> >Dear all, > >Please find below the 2 queries : > >select dep_date from test_date1 >where to_char(dep_date,'dd-mon-yyyy') = >'12-jan-2002' > >select dep_date from test_date1 >where TRUNC(dep_date) = to_DATE( >'12-jan-2002','dd-mon-yyyy') > >The execution plan for both the queries shows a FTS >on test_date1. > >Execution Plan > 0 SELECT STATEMENT Optimizer=CHOOSE > 1 0 SORT (AGGREGATE) > 2 1 TABLE ACCESS (FULL) OF 'TEST_DATE1' > >The number of rows to be retrieved are 120010. > >The first query took 10msec to execute whereas the >second took about 2 >secs. > >Could anyone help me figure out what the problem >would be. > >TIA > >Best Regards >Jai >--------------------------------------------------- >-------
Which problem? I guess that, if the execution plans are identical, what you are experiencing is just the effect of caching. For a reason or another the data already was in memory in one case, and had to be loaded from disk in the other one. Check your trace statistics under SQL*Plus, logical IOs will probably be more or less identical and physical IOs wildly different. Note that as long as you apply a function to dep_date, your only way to escape the FTS is (supposing 8.1.7 or above) function-based indexes. If dep_date is indexed, then you should use something like dep_date >= some_date and dep_date < some_date + 1 instead of trunc(dep_date) = some_date It will allow for range scans. Regards, Stephane Faroult Oriole -- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: Stephane Faroult INET: [EMAIL PROTECTED] Fat City Network Services -- 858-538-5051 http://www.fatcity.com San Diego, California -- Mailing list and web hosting services --------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).