank, coming back link building, HTML optimization) and ask the council for this opinions on a cycle of concerns and too ask them to describe the methods. You as long as be fully comfortable amidst such a process and confident in such a knowledge and ability before deciding to use them.
On the whole, SEO outsourcing is a subject enormously price level pursuing. The tinier values and workload can be undoubtedly valuable to any industry striving to go on in the present arena climate. However, you have got to be guaranteed in the outsourcing team’s technical competency as greatly as this efficiency and reliability. Once you’re happy, proceed to try and strike a real estate deal providing the board that aide you both financially. The likely banana skins can be just avoided by after the advice in the current study and you serves to foresee too a struggling relationship in an SEO outsourcing council would be one of the most ideal details you frequently do.
Barriers in gobbledygook can often signal subjects in making an effort relationships. Misunderstanding briefs and specifications can lead drastic subjects and numerous cultures are apt to undergo strange approaches to industry and work. Ensuring too strict deadlines are met can be tricky ? outstandingly when one takes to consideration the unique tiny bit zones between the countries. It is fundamental the present you examination the trying culture of your calculated outsourcing commission before committing to any decision.
Efficiency and reliability is entirely essential to any struggling relationship involving outsourcing. After all, you are putting your sector and your reputation in this hands. A lack of contemplation to detail surrounded by SEO can explanation big subjects for websites and patrons and the team’s dedication to meeting deadlines and paying off treatment to detail must play a drastic portion in your decision to use them. If you’re not utterly comfortable, it may not be costs picking the risk.
The team’s SEO encounters is, of course, very much essential. When you’re quitting an vital SEO expect in the hands of others, you want to fashion assured properties knew how they’re doing. Write downhill a listing of sizeable SEO facets (PageRank, coming back link building, HTML optimization) and ask the council for this opinions on a cycle of concerns and too ask them to describe the methods. You as long as be fully comfortable amidst such a process and confident in such a knowledge and ability before deciding to use them.
On the whole, SEO outsourcing is a subject enormously price level pursuing. The tinier values and workload can be undoubtedly valuable to any industry striving to go on in the present arena climate. However, you have got to be guaranteed in the outsourcing team’s technical competency as greatly as this efficiency and reliability. Once you’re happy, proceed to try and strike a real estate deal providing the board that aide you both financially. The likely banana skins can be just avoided by after the advice in the current study and you serves to foresee too a struggling relationship in an SEO outsourcing council would be one of the most ideal details you frequently do.
Check Php web development with an accurate procedure of outsourcing
For developing any website mainly concern comes in mind in that blabber you can generate website simply and effectively? All the languages suffer this own aide and disadvantages. But the a good amount of suitable slang for every web tool is PHP. PHP web development is easy, quickly and exceptionally significantly rates effective. Now the matter arises how to select the suitable web development establishment when you rules to outsource your work. There is not anything covet top it is simply the professionalism the can attain the change in opting for a affirmatory PHP web development company. When presistently you searching online the beforehand concern arrive to mind this the seems of the website of any outsourcing company.
If you can not afford it a great deal additionally expert as opposed to you can not presume who your own website can be a great deal more qualified and attractive. I am not professing the present a excellent coming across as website can be top fit to your needs but initially skilled becoming website can draw the interest of a good number of visitors and which can turn in to customers. There are certain ingredients as if graphics in a website, content, navigation menu; SEO of the website can be checked as previous stage.
After the seems of the website you wish to preventing the substantiation for customer. What kind of consumer substantiation the firm supplies similar to Phone, Email and make a home support. Do properties undergo any dwell support, that can be aide broad when presistently any quandary occurs? Now a day’s dwell substantiation is basically important. Communication crisis can eliminate any presume so it is advisable to examine the communication skills of the expect head. If the predict leader not able to recognize the call of the program subsequently the development tedious work ought to not be successful.
One of the a multitude of substantial Times when outsource PHP Programming India is to scrutinize the portfolio of any web development company. Go for the duration of the portfolio of offshore IT firms how properties own wound up in past? Since how for a while properties are in the business? In how technologies properties are proficient? These circumstances can assistance to get smartest out of any web development organization before outsourcing any projects.
With all such Features Rightway Solution is one of the top opportunities when it comes to PHP web development. We hold acquired proficiency in PHP development in Flex, AIR that is the killer combination for any web software development. The professional and expert PHP developers hold produced various funny things winning projects that can be checked on the website of Rightway Solution. You can go throughout the portfolio and analyze the previous go of company.
Location of Web development organization is show a discrepency based on data from yours so get the awareness of development range of company. A remotely used up resource is basically intuitive or not can be checked before handing throughout the presume to any PHP web development company.
source:http://www.incplugins.com/php-web-development-with-an-accurate-procedure-of-outsourcing/
If you can not afford it a great deal additionally expert as opposed to you can not presume who your own website can be a great deal more qualified and attractive. I am not professing the present a excellent coming across as website can be top fit to your needs but initially skilled becoming website can draw the interest of a good number of visitors and which can turn in to customers. There are certain ingredients as if graphics in a website, content, navigation menu; SEO of the website can be checked as previous stage.
After the seems of the website you wish to preventing the substantiation for customer. What kind of consumer substantiation the firm supplies similar to Phone, Email and make a home support. Do properties undergo any dwell support, that can be aide broad when presistently any quandary occurs? Now a day’s dwell substantiation is basically important. Communication crisis can eliminate any presume so it is advisable to examine the communication skills of the expect head. If the predict leader not able to recognize the call of the program subsequently the development tedious work ought to not be successful.
One of the a multitude of substantial Times when outsource PHP Programming India is to scrutinize the portfolio of any web development company. Go for the duration of the portfolio of offshore IT firms how properties own wound up in past? Since how for a while properties are in the business? In how technologies properties are proficient? These circumstances can assistance to get smartest out of any web development organization before outsourcing any projects.
With all such Features Rightway Solution is one of the top opportunities when it comes to PHP web development. We hold acquired proficiency in PHP development in Flex, AIR that is the killer combination for any web software development. The professional and expert PHP developers hold produced various funny things winning projects that can be checked on the website of Rightway Solution. You can go throughout the portfolio and analyze the previous go of company.
Location of Web development organization is show a discrepency based on data from yours so get the awareness of development range of company. A remotely used up resource is basically intuitive or not can be checked before handing throughout the presume to any PHP web development company.
source:http://www.incplugins.com/php-web-development-with-an-accurate-procedure-of-outsourcing/
How to Make Website for Seo Friendly
11 Ways to Make Website SEO Friendly:
In the up to date Internet era at which billions of website are making surfed any day it is not adequate easily to own a website or writing a website investing in decently watch but it is in addition outstandingly significant to generate it reachable to the targeted visitors and post them through all the central components to transform them to would&wshyp;be customers.
Here get a couple of child's steps to attain your site a Search Engine Optimization friendly site:
1. Make it Simple:
Try to get your site as clear as you can. Make use of grey spaces on your site so this it visually too pleases visitors. Use appropriate font color in contrasting backgrounds. Less is more. It are able to boost to generate major ingredients a good deal more eye catching.
2. Avoid JavaScript:
Try to put off great use of JavaScript or any some scripting talk on your web page. Search Engine robots as per this algorithm do not was reading JavaScript codes and use of these types of codes goes up the mound bit of websites that annoys the user. As a result of that you may consume your prospective customer.
3. Avoid use of Frames and Flash:
Try to forestall high use of frames and flash as properties increase in value pile opportunity of the websites.
4. Organize Site:
Organize ones in a manner so too most every web site is only navigated based on information from all the webpages of the site. Navigation to the web sites serves to be easy and clear. The Anchor text provided be signficant to the link contained underneath.
5. Avoid Excessive use of Images:
Avoid use of unnecessary images on the website as properties increase in value the mountain opportunity of the website and create the website bulky. Do not overuse graphics on the web page.
6. Minimize Site Loading Time:
Site might be quick to mountain so the it can merely and swiftly get a message to your possibility visitors. Minimize the loading bit on your site as a good deal as you can.
7. Check Availability of Server:
The web server on that your website is hosted would be 24 X 7 up as searching engine robots can visit your website anytime. And unavailability of your site on making visited can cost you your impending visitor and hence you may cost your business.
8. Keep Navigation at the Left:
Create a Navigation tap and place the navigation links on the current section. Keep the navigation links to the fundamental webpages of your website on the left of the web web site as search engine engine robots primarily craft reading through your website based on the top left corner of the website and furthermore it is outstandingly still convenient for the web users also.
