Re: table aliases save time when parsing??

[Igor Neyman]

Well, it's not aliases themselves, but the practice of using aliases as prefixes, when referring to columns:   SELECT t1.col1, t1.col2, t2.col1 FROM table1 t1, table2 t2 WHERE t1.col2 = t2.col2   that's what saves time when parsing: this way you tell the parser which table column list to look for, otherwise (when no prefixes used) it has to search through all tables column lists for particular column definition (and also to make sure, that this column name is unique in all column lists - if not you'll be getting an error, if not using prefixes).   But, you can get the same result (save time on parsing), when using table names as prefixes:   SELECT table1.col1, table1.col2, table2.col1 FROM table1, table2 WHERE table1.col2 = table2.col2   It's just that aliases are usually short (while table names could be long), and it's easier to read the code.   List, please correct me, if I'm wrong.   Igor Neyman, OCP DBA Perceptron, Inc. (734)414-4627 [EMAIL PROTECTED]   ----- Original Message ----- From: novicedba To: Multiple recipients of list ORACLE-L Sent: Tuesday, July 10, 2001 7:10 AM Subject: table aliases save time when parsing?? Hi,   was reading CorrelatedSubqueries.pdf from oriole corp. In fact it's good programming practice to use aliases in every situation where more than one table is referred to in a statement, since it saves time when parsing.   Can some one please explain how it helps?   coz I am a novice Oracle Certifiable DBBS