StackOverflow2013

Note that there are some explanatory texts on larger screens.

plurals

PO
text
Body
copied!<p>Try to use always the smallest datatype that you can and index all the fields most used in queries.</p> <p>Try to avoid server side cursors as much as possible. Always stick to a 'set-based approach' instead of a 'procedural approach' for accessing and manipulating data. Cursors can often be avoided by using SELECT statements instead.</p> <p>Always use the graphical execution plan in Query Analyzer or SHOWPLAN_TEXT or SHOWPLAN_ALL commands to analyze your queries. Make sure your queries do an "Index seek" instead of an "Index scan" or a "Table scan." A table scan or an index scan is a very bad thing and should be avoided where possible. Choose the right indexes on the right columns. Use the more readable ANSI-Standard Join clauses instead of the old style joins. With ANSI joins, the WHERE clause is used only for filtering data. Where as with older style joins, the WHERE clause handles both the join condition and filtering data. </p> <p>Do not let your front-end applications query/manipulate the data directly using SELECT or INSERT/UPDATE/DELETE statements. Instead, create stored procedures, and let your applications access these stored procedures. This keeps the data access clean and consistent across all the modules of your application, and at the same time centralizing the business logic within the database.</p> <p>Speaking about Stored procedures, do not prefix your stored procedure names with "sp_". The prefix sp_ is reserved for system stored procedure that ship with SQL Server. Whenever SQL Server encounters a procedure name starting with sp_, it first tries to locate the procedure in the master database, then it looks for any qualifiers (database, owner) provided, then it tries dbo as the owner. So you can really save time in locating the stored procedure by avoiding the "sp_" prefix.</p> <p>Avoid dynamic SQL statements as much as possible. Dynamic SQL tends to be slower than static SQL, as SQL Server must generate an execution plan every time at runtime.</p> <p>When is possible, try to use integrated authentication. It means, forget about the sa and others SQL users, use the microsoft user provisioning infra-structure and keep always your SQL server, up-to-date with all required patches. Microsoft do a good job developing, testing and releasing patches but it's your job to apply it.</p> <p>Search at amazon.com books with good reviews about it and buy it!</p>

Querying!

Guidance

An individual column

Larger individual text columns get their own page to allow for proper reading.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload