I think these two notes explain what's happening:Scalar subquery caching: http://jonathanlewis.wordpress.com/2006/11/06/filter-subqueries/
Deterministic Functions: http://www.jlcomp.demon.co.uk/deterministic.html Regards Jonathan Lewis http://jonathanlewis.wordpress.com Author: Cost Based Oracle: Fundamentals http://www.jlcomp.demon.co.uk/cbo_book/ind_book.html The Co-operative Oracle Users' FAQ http://www.jlcomp.demon.co.uk/faq/ind_faq.html----- Original Message ----- From: "Rich Jesse" <rjoralist@xxxxxxxxxxxxxxxxxxxxx>
To: "Oracle L" <oracle-l@xxxxxxxxxxxxx> Sent: Friday, July 10, 2009 10:45 PM Subject: Function in WHERE performance issue Hey all, In 10.1.0.5.0, I have two tables of IP and lat/long info of the CSV data from http://www.maxmind.com/app/geolitecity. PK on the location table is locid. PK on the block table is startipnum and endipnum, with a non-unique index on locid. There is an FK in the blocks table on location.locid. I created the IP-to-number function from here: http://cbmc64.blogspot.com/2005/05/oracle-plsql-function-to-convert_30.html ...and called it "ip2number" and made it DETERMINISTIC. I then tried this simple statement: select /*+ first_rows(1) */ aa.* from geo_location aa, geo_blocks b where aa.locid = b.locid and ip2number('192.168.1.1') between b.startipnum and b.endipnum; -- //www.freelists.org/webpage/oracle-l
