SQL Server Performance Forum – Threads Archive

Alias table imporve performance or?

Hi, Lets say I’ve a sql statement called select emp.fname, emp.lname, emp.dob from employee emp. I would like to know the alias will increase the performance or no difference. Thanks,
Prabakar

No difference in the performance and the readability of a SELECT statement can be improved by giving a table an alias, also known as a correlation name or range variable. Satya SKJ
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No difference, but sometimes required.
———————–
–Frank
http://www.insidesql.de
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No difference, but you cannot use alias in every clause of a query. For example this query will not compile:
SELECT MAX(table1_id) AS max_table1_id
FROM table1_id
GROUP BY column1
WHERE max_table1_id > 10
— Marek Grzenkowicz

Your example won’t compile at all. No matter whether you use an alias or not. [<img src=’/community/emoticons/emotion-5.gif’ alt=’

‘ />] This is the syntax for SELECT… <pre> 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 ] ] </pre> ———————– –Frank http://www.insidesql.de</a> ———————–

<blockquote id="quote">quote:<hr height="1" id="quote" noshade="noshade">Originally posted by FrankKalis Your example won’t compile at all. No matter whether you use an alias or not. [<img src="http://sql-server-performance.com/community/emoticons/emotion-5.gif" alt="

">]<hr height="1" id="quote" noshade="noshade"></blockquote>You’re right. I meant something like this: <pre>SELECT MAX(table1_id) AS max_table1_id FROM table1 GROUP BY column1 HAVING max_table1_id > 10</pre>– Marek Grzenkowicz

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