9. Relevant Content:
Don't forget overly visitors are cropping to your website to take specific information. And for giving the necessary hints to the visitors, search engine engines crawls your website. The final chief purpose is to post data to the visitors. So continue your website funny things informative and submit content on the website which is signficant to the site.
10. Manage Site Map:
Manage a site map containing the links of all the web sites of the website on a single web page so so a visitor can only get to the web page he wants to investing in the blessing of site map.
11. Avoid Scrolling:
Horizontal Scrolling!!!! Users use to despise horizontal scrolling on a web page. It have got to go now. Vertical Scrolling is OK if it is remarkably a good deal crucial to carry on it. But try to force your content or the tips on your web web site remarkably concise and snappy. Users could hold decently feel when properties appear to your site.
These are just now over&wshyp;arching facets too one is able to think about additonally designing a website or optimizing a website.
Search Engine Optimizing Companies too permits multiple web promotion services bid in event a good number of technical characteristics of causing a website SEO friendly as properties are slightly up to date of how searching engines are becoming for in a website.
In the up to date Internet era at which billions of website are making surfed any day it is not adequate easily to own a website or writing a website investing in decently watch but it is in addition outstandingly significant to generate it reachable to the targeted visitors and post them through all the central components to transform them to would&wshyp;be customers.
Here get a couple of child's steps to attain your site a Search Engine Optimization friendly site:
1. Make it Simple:
Try to get your site as clear as you can. Make use of grey spaces on your site so this it visually too pleases visitors. Use appropriate font color in contrasting backgrounds. Less is more. It are able to boost to generate major ingredients a good deal more eye catching.
2. Avoid JavaScript:
Try to put off great use of JavaScript or any some scripting talk on your web page. Search Engine robots as per this algorithm do not was reading JavaScript codes and use of these types of codes goes up the mound bit of websites that annoys the user. As a result of that you may consume your prospective customer.
3. Avoid use of Frames and Flash:
Try to forestall high use of frames and flash as properties increase in value pile opportunity of the websites.
4. Organize Site:
Organize ones in a manner so too most every web site is only navigated based on information from all the webpages of the site. Navigation to the web sites serves to be easy and clear. The Anchor text provided be signficant to the link contained underneath.
5. Avoid Excessive use of Images:
Avoid use of unnecessary images on the website as properties increase in value the mountain opportunity of the website and create the website bulky. Do not overuse graphics on the web page.
6. Minimize Site Loading Time:
Site might be quick to mountain so the it can merely and swiftly get a message to your possibility visitors. Minimize the loading bit on your site as a good deal as you can.
7. Check Availability of Server:
The web server on that your website is hosted would be 24 X 7 up as searching engine robots can visit your website anytime. And unavailability of your site on making visited can cost you your impending visitor and hence you may cost your business.
8. Keep Navigation at the Left:
Create a Navigation tap and place the navigation links on the current section. Keep the navigation links to the fundamental webpages of your website on the left of the web web site as search engine engine robots primarily craft reading through your website based on the top left corner of the website and furthermore it is outstandingly still convenient for the web users also.
9. Relevant Content:
Don't forget overly visitors are cropping to your website to take specific information. And for giving the necessary hints to the visitors, search engine engines crawls your website. The final chief purpose is to post data to the visitors. So continue your website funny things informative and submit content on the website which is signficant to the site.
10. Manage Site Map:
Manage a site map containing the links of all the web sites of the website on a single web page so so a visitor can only get to the web page he wants to investing in the blessing of site map.
11. Avoid Scrolling:
Horizontal Scrolling!!!! Users use to despise horizontal scrolling on a web page. It have got to go now. Vertical Scrolling is OK if it is remarkably a good deal crucial to carry on it. But try to force your content or the tips on your web web site remarkably concise and snappy. Users could hold decently feel when properties appear to your site.
These are just now over&wshyp;arching facets too one is able to think about additonally designing a website or optimizing a website.
Search Engine Optimizing Companies too permits multiple web promotion services bid in event a good number of technical characteristics of causing a website SEO friendly as properties are slightly up to date of how searching engines are becoming for in a website.
SQL Interview Questions with Answers: Top SQL Interview Questions
What is normalization? Explain unique proportions of normalization?
Check out the survey Q100139 based on Microsoft knowledge base and of
course, there is significantly !no! guidelines accessible in the net. It'll be a
good thinking to get a have of any RDBMS essentials text book,
especially the one by C. J. Date. Most of the times, it may be okay
if you can explain till third ordinary form.
What is denormalization and when is able to you go for it?
As the and cr indicates, denormalization is the contrary technique of
normalization. It's the controlled introduction of redundancy in to
the database design. It supports develop the query performance as the
number of joins serves to be reduced.
How do you embark on one-to-one, one-to-many and many-to-many
relationships additonally designing tables?
One-to-One relationship can be planned as a single table and
rarely as two tables amongst main and international key relationships.
One-to-Many relationships are intended by splitting the information into
two tables amidst chief key and intercontinental key relationships.
Many-to-Many relationships are designed making use of a junction table with
the keys based on what i read in both the tables forming the composite main key of the
junction table.
It plans to be a desired notion to was reading up a database designing fundamentals
text book.
What's the change between a chief key and a distinct key?
Both number one key and distinct enforce uniqueness of the column on which
they are defined. But by default chief key creates a clustered index
on the column, at which are unusual creates a nonclustered index by
default. Another monumental change is that, number one key does not allow
NULLs, but valuable key offers one NULL only.
What are user defined datatypes and when you might go for them?
User defined datatypes let you give the base SQL Server datatypes by
providing a descriptive name, and format to the database. Take for
example, in your database, there is a column labeled Flight_Num which
appears in different tables. In all such tables it serves to be varchar(8).
In such a state of affairs you were able to implement a user defined datatype called
Flight_num_type of varchar(8) and use it everywhere all your tables.
See sp_addtype, sp_droptype in books online.
What is bit datatype and what is the hints overly can be stored
inside a bit column?
Bit datatype is spent to list boolean data similar to 1 or 0 (true or
false). Untill SQL Server 6.5 bit datatype are able to own either a 1 or 0
and there was no validation for NULL. But from what i read in SQL Server 7.0 onwards,
bit datatype can speak for a third state, that is NULL.
Define candidate key, alternate key, composite key.
A candidate key is one overly can identify every row of a table uniquely.
Generally a candidate key gets the number one key of the table. If the
table has other as opposed to one candidate key, one of them is able to become the
primary key, and the rest are identified alternate keys.
A key made by combining at the very least two or a multitude of columns is called
composite key.
What are defaults? Is there a column to that a default won't be bound?
A default is a expense the present will be able to be used up by a column, if no price level is
supplied to too column additonally putting in data. IDENTITY columns and
timestamp columns won't suffer loan failures bound to them. See CREATE
DEFUALT in books online.
Back to top
SQL Server architecture (top)
What is a condition and how are ACID properties?
A sell is a levelheaded unit of grunt work in which, all the steps must
be performed or none. ACID stands for Atomicity, Consistency,
Isolation, Durability. These are the residences of a transaction. For
more guidelines and trigger of such properties, see SQL Server
books online or any RDBMS basics text book.
Explain many isolation levels
An isolation total sum determines the degree of isolation of info between
concurrent transactions. The default SQL Server isolation quantity is
Read Committed. Here are the a larger number of isolation prices (in the ascending
order of isolation): Read Uncommitted, Read Committed, Repeatable
Read, Serializable. See SQL Server books online for an motive of
the isolation levels. Be definite to saw approximately SET TRANSACTION ISOLATION
LEVEL, that lets you customize the isolation rate at the connection
level.
CREATE INDEX myIndex ON myTable(myColumn)
What sort of Index am able to get came up with ensuing executing the above statement?
Non-clustered index. Important happening to note: By default a clustered
index becomes came up with on the number one key, unless specified otherwise.
What's the maximum size of a row?
8060 bytes. Don't be surprised in on topics as if 'what is the
maximum total sum of columns per table'. Check out SQL Server books
online for the web site titled: "Maximum Capacity Specifications".
Explain Active/Active and Active/Passive assembly configurations
Hopefully you experience have setting up collection servers. But if you
don't, at minimum be familiar in the way clustering functions and the two
clusterning configurations Active/Active and Active/Passive. SQL
Server books online has an adequate amount of info on their topic and there is
a the best grey paper on hand on Microsoft site.
Explain the architecture of SQL Server
This is a truly pertinent issue and you higher be able to solution it
if ponder yourself a DBA. SQL Server books online is the most ideal place
to read over throughout SQL Server architecture. Read up the chapter dedicated
to SQL Server Architecture.
What is lock escalation?
Lock escalation is the technique of converting a lot of low total amount locks
(like row locks, web page locks) to better grade locks (like table
locks). Every lock is a memory house too most locks is able to mean,
more memory making populated by locks. To hold off their based on what i read in happening,
SQL Server escalates the a large number of fine-grain locks to a lower amount of coarse-grain
locks. Lock escalation threshold was definable in SQL Server 6.5, but
from SQL Server 7.0 onwards it is dynamically strive by SQL Server.
What's the change between DELETE TABLE and TRUNCATE TABLE commands?
DELETE TABLE is a logged operation, so the deletion of every row gets
logged in the purchase log, that affects it slow. TRUNCATE TABLE
also deletes all the rows in a table, but it will not log the deletion of
each row, rather it logs the deallocation of the information web sites of the
table, that causes it faster. Of course, TRUNCATE TABLE can be rolled
back.
Explain the storage examples of OLAP
Check out MOLAP, ROLAP and HOLAP in SQL Server books online for more
infomation.
What are the new parts introduced in SQL Server 2000 (or the latest
release of SQL Server at the while of your interview)? What changed
between the first version of SQL Server and the contemporary version?
This measure is usually surveyed to see how up to date is your knowledge.
Generally there is a section in the begun of the books online
titled "What's New", that has all this type of information. Of course,
reading just now who is not enough, you may experience tried people conditions to
better solution the questions. Also assess out the section titled
"Backward Compatibility" in books online that talks close to the changes
that undergo taken place in the new version.
What are constraints? Explain several sorts of constraints.
Constraints enable the RDBMS enforce the integrity of the database
automatically, without needing you to form triggers, fundamental or defaults.
Types of constraints: NOT NULL, CHECK, UNIQUE, PRIMARY KEY, FOREIGN KEY
For an rationale of these types of constraints see books online for the pages
titled: "Constraints" and "CREATE TABLE", "ALTER TABLE"
Whar is an index? What are the sorts of indexes? How multiple clustered
indexes can be made on a table? I construct a separate index on each
column of a table. how are the benefits and disadvantages of this
approach?
Indexes in SQL Server are similar to the indexes in books. They help
SQL Server retrieve the info quicker.
Indexes are of two types. Clustered indexes and non-clustered indexes.
When you craete a clustered index on a table, all the rows in the
table are stored in the shape of the clustered index key. So, there
can be just one clustered index per table. Non-clustered indexes have
their own storage separate based on data from the table info storage. Non-clustered
indexes are stored as B-tree homes (so do clustered indexes),
with the leaf grade nodes in posession of the index key and it is row locater.
The row located can be the RID or the Clustered index key, depending
up on the absence or occurrence of clustered index on the table.
If you initiate an index on every column of a table, it improves the
query performance, as the query optimizer can decide on based on information from all the
existing indexes to arrive up providing an small execution plan. At the
same t ime, info revision operations (such as INSERT, UPDATE,
DELETE) might become slow, as each age info fluxes in the table, all
the indexes fancy to be updated. Another disadvantage is that, indexes
need disk space, the !no! indexes you have, other disk space is used.
Back to top
Database administration (top)
What is RAID and how are unusual sorts of RAID configurations?
RAID stands for Redundant Array of Inexpensive Disks, used up to provide
fault tolerance to database servers. There are six RAID numbers 0
through 5 submiting strange value of performance, fault tolerance.
MSDN has a good deal of data right about RAID values and for detailed
information, examine out the RAID advisory board's homepage
What are the steps you serves to take to boost performance of a poor
performing query?
This is a essentially open concluded ask and there could easily be a lot of reasons
behind the faulty performance of a query. But selected whole difficulties that
you are able to jargon roughly ought to be: No indexes, table scans, missing or out
of date statistics, blocking, excess recompilations of stored
procedures, rules and triggers without SET NOCOUNT ON, poorly
written query amidst unnecessarily complicated joins, too much
normalization, excess usage of cursors and temporary tables.
Some of the tools/ways this assistance you troubleshooting performance
problems are: SET SHOWPLAN_ALL ON, SET SHOWPLAN_TEXT ON, SET
STATISTICS IO ON, SQL Server Profiler, Windows NT /2000 Performance
monitor, Graphical execution initiative in Query Analyzer.
Download the grey paper on performance tuning SQL Server from
Microsoft web site. Don't forget to evaluate out sql-server-performance.com
What are the steps you would take, if you are tasked among securing an
SQL Server?
Again now is one more open finished question. Here are Other details you
could lingo about: Preferring NT authentication, making the most of server, databse
and software roles to control entrance to the data, securing the
physical database files employing NTFS permissions, making use of an unguessable
SA password, restricting physical entrance to the SQL Server, renaming
the Administrator consideration on the SQL Server computer, disabling the
Guest account, enabling auditing, paying off multiprotocol encryption,
setting up SSL, setting up firewalls, isolating SQL Server for the
web server etc.
Read the grey paper on SQL Server security according to Microsoft website.
Also inspect out My SQL Server security proper practices
What is a deadlock and how is a reside lock? How am able to you go about
resolving deadlocks?
Deadlock is a circumstances when two processes, every invested in a lock on one
piece of data, try to obtain a lock on the other's piece. Each
process may wait eternally for the opposite to release the lock,
unless one of the user manages is terminated. SQL Server detects
deadlocks and terminates one user's process.
A livelock is one, at which a ask for for an exclusive lock is
repeatedly denied while a string of overlapping shared locks keeps
interfering. SQL Server detects the condition once two denials and
refuses a large amount of shared locks. A livelock furthermore takes place when read
transactions monopolize a table or page, forcing a come up with transaction
to wait indefinitely.
Check out SET DEADLOCK_PRIORITY and "Minimizing Deadlocks" in SQL
Server books online. Also look over out the content Q169960 based on information from Microsoft
knowledge base.
What is blocking and how ought to you troubleshoot it?
Blocking takes place when one connection for an software holds a lock
and a instant connection requires a conflicting lock type. This forces
the minute connection to wait, blocked on the first.
Read up the next concerns in SQL Server books online: Understanding
and averting blocking, Coding tiny transactions.
Explain CREATE DATABASE syntax
Many of us are spent to craeting databases from what i read in the Enterprise Manager
or by just now furnishing the command: CREATE DATABAE MyDB. But how if you
have to build a database amid two filegroups, one on impel C and the
other on force D through log on urge E amid an previous size of 600 MB
and provided a increment cog of 15%? That's why making a DBA you as long as be
familiar through the CREATE DATABASE syntax. Check out SQL Server books
online for more and more information.
How to restart SQL Server in single user mode? How to initiate SQL Server
in tiny configuration mode?
SQL Server can be began on command line, making use of the SQLSERVR.EXE.
This EXE has a couple of particularly monumental parameters in that a DBA will be
familiar with. -m is depleted for appearing SQL Server in single user mode
and -f is spent to initiate the SQL Server in pithy confuguration mode.
Check out SQL Server books online for !no! parameters and their
explanations.
As a half of your job, how are the DBCC commands such a you commonly
use for database maintenance?
DBCC CHECKDB, DBCC CHECKTABLE, DBCC CHECKCATALOG, DBCC CHECKALLOC,
DBCC SHOWCONTIG, DBCC SHRINKDATABASE, DBCC SHRINKFILE etc. But there
are a entire mountain of DBCC commands that are essentially useful for DBAs.
Check out SQL Server books online for a larger number of information.
What are statistics, underneath how shape properties go out of date, how
do you update them?
Statistics determine the selectivity of the indexes. If an indexed
column has top notch cost levels next the selectivity of such a index is more,
as opposed to an index providing non-unique values. Query optimizer uses
these indexes in determining whether to decide on an index or not while
executing a query.
Some circumstances below that you must update statistics:
1) If there is major tweak in the key market values in the index
2) If a considerable quantity of information in an indexed column has been heard added,
changed, or removed (that is, if the distribution of key price has
changed), or the table has continued truncated making use of the TRUNCATE TABLE
statement and at that time repopulated
3) Database is upgraded from what i read in a earliest version
Look up SQL Server books online for the coming commands: UPDATE
STATISTICS, STATS_DATE, DBCC SHOW_STATISTICS, CREATE STATISTICS, DROP
STATISTICS, sp_autostats, sp_createstats, sp_updatestats
What are the multitude of ways of moving data/databases between servers
and databases in SQL Server?
There are oodles of opportunities available, you own to decide your option
depending upon your requirements. Some of the opportunities you hold are:
BACKUP/RESTORE, dettaching and attaching databases, replication, DTS,
BCP, logshipping, INSERT...SELECT, SELECT...INTO, generating INSERT
scripts to make data.
Explian weird sorts of BACKUPs avaialabe in SQL Server? Given a
particular scenario, how can you go something like opting for a backup plan?
Types of backups you can initiate in SQL Sever 7.0+ are Full database
backup, differential database backup, arrangement log backup,
filegroup backup. Check out the BACKUP and RESTORE commands in SQL
Server books online. Be willing to spit out the commands in your
interview. Books online additionally has data on detailed
backup/restore architecture and when one providing go for a particular
kind of backup.
What is database replicaion? What are the diverse sorts of
replication you can set up in SQL Server?
Replication is the technique of copying/moving info between databases on
the same or multiple servers. SQL Server emphasizes the next types
of replication scenarios:
* Snapshot replication
* Transactional replication (with immediate updating subscribers,
with queued updating subscribers)
* Merge replication
See SQL Server books online for indepth indemnity on replication. Be
prepared to explain how strange replication realtors function, what
are the number one process tables expended in replication etc.
How to determine the benefits pack by now installed on SQL Server?
The intercontinental variable @@Version stores the fashion total number of the
sqlservr.exe, that is exhausted to determine the treatment pack installed.
To appreciated further in regards to that procedure visit SQL Server assistance packs and
versions.
Back to top
Database programming (top)
What are cursors? Explain several sorts of cursors. What are the
disadvantages of cursors? How can you prevent cursors?
Cursors let row-by-row prcessing of the resultsets.
Types of cursors: Static, Dynamic, Forward-only, Keyset-driven. See
books online for supplementary information.
Disadvantages of cursors: Each cycle you fetch a row of the cursor,
it possible results in a network roundtrip, at which as a conventional SELECT query
makes just one rowundtrip, but then larger the resultset is. Cursors are
also steep when properties motivate larger amount of equipment and temporary storage
(results in a good amount IO operations). Furthere, there are restrictions on
the SELECT statements which can be expended in on a little sorts of cursors.
Most of the times, set rooted operations can be expended rather of
cursors. Here is an example:
If you experience to offer a flat hike to your workforces paying off the following
criteria:
Salary between 30000 and 40000 -- 5000 hike
Salary between 40000 and 55000 -- 7000 hike
Salary between 55000 and 65000 -- 9000 hike
In that state a good number of developers have a propensity to use a cursor, determine each
employee's salary and update his salary according to the above
formula. But the same can be reached by numerous update statements or
can be combined in a single UPDATE statement as substantiated below:
UPDATE tbl_emp SET salary =
CASE WHEN salary BETWEEN 30000 AND 40000 THEN salary + 5000
WHEN salary BETWEEN 40000 AND 55000 THEN salary + 7000
WHEN salary BETWEEN 55000 AND 65000 THEN salary + 10000
END
Another problem in that developers have a tendency to use cursors: You seek to
call a stored process when a column in a individual row meets
certain condition. You do not experience to use cursors for this. This can be
achieved making the most of WHILE loop, as extensively as there is a different key to
identify every row. For tendencies of paying WHILE loop for row by row
processing, take a look at out the 'My code library' section of my site or
search for WHILE.
Write decreased the overall syntax for a SELECT statements covering all the
options.
Here's the easy syntax: (Also checkout SELECT in books online for
advanced syntax).
SELECT select_list
[INTO new_table_]
FROM table_source
[WHERE search_condition]
[GROUP BY group_by__expression]
[HAVING search_condition]
[ORDER BY order__expression [ASC | DESC] ]
What is a join and explain unusual kinds of joins.
Joins are used up in problems to explain how strange tables are related.
Joins moreover let you specific info of a table depending upon information from
another table.
Types of joins: INNER JOINs, OUTER JOINs, CROSS JOINs. OUTER JOINs are
further classified as LEFT OUTER JOINS, RIGHT OUTER JOINS and FULL
OUTER JOINS.
For a great deal more tips see web sites based on data from books online titled: "Join
Fundamentals" and "Using Joins".
Can you undergo a nested transaction?
Yes, really much. Check out BEGIN TRAN, COMMIT, ROLLBACK, SAVE TRAN and
@@TRANCOUNT
What is an long stored procedure? Can you instantiate a COM object
by paying for T-SQL?
An long stored course is a function during a DLL (written in a
programming terminology as C, C++ paying for Open Data Services (ODS) API)
that can be referred to as based on information from T-SQL, simply the way we employ standard stored
procedures paying for the EXEC statement. See books online to decide how to
create long stored rules and how to add them to SQL Server.
Yes, you can instantiate a COM (written in languages want VB, VC++)
object based on what i read in T-SQL by employing sp_OACreate stored procedure. Also see
books online for sp_OAMethod, sp_OAGetProperty, sp_OASetProperty,
sp_OADestroy. For an model of producing a COM object in VB and
calling it from what i read in T-SQL, see 'My code library' section of currently site.
What is the method function to get the the most recent user's user id?
USER_ID(). Also assess out a greater number of method runs want USER_NAME(),
SYSTEM_USER, SESSION_USER, CURRENT_USER, USER, SUSER_SID(), HOST_NAME().
What are triggers? How multi triggers you can experience on a table? How to
invoke a rationale on demand?
Triggers are special type of stored plan overly get executed
automatically when an INSERT, UPDATE or DELETE utilization takes place
on a table.
In SQL Server 6.5 you serves to define merely 3 triggers per table, one for
INSERT, one for UPDATE and one for DELETE. From SQL Server 7.0
onwards, the present restriction is gone, and you might compose multiple
triggers per every action. But in 7.0 there is no way to control the
order in that the triggers fire. In SQL Server 2000 you am able to specify
which instigate fires first and foremost or fires go on making use of sp_settriggerorder
Triggers can not be invoked on demand. They get triggered easily when an
associated action (INSERT, UPDATE, DELETE) takes place on the table on
which properties are defined.
Triggers are normally used up to craft market rules, auditing.
Triggers can too be spent to give the referential integrity checks,
but wherever possible, use constraints for presently purpose, alternatively of
triggers, as constraints are still faster.
Till SQL Server 7.0, triggers fire one and only in the wake of the info modification
operation happens. So in a way, properties are identified give triggers. But in
SQL Server 2000 you would engender pre triggers also. Search SQL Server
2000 books online for INSTEAD OF triggers.
Also assess out books online for 'inserted table', 'deleted table' and
COLUMNS_UPDATED()
There is a lead to defined for INSERT operations on a table, in an
OLTP system. The reason is written to instantiate a COM object and
pass the newly insterted rows to it for select individualized processing. What
do you agree of this moment implementation? Can the be calculated better?
Instantiating COM objects is a second consuming technique and as of you
are working at it based on what i read in within the duration of a trigger, it slows low the info insertion
process. Same is the circumstances providing sending emails based on triggers. This
scenario can be higher designed by logging all the pertinent data
into a separate table, and hold a job that periodically checks this
table and performs the needful.
What is a self join? Explain it in on an example.
Self join is only such as any more and more join, apart from such a two instances of
the same table can be joined in the query. Here is an example:
Employees table that contains rows for standard workforces as far as
managers. So, to submit out the managers of all the employees, you need
a self join.
CREATE TABLE emp
(
empid int,
mgrid int,
empname char(10)
)
INSERT emp SELECT 1,2,'Vyas'
INSERT emp SELECT 2,3,'Mohan'
INSERT emp SELECT 3,NULL,'Shobha'
INSERT emp SELECT 4,2,'Shridhar'
INSERT emp SELECT 5,2,'Sourabh'
SELECT t1.empname [Employee], t2.empname [Manager]
FROM emp t1, emp t2
WHERE t1.mgrid = t2.empid
Here's an advanced query paying off a LEFT OUTER JOIN the current a good deal takings the
employees without managers (super bosses)
SELECT t1.empname [Employee], COALESCE(t2.empname, 'No manager') [Manager]
FROM emp t1
LEFT OUTER JOIN
emp t2
ON
t1.mgrid = t2.empid
Check out the survey Q100139 based on Microsoft knowledge base and of
course, there is significantly !no! guidelines accessible in the net. It'll be a
good thinking to get a have of any RDBMS essentials text book,
especially the one by C. J. Date. Most of the times, it may be okay
if you can explain till third ordinary form.
What is denormalization and when is able to you go for it?
As the and cr indicates, denormalization is the contrary technique of
normalization. It's the controlled introduction of redundancy in to
the database design. It supports develop the query performance as the
number of joins serves to be reduced.
How do you embark on one-to-one, one-to-many and many-to-many
relationships additonally designing tables?
One-to-One relationship can be planned as a single table and
rarely as two tables amongst main and international key relationships.
One-to-Many relationships are intended by splitting the information into
two tables amidst chief key and intercontinental key relationships.
Many-to-Many relationships are designed making use of a junction table with
the keys based on what i read in both the tables forming the composite main key of the
junction table.
It plans to be a desired notion to was reading up a database designing fundamentals
text book.
What's the change between a chief key and a distinct key?
Both number one key and distinct enforce uniqueness of the column on which
they are defined. But by default chief key creates a clustered index
on the column, at which are unusual creates a nonclustered index by
default. Another monumental change is that, number one key does not allow
NULLs, but valuable key offers one NULL only.
What are user defined datatypes and when you might go for them?
User defined datatypes let you give the base SQL Server datatypes by
providing a descriptive name, and format to the database. Take for
example, in your database, there is a column labeled Flight_Num which
appears in different tables. In all such tables it serves to be varchar(8).
In such a state of affairs you were able to implement a user defined datatype called
Flight_num_type of varchar(8) and use it everywhere all your tables.
See sp_addtype, sp_droptype in books online.
What is bit datatype and what is the hints overly can be stored
inside a bit column?
Bit datatype is spent to list boolean data similar to 1 or 0 (true or
false). Untill SQL Server 6.5 bit datatype are able to own either a 1 or 0
and there was no validation for NULL. But from what i read in SQL Server 7.0 onwards,
bit datatype can speak for a third state, that is NULL.
Define candidate key, alternate key, composite key.
A candidate key is one overly can identify every row of a table uniquely.
Generally a candidate key gets the number one key of the table. If the
table has other as opposed to one candidate key, one of them is able to become the
primary key, and the rest are identified alternate keys.
A key made by combining at the very least two or a multitude of columns is called
composite key.
What are defaults? Is there a column to that a default won't be bound?
A default is a expense the present will be able to be used up by a column, if no price level is
supplied to too column additonally putting in data. IDENTITY columns and
timestamp columns won't suffer loan failures bound to them. See CREATE
DEFUALT in books online.
Back to top
SQL Server architecture (top)
What is a condition and how are ACID properties?
A sell is a levelheaded unit of grunt work in which, all the steps must
be performed or none. ACID stands for Atomicity, Consistency,
Isolation, Durability. These are the residences of a transaction. For
more guidelines and trigger of such properties, see SQL Server
books online or any RDBMS basics text book.
Explain many isolation levels
An isolation total sum determines the degree of isolation of info between
concurrent transactions. The default SQL Server isolation quantity is
Read Committed. Here are the a larger number of isolation prices (in the ascending
order of isolation): Read Uncommitted, Read Committed, Repeatable
Read, Serializable. See SQL Server books online for an motive of
the isolation levels. Be definite to saw approximately SET TRANSACTION ISOLATION
LEVEL, that lets you customize the isolation rate at the connection
level.
CREATE INDEX myIndex ON myTable(myColumn)
What sort of Index am able to get came up with ensuing executing the above statement?
Non-clustered index. Important happening to note: By default a clustered
index becomes came up with on the number one key, unless specified otherwise.
What's the maximum size of a row?
8060 bytes. Don't be surprised in on topics as if 'what is the
maximum total sum of columns per table'. Check out SQL Server books
online for the web site titled: "Maximum Capacity Specifications".
Explain Active/Active and Active/Passive assembly configurations
Hopefully you experience have setting up collection servers. But if you
don't, at minimum be familiar in the way clustering functions and the two
clusterning configurations Active/Active and Active/Passive. SQL
Server books online has an adequate amount of info on their topic and there is
a the best grey paper on hand on Microsoft site.
Explain the architecture of SQL Server
This is a truly pertinent issue and you higher be able to solution it
if ponder yourself a DBA. SQL Server books online is the most ideal place
to read over throughout SQL Server architecture. Read up the chapter dedicated
to SQL Server Architecture.
What is lock escalation?
Lock escalation is the technique of converting a lot of low total amount locks
(like row locks, web page locks) to better grade locks (like table
locks). Every lock is a memory house too most locks is able to mean,
more memory making populated by locks. To hold off their based on what i read in happening,
SQL Server escalates the a large number of fine-grain locks to a lower amount of coarse-grain
locks. Lock escalation threshold was definable in SQL Server 6.5, but
from SQL Server 7.0 onwards it is dynamically strive by SQL Server.
What's the change between DELETE TABLE and TRUNCATE TABLE commands?
DELETE TABLE is a logged operation, so the deletion of every row gets
logged in the purchase log, that affects it slow. TRUNCATE TABLE
also deletes all the rows in a table, but it will not log the deletion of
each row, rather it logs the deallocation of the information web sites of the
table, that causes it faster. Of course, TRUNCATE TABLE can be rolled
back.
Explain the storage examples of OLAP
Check out MOLAP, ROLAP and HOLAP in SQL Server books online for more
infomation.
What are the new parts introduced in SQL Server 2000 (or the latest
release of SQL Server at the while of your interview)? What changed
between the first version of SQL Server and the contemporary version?
This measure is usually surveyed to see how up to date is your knowledge.
Generally there is a section in the begun of the books online
titled "What's New", that has all this type of information. Of course,
reading just now who is not enough, you may experience tried people conditions to
better solution the questions. Also assess out the section titled
"Backward Compatibility" in books online that talks close to the changes
that undergo taken place in the new version.
What are constraints? Explain several sorts of constraints.
Constraints enable the RDBMS enforce the integrity of the database
automatically, without needing you to form triggers, fundamental or defaults.
Types of constraints: NOT NULL, CHECK, UNIQUE, PRIMARY KEY, FOREIGN KEY
For an rationale of these types of constraints see books online for the pages
titled: "Constraints" and "CREATE TABLE", "ALTER TABLE"
Whar is an index? What are the sorts of indexes? How multiple clustered
indexes can be made on a table? I construct a separate index on each
column of a table. how are the benefits and disadvantages of this
approach?
Indexes in SQL Server are similar to the indexes in books. They help
SQL Server retrieve the info quicker.
Indexes are of two types. Clustered indexes and non-clustered indexes.
When you craete a clustered index on a table, all the rows in the
table are stored in the shape of the clustered index key. So, there
can be just one clustered index per table. Non-clustered indexes have
their own storage separate based on data from the table info storage. Non-clustered
indexes are stored as B-tree homes (so do clustered indexes),
with the leaf grade nodes in posession of the index key and it is row locater.
The row located can be the RID or the Clustered index key, depending
up on the absence or occurrence of clustered index on the table.
If you initiate an index on every column of a table, it improves the
query performance, as the query optimizer can decide on based on information from all the
existing indexes to arrive up providing an small execution plan. At the
same t ime, info revision operations (such as INSERT, UPDATE,
DELETE) might become slow, as each age info fluxes in the table, all
the indexes fancy to be updated. Another disadvantage is that, indexes
need disk space, the !no! indexes you have, other disk space is used.
Back to top
Database administration (top)
What is RAID and how are unusual sorts of RAID configurations?
RAID stands for Redundant Array of Inexpensive Disks, used up to provide
fault tolerance to database servers. There are six RAID numbers 0
through 5 submiting strange value of performance, fault tolerance.
MSDN has a good deal of data right about RAID values and for detailed
information, examine out the RAID advisory board's homepage
What are the steps you serves to take to boost performance of a poor
performing query?
This is a essentially open concluded ask and there could easily be a lot of reasons
behind the faulty performance of a query. But selected whole difficulties that
you are able to jargon roughly ought to be: No indexes, table scans, missing or out
of date statistics, blocking, excess recompilations of stored
procedures, rules and triggers without SET NOCOUNT ON, poorly
written query amidst unnecessarily complicated joins, too much
normalization, excess usage of cursors and temporary tables.
Some of the tools/ways this assistance you troubleshooting performance
problems are: SET SHOWPLAN_ALL ON, SET SHOWPLAN_TEXT ON, SET
STATISTICS IO ON, SQL Server Profiler, Windows NT /2000 Performance
monitor, Graphical execution initiative in Query Analyzer.
