Article View: comp.databases.oracle.misc
Article #154Re: Prepare Statement and (Oracle's) SGA
From: AV
Date: Thu, 21 Jun 2001 04:08
Date: Thu, 21 Jun 2001 04:08
52 lines
3243 bytes
3243 bytes
I have similar observations. My guess [just a guess], for Oracle, it does not make difference -- source : sql-plus, jdbc, odbc, dbi.... -- owner: user, connection, preparedStatement ...similar requests will go to single "parse_call". please, see some comments below... "Alain Kreienbuhl" