From hamcdc@yahoo.co.uk Mon, 04 Feb 2002 14:30:35 -0800 From: =?iso-8859-1?q?Connor=20McDonald?= Date: Mon, 04 Feb 2002 14:30:35 -0800 Subject: Re: Which is more efficient For vs FORALL Message-ID: MIME-Version: 1.0 Content-Type: text/plain Is there any problem with doing does a straight update with no PL/SQL ? Thats typically the most efficient way. hth connor --- Rick_Cale@teamhealth.com wrote: > Hi DBAs > > Here are 2 scenario's. Which one is more efficient? > Assume 10,000 records to update > > Thanks > Rick > > 1. For each record update field1 with subsquery > Assume cursor is declared > FOR cursor_rec IN new_patients_cur LOOP > UPDATE > SET field1 = > (SELECT value > FROM table > WHERE ...) > WHERE .... > END LOOP; > > 2. For each record load nested table with data then > update all records with > a single FORALL > > t_type1 IS TABLE OF table1.field1%TYPE; > v_type1 t_type1(10000); > > /* Load the PLSQL nested table */ > FOR cursor_rec IN new_patients_cur LOOP > v_loop_ctr := v_loop_ctr + 1; > v_type1 := cursor_rec.field1; > END LOOP; > > /* INSERT all 10,000 records with on context switch > */ > FORALL v_count IN 1...10000) > UPDATE field1 = v_type1(v_count); > > > > -- > Please see the official ORACLE-L FAQ: > http://www.orafaq.com > -- > Author: > INET: Rick_Cale@teamhealth.com > > Fat City Network Services -- (858) 538-5051 FAX: > (858) 538-5051 > San Diego, California -- Public Internet > access / Mailing Lists > -------------------------------------------------------------------- > To REMOVE yourself from this mailing list, send an > E-Mail message > to: ListGuru@fatcity.com (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). ===== Connor McDonald http://www.oracledba.co.uk (mirrored at http://www.oradba.freeserve.co.uk) "Some days you're the pigeon, some days you're the statue" __________________________________________________ Do You Yahoo!? Everything you'll ever need on one web page from News and Sport to Email and Music Charts http://uk.my.yahoo.com -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: =?iso-8859-1?q?Connor=20McDonald?= INET: hamcdc@yahoo.co.uk Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051 San Diego, California -- Public Internet access / Mailing Lists -------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: ListGuru@fatcity.com (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).