Download the grey paper on performance tuning SQL Server from
Microsoft web site. Don't forget to evaluate out sql-server-performance.com
What are the steps you would take, if you are tasked among securing an
SQL Server?
Again now is one more open finished question. Here are Other details you
could lingo about: Preferring NT authentication, making the most of server, databse
and software roles to control entrance to the data, securing the
physical database files employing NTFS permissions, making use of an unguessable
SA password, restricting physical entrance to the SQL Server, renaming
the Administrator consideration on the SQL Server computer, disabling the
Guest account, enabling auditing, paying off multiprotocol encryption,
setting up SSL, setting up firewalls, isolating SQL Server for the
web server etc.
Read the grey paper on SQL Server security according to Microsoft website.
Also inspect out My SQL Server security proper practices
What is a deadlock and how is a reside lock? How am able to you go about
resolving deadlocks?
Deadlock is a circumstances when two processes, every invested in a lock on one
piece of data, try to obtain a lock on the other's piece. Each
process may wait eternally for the opposite to release the lock,
unless one of the user manages is terminated. SQL Server detects
deadlocks and terminates one user's process.
A livelock is one, at which a ask for for an exclusive lock is
repeatedly denied while a string of overlapping shared locks keeps
interfering. SQL Server detects the condition once two denials and
refuses a large amount of shared locks. A livelock furthermore takes place when read
transactions monopolize a table or page, forcing a come up with transaction
to wait indefinitely.
Check out SET DEADLOCK_PRIORITY and "Minimizing Deadlocks" in SQL
Server books online. Also look over out the content Q169960 based on information from Microsoft
knowledge base.
What is blocking and how ought to you troubleshoot it?
Blocking takes place when one connection for an software holds a lock
and a instant connection requires a conflicting lock type. This forces
the minute connection to wait, blocked on the first.
Read up the next concerns in SQL Server books online: Understanding
and averting blocking, Coding tiny transactions.
Explain CREATE DATABASE syntax
Many of us are spent to craeting databases from what i read in the Enterprise Manager
or by just now furnishing the command: CREATE DATABAE MyDB. But how if you
have to build a database amid two filegroups, one on impel C and the
other on force D through log on urge E amid an previous size of 600 MB
and provided a increment cog of 15%? That's why making a DBA you as long as be
familiar through the CREATE DATABASE syntax. Check out SQL Server books
online for more and more information.
How to restart SQL Server in single user mode? How to initiate SQL Server
in tiny configuration mode?
SQL Server can be began on command line, making use of the SQLSERVR.EXE.
This EXE has a couple of particularly monumental parameters in that a DBA will be
familiar with. -m is depleted for appearing SQL Server in single user mode
and -f is spent to initiate the SQL Server in pithy confuguration mode.
Check out SQL Server books online for !no! parameters and their
explanations.
As a half of your job, how are the DBCC commands such a you commonly
use for database maintenance?
DBCC CHECKDB, DBCC CHECKTABLE, DBCC CHECKCATALOG, DBCC CHECKALLOC,
DBCC SHOWCONTIG, DBCC SHRINKDATABASE, DBCC SHRINKFILE etc. But there
are a entire mountain of DBCC commands that are essentially useful for DBAs.
Check out SQL Server books online for a larger number of information.
What are statistics, underneath how shape properties go out of date, how
do you update them?
Statistics determine the selectivity of the indexes. If an indexed
column has top notch cost levels next the selectivity of such a index is more,
as opposed to an index providing non-unique values. Query optimizer uses
these indexes in determining whether to decide on an index or not while
executing a query.
Some circumstances below that you must update statistics:
1) If there is major tweak in the key market values in the index
2) If a considerable quantity of information in an indexed column has been heard added,
changed, or removed (that is, if the distribution of key price has
changed), or the table has continued truncated making use of the TRUNCATE TABLE
statement and at that time repopulated
3) Database is upgraded from what i read in a earliest version
Look up SQL Server books online for the coming commands: UPDATE
STATISTICS, STATS_DATE, DBCC SHOW_STATISTICS, CREATE STATISTICS, DROP
STATISTICS, sp_autostats, sp_createstats, sp_updatestats
What are the multitude of ways of moving data/databases between servers
and databases in SQL Server?
There are oodles of opportunities available, you own to decide your option
depending upon your requirements. Some of the opportunities you hold are:
BACKUP/RESTORE, dettaching and attaching databases, replication, DTS,
BCP, logshipping, INSERT...SELECT, SELECT...INTO, generating INSERT
scripts to make data.
Explian weird sorts of BACKUPs avaialabe in SQL Server? Given a
particular scenario, how can you go something like opting for a backup plan?
Types of backups you can initiate in SQL Sever 7.0+ are Full database
backup, differential database backup, arrangement log backup,
filegroup backup. Check out the BACKUP and RESTORE commands in SQL
Server books online. Be willing to spit out the commands in your
interview. Books online additionally has data on detailed
backup/restore architecture and when one providing go for a particular
kind of backup.
What is database replicaion? What are the diverse sorts of
replication you can set up in SQL Server?
Replication is the technique of copying/moving info between databases on
the same or multiple servers. SQL Server emphasizes the next types
of replication scenarios:
* Snapshot replication
* Transactional replication (with immediate updating subscribers,
with queued updating subscribers)
* Merge replication
See SQL Server books online for indepth indemnity on replication. Be
prepared to explain how strange replication realtors function, what
are the number one process tables expended in replication etc.
How to determine the benefits pack by now installed on SQL Server?
The intercontinental variable @@Version stores the fashion total number of the
sqlservr.exe, that is exhausted to determine the treatment pack installed.
To appreciated further in regards to that procedure visit SQL Server assistance packs and
versions.
Back to top
Database programming (top)
What are cursors? Explain several sorts of cursors. What are the
disadvantages of cursors? How can you prevent cursors?
Cursors let row-by-row prcessing of the resultsets.
Types of cursors: Static, Dynamic, Forward-only, Keyset-driven. See
books online for supplementary information.
Disadvantages of cursors: Each cycle you fetch a row of the cursor,
it possible results in a network roundtrip, at which as a conventional SELECT query
makes just one rowundtrip, but then larger the resultset is. Cursors are
also steep when properties motivate larger amount of equipment and temporary storage
(results in a good amount IO operations). Furthere, there are restrictions on
the SELECT statements which can be expended in on a little sorts of cursors.
Most of the times, set rooted operations can be expended rather of
cursors. Here is an example:
If you experience to offer a flat hike to your workforces paying off the following
criteria:
Salary between 30000 and 40000 -- 5000 hike
Salary between 40000 and 55000 -- 7000 hike
Salary between 55000 and 65000 -- 9000 hike
In that state a good number of developers have a propensity to use a cursor, determine each
employee's salary and update his salary according to the above
formula. But the same can be reached by numerous update statements or
can be combined in a single UPDATE statement as substantiated below:
UPDATE tbl_emp SET salary =
CASE WHEN salary BETWEEN 30000 AND 40000 THEN salary + 5000
WHEN salary BETWEEN 40000 AND 55000 THEN salary + 7000
WHEN salary BETWEEN 55000 AND 65000 THEN salary + 10000
END
Another problem in that developers have a tendency to use cursors: You seek to
call a stored process when a column in a individual row meets
certain condition. You do not experience to use cursors for this. This can be
achieved making the most of WHILE loop, as extensively as there is a different key to
identify every row. For tendencies of paying WHILE loop for row by row
processing, take a look at out the 'My code library' section of my site or
search for WHILE.
Write decreased the overall syntax for a SELECT statements covering all the
options.
Here's the easy syntax: (Also checkout SELECT in books online for
advanced syntax).
SELECT select_list
[INTO new_table_]
FROM table_source
[WHERE search_condition]
[GROUP BY group_by__expression]
[HAVING search_condition]
[ORDER BY order__expression [ASC | DESC] ]
What is a join and explain unusual kinds of joins.
Joins are used up in problems to explain how strange tables are related.
Joins moreover let you specific info of a table depending upon information from
another table.
Types of joins: INNER JOINs, OUTER JOINs, CROSS JOINs. OUTER JOINs are
further classified as LEFT OUTER JOINS, RIGHT OUTER JOINS and FULL
OUTER JOINS.
For a great deal more tips see web sites based on data from books online titled: "Join
Fundamentals" and "Using Joins".
Can you undergo a nested transaction?
Yes, really much. Check out BEGIN TRAN, COMMIT, ROLLBACK, SAVE TRAN and
@@TRANCOUNT
What is an long stored procedure? Can you instantiate a COM object
by paying for T-SQL?
An long stored course is a function during a DLL (written in a
programming terminology as C, C++ paying for Open Data Services (ODS) API)
that can be referred to as based on information from T-SQL, simply the way we employ standard stored
procedures paying for the EXEC statement. See books online to decide how to
create long stored rules and how to add them to SQL Server.
Yes, you can instantiate a COM (written in languages want VB, VC++)
object based on what i read in T-SQL by employing sp_OACreate stored procedure. Also see
books online for sp_OAMethod, sp_OAGetProperty, sp_OASetProperty,
sp_OADestroy. For an model of producing a COM object in VB and
calling it from what i read in T-SQL, see 'My code library' section of currently site.
What is the method function to get the the most recent user's user id?
USER_ID(). Also assess out a greater number of method runs want USER_NAME(),
SYSTEM_USER, SESSION_USER, CURRENT_USER, USER, SUSER_SID(), HOST_NAME().
What are triggers? How multi triggers you can experience on a table? How to
invoke a rationale on demand?
Triggers are special type of stored plan overly get executed
automatically when an INSERT, UPDATE or DELETE utilization takes place
on a table.
In SQL Server 6.5 you serves to define merely 3 triggers per table, one for
INSERT, one for UPDATE and one for DELETE. From SQL Server 7.0
onwards, the present restriction is gone, and you might compose multiple
triggers per every action. But in 7.0 there is no way to control the
order in that the triggers fire. In SQL Server 2000 you am able to specify
which instigate fires first and foremost or fires go on making use of sp_settriggerorder
Triggers can not be invoked on demand. They get triggered easily when an
associated action (INSERT, UPDATE, DELETE) takes place on the table on
which properties are defined.
Triggers are normally used up to craft market rules, auditing.
Triggers can too be spent to give the referential integrity checks,
but wherever possible, use constraints for presently purpose, alternatively of
triggers, as constraints are still faster.
Till SQL Server 7.0, triggers fire one and only in the wake of the info modification
operation happens. So in a way, properties are identified give triggers. But in
SQL Server 2000 you would engender pre triggers also. Search SQL Server
2000 books online for INSTEAD OF triggers.
Also assess out books online for 'inserted table', 'deleted table' and
COLUMNS_UPDATED()
There is a lead to defined for INSERT operations on a table, in an
OLTP system. The reason is written to instantiate a COM object and
pass the newly insterted rows to it for select individualized processing. What
do you agree of this moment implementation? Can the be calculated better?
Instantiating COM objects is a second consuming technique and as of you
are working at it based on what i read in within the duration of a trigger, it slows low the info insertion
process. Same is the circumstances providing sending emails based on triggers. This
scenario can be higher designed by logging all the pertinent data
into a separate table, and hold a job that periodically checks this
table and performs the needful.
What is a self join? Explain it in on an example.
Self join is only such as any more and more join, apart from such a two instances of
the same table can be joined in the query. Here is an example:
Employees table that contains rows for standard workforces as far as
managers. So, to submit out the managers of all the employees, you need
a self join.
CREATE TABLE emp
(
empid int,
mgrid int,
empname char(10)
)
INSERT emp SELECT 1,2,'Vyas'
INSERT emp SELECT 2,3,'Mohan'
INSERT emp SELECT 3,NULL,'Shobha'
INSERT emp SELECT 4,2,'Shridhar'
INSERT emp SELECT 5,2,'Sourabh'
SELECT t1.empname [Employee], t2.empname [Manager]
FROM emp t1, emp t2
WHERE t1.mgrid = t2.empid
Here's an advanced query paying off a LEFT OUTER JOIN the current a good deal takings the
employees without managers (super bosses)
SELECT t1.empname [Employee], COALESCE(t2.empname, 'No manager') [Manager]
FROM emp t1
LEFT OUTER JOIN
emp t2
ON
t1.mgrid = t2.empid
Offshore Software Development Success Steps
An interesting event is cropping up amid the numerous outsourcing deals smacked in the endure multiple years. Rather as opposed to losing less, outsourced tool projects are toping such a budgets and are often riddled through bugs. What's interesting is such a there are indeed rates savings in the the beginning of ages of outsourcing deals, but such savings often disappear in the fourth year.
In 2005, IT consultancy DiamondCluster International reported such a the plethora of people satisfied providing this offshore providers come down to 62 per cent based on what i read in 79 percent. What's more, 51 per cent of families terminated such a outsourcing projects the beginning of -- a doubling within the duration of earliest years. Also in 2005, PricewaterhouseCoopers at last found the present portion of the financing services executives it report got dissatisfied through offshoring. And lastly, a prediction by Deloitte Touche Tohmatsu found the performance of outsourcing organizations had an alarming drop-off in both prices and savings ensuing 3 years.
So why do circumstances go sour? According to Philip Hatch of Ventoro, an offshore outsourcing consultancy cites a few reasons namely increased turnover rates; obsolete methodologies and processes; and greater amount of soft costs. CIO Magazine gives the coming 7 seven steps to boon ensure perpetual achievement through offshore application development projects.
1. Offshore relationships make continuing improvement all over the place such a lifecycles. In particular, it is necessary to re-examine them carefully any 3 years.
2. Once the condition has kept on closed, the senior-level representation based on data from the offshore organization may disappear for day-to-day activities. Insist which properties balance quarterly so the properties stay engaged in on the account.
3. Don't leave the same body in credit of managing the relationship for a larger number of as opposed to a 2 or 3 years. After this moment number of time, burnout is normal to set in. Alternatively, contemplate possessing one permanently stationed at the offshore site. This may destroy the would like for a good deal of the travel overly a US-based employee may experience to sell with.
4. Keep end tabs on turnover at the offshore company. Frequent departures on any floor can be disruptive to projects and can stand for as a caution signal of situations to come.
5. Make explicit plans through the offshore provider to bargain amidst and pillow against the unanticipated reduction of key employees. All projects experience key players whose departure can grind a project's progress to a halt.
6. Develop performance metrics who are in chain in on reality. Avoid the fluffy, nice-to-look-at metrics and focus on how can in effect be acted upon.
7. Check in among sector users and internal IT workforces to get a deal with on this experiences in on such a counterparts at the offshore company. They can post data at the grassroots amount something like how day-to-day activities are handled.
In 2005, IT consultancy DiamondCluster International reported such a the plethora of people satisfied providing this offshore providers come down to 62 per cent based on what i read in 79 percent. What's more, 51 per cent of families terminated such a outsourcing projects the beginning of -- a doubling within the duration of earliest years. Also in 2005, PricewaterhouseCoopers at last found the present portion of the financing services executives it report got dissatisfied through offshoring. And lastly, a prediction by Deloitte Touche Tohmatsu found the performance of outsourcing organizations had an alarming drop-off in both prices and savings ensuing 3 years.
So why do circumstances go sour? According to Philip Hatch of Ventoro, an offshore outsourcing consultancy cites a few reasons namely increased turnover rates; obsolete methodologies and processes; and greater amount of soft costs. CIO Magazine gives the coming 7 seven steps to boon ensure perpetual achievement through offshore application development projects.
1. Offshore relationships make continuing improvement all over the place such a lifecycles. In particular, it is necessary to re-examine them carefully any 3 years.
2. Once the condition has kept on closed, the senior-level representation based on data from the offshore organization may disappear for day-to-day activities. Insist which properties balance quarterly so the properties stay engaged in on the account.
3. Don't leave the same body in credit of managing the relationship for a larger number of as opposed to a 2 or 3 years. After this moment number of time, burnout is normal to set in. Alternatively, contemplate possessing one permanently stationed at the offshore site. This may destroy the would like for a good deal of the travel overly a US-based employee may experience to sell with.
4. Keep end tabs on turnover at the offshore company. Frequent departures on any floor can be disruptive to projects and can stand for as a caution signal of situations to come.
5. Make explicit plans through the offshore provider to bargain amidst and pillow against the unanticipated reduction of key employees. All projects experience key players whose departure can grind a project's progress to a halt.
6. Develop performance metrics who are in chain in on reality. Avoid the fluffy, nice-to-look-at metrics and focus on how can in effect be acted upon.
7. Check in among sector users and internal IT workforces to get a deal with on this experiences in on such a counterparts at the offshore company. They can post data at the grassroots amount something like how day-to-day activities are handled.
Check Offshore Custom Software Development Failure and Success Factors
Bespoke program development or personalized application development is approximately developing program centered on shopper requirements. The predict scope starts in on taking out the preliminary requirements, astronomical grade lose of the project, things specification discussion, ultimate scope of leg work along provided loss and milestones, execution and development and delivery and maintenance.
Almost 70% the service projects fails either not meeting the timelines or overshooting of budget and a good number of critical missing the amenities and delivering the unforeseen closing product. The the majority of essential half of offshore software development association is to deliver the concluding product this meets the patron estimates meeting timelines, price levels and quality.
There are multiple components to be kept in mind in circumstances to deliver the likely superiority product.
Requirement Analysis: Correct necessity analysis is the key to the prosperity of the project. Client may not be able to produce complete amenities at the commence of the project. The offshore tool development cluster ought to discuss the things provided the customer and setup the expectation levels. The baselines tied to be worth and worthy and scope have got to moreover be defined.
Structural Designing: Based on arrangements collected residence designing should be carried out in the shape of ER Diagrams, Data flows and have got to be proven by the client. Feasibility article is to be wound up for the technology to be used. Based on the closing output the scope baseline have got to be set which has to be judged to be over development of the project. Risk identification is be wrapped up before begun the development in shape to mitigate or accept the odds faced in the presume and the same is to be imparted upon to the client.
Development: Once the baselines are set the development committe can craft making an effort on the equipments laid low in scope. Offshore development council anticipate manager needs to furnish the status scores as expected. Depending on presume complexity and development methodology, diverse worthy tests are to be executed to ensure meeting of the customer expectations.
Almost 70% the service projects fails either not meeting the timelines or overshooting of budget and a good number of critical missing the amenities and delivering the unforeseen closing product. The the majority of essential half of offshore software development association is to deliver the concluding product this meets the patron estimates meeting timelines, price levels and quality.
There are multiple components to be kept in mind in circumstances to deliver the likely superiority product.
Requirement Analysis: Correct necessity analysis is the key to the prosperity of the project. Client may not be able to produce complete amenities at the commence of the project. The offshore tool development cluster ought to discuss the things provided the customer and setup the expectation levels. The baselines tied to be worth and worthy and scope have got to moreover be defined.
Structural Designing: Based on arrangements collected residence designing should be carried out in the shape of ER Diagrams, Data flows and have got to be proven by the client. Feasibility article is to be wound up for the technology to be used. Based on the closing output the scope baseline have got to be set which has to be judged to be over development of the project. Risk identification is be wrapped up before begun the development in shape to mitigate or accept the odds faced in the presume and the same is to be imparted upon to the client.
Development: Once the baselines are set the development committe can craft making an effort on the equipments laid low in scope. Offshore development council anticipate manager needs to furnish the status scores as expected. Depending on presume complexity and development methodology, diverse worthy tests are to be executed to ensure meeting of the customer expectations.
How to Structure an IT Outsourcing Project: IT Contract and Agreement
Firstly, you would like to identify the sort of outsourcing example you may covet to adopt. Once you experience resolved the model, the imminent contract and agreements ask for every situation.
Master Services Agreement:
A Master Services Agreement or MSA is apt for contracts of even greater worth and longer duration. This agreement ought to paint a lot of corporate quality procedures this otherwise seek to be included in specific attempt orders.
MSA, in the wake of agreed and signed by the vendor could act as an umbrella agreement underneath that Work Orders or Schedule(s) of Work or SoWs are able to be articulated.
If the contract is of shorter length and if you do not experience a extensively directed strategy to hard work surrounded by a vendor, when that happens an MSA am able to not trigger sense.
Typical MSA should undergo a job of 3 or 5 years.
Further, MSA may not put in any select imagine tethered clauses. These clauses and Service Level Agreement (SLA) clauses as long as be assembled to specific Work Orders or Statement of Work or SoW.
Under an MSA, you can run Staff Augmentation make every effort orders, Managed Services try orders, Fixed Bid make every effort orders and Managed Capacity tedious work orders.
In a few situations, Business operates are able to like to directly run IT projects, but may not undergo the cycle to delegate towards formalizing a complicated outsourcing contract. This is at which MSA plays a big role and the boom is able to own to only housing a supervised condition or SoW tethered to the MSA.
Work Order or Schedule of Work or Statement of Work (SoW):
A Work Order or WO, or Schedule of Work or SoW has to be built for specific programs of directed so needs to be outsourced.
There are weird flavours of SoWs depending upon the brand of outsourcing example this you plans to pursue for exact programs of work.
There am able to be a Staff Augmentation (SA) SoW, add SLAs and deliverables to the SA version and you am able to get a Time & Material version, a Managed Services SoW and a Fixed Bid SoW.
Master Services Agreement:
A Master Services Agreement or MSA is apt for contracts of even greater worth and longer duration. This agreement ought to paint a lot of corporate quality procedures this otherwise seek to be included in specific attempt orders.
MSA, in the wake of agreed and signed by the vendor could act as an umbrella agreement underneath that Work Orders or Schedule(s) of Work or SoWs are able to be articulated.
If the contract is of shorter length and if you do not experience a extensively directed strategy to hard work surrounded by a vendor, when that happens an MSA am able to not trigger sense.
Typical MSA should undergo a job of 3 or 5 years.
Further, MSA may not put in any select imagine tethered clauses. These clauses and Service Level Agreement (SLA) clauses as long as be assembled to specific Work Orders or Statement of Work or SoW.
Under an MSA, you can run Staff Augmentation make every effort orders, Managed Services try orders, Fixed Bid make every effort orders and Managed Capacity tedious work orders.
In a few situations, Business operates are able to like to directly run IT projects, but may not undergo the cycle to delegate towards formalizing a complicated outsourcing contract. This is at which MSA plays a big role and the boom is able to own to only housing a supervised condition or SoW tethered to the MSA.
Work Order or Schedule of Work or Statement of Work (SoW):
A Work Order or WO, or Schedule of Work or SoW has to be built for specific programs of directed so needs to be outsourced.
There are weird flavours of SoWs depending upon the brand of outsourcing example this you plans to pursue for exact programs of work.
There am able to be a Staff Augmentation (SA) SoW, add SLAs and deliverables to the SA version and you am able to get a Time & Material version, a Managed Services SoW and a Fixed Bid SoW.
IT Sector Baseline Risk Assessment - Information Technology Sector
Abstract: The Information Technology (IT) Sector gives both offerings and services which substantiation the compressed deployment of today's worldwide information-based society. These packages and services are integral to the operations and services only if by a greater amount of major infrastructure and key resource (CIKR) sectors. Threats to the IT Sector are complex and varied.
In addition to the odds presented by normal hazards? these kinds of as catastrophic weather or seismic events?the IT Sector in addition faces threats based on what i read in criminals, hackers, terrorists, and nation-states, all of whom experience shown a fluctuating degree of capabilities and intentions to attack important IT Sector functions.
Additionally, manmade threats to the IT Sector are too speedily evolving based on what i read in clear automated worms and viruses to complex social engineering incidents the feat well&wshyp;known and unknown vulnerabilities in packages and services matured by the IT Sector.
While existent security and response capabilities mitigate a large number of of such threats, the IT Sector nevertheless faces Sector-wide likelihood to its ability to find hardware, software, and services to funny things CIKR sectors.
Due to the IT Sector's insane degree of interdependency investing in a multitude of CIKR sectors and the continuously evolving threat landscape, reviewing vulnerabilities and estimating consequence is difficult. Therefore, these kinds of questions should be dealt in a collaborative and flexible framework the enables the public and private sectors to increment the resiliency and security of the rule IT Sector functions.
In addition to the odds presented by normal hazards? these kinds of as catastrophic weather or seismic events?the IT Sector in addition faces threats based on what i read in criminals, hackers, terrorists, and nation-states, all of whom experience shown a fluctuating degree of capabilities and intentions to attack important IT Sector functions.
Additionally, manmade threats to the IT Sector are too speedily evolving based on what i read in clear automated worms and viruses to complex social engineering incidents the feat well&wshyp;known and unknown vulnerabilities in packages and services matured by the IT Sector.
While existent security and response capabilities mitigate a large number of of such threats, the IT Sector nevertheless faces Sector-wide likelihood to its ability to find hardware, software, and services to funny things CIKR sectors.
Due to the IT Sector's insane degree of interdependency investing in a multitude of CIKR sectors and the continuously evolving threat landscape, reviewing vulnerabilities and estimating consequence is difficult. Therefore, these kinds of questions should be dealt in a collaborative and flexible framework the enables the public and private sectors to increment the resiliency and security of the rule IT Sector functions.