Why do you say it shouldn't make a difference? It makes a huge difference CPU-wise. Remember you're dealing with a general regexp parsing library, and not an optimised Oracle kernel standard sql LIKE % query. regexp_like will never beat a LIKE % query. Forget looking at a sqlplus strace - the SQL is executed on the server, not the client. Check the CPU % of the 2 queries in the DB. That'll prove my point. Cheers, Phil On 12 Jan 2012, at 21:35, Herring Dave - dherri <Dave.Herring@xxxxxxxxxx> wrote: > Steve, > > I can't help with strace, but can give a suggestion with "regexp_like". Try > adding in the beginning-of-line and end-of-line anchors: > > regexp_like(index_name,'^.*(COL)+.*$') > > That *shouldn't* make a difference, but it does, at least under 10.2.0.2. I > had great intentions 3 yrs ago to performance test various options with > REGEXP functions in Oracle but unfortunately didn't find the time to make it > happen. If you figure out why the line anchors make it so much faster than > please share, as I've love to know. > > DAVID HERRING > DBA > Acxiom Corporation > EML dave.herring@xxxxxxxxxx > TEL 630.944.4762 > MBL 630.430.5988 > 1501 Opus Pl, Downers Grove, IL 60515, USA > WWW.ACXIOM.COM > > The information contained in this communication is confidential, is intended > only for the use of the recipient named above, and may be legally privileged. > If the reader of this message is not the intended recipient, you are hereby > notified that any dissemination, distribution or copying of this > communication is strictly prohibited. If you have received this communication > in error, please resend this communication to the sender and delete the > original message or any copy of it from your computer system. Thank you. > > -----Original Message----- > From: oracle-l-bounce@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx] On > Behalf Of Steve Gardiner > Sent: Thursday, January 12, 2012 8:40 AM > To: oracle-l@xxxxxxxxxxxxx > Subject: Oracle strace output - detail > > Oracle-l readers, > > > Does anyone have an idea how to decode this strace entry? Or where to > look for more info? > > 0.000222 read(11, > "\1w\0\0\6\0\0\0\0\0\20\27\0\0\0\307+\337\201\340\37\314\300\177p\334f\1 > -- //www.freelists.org/webpage/oracle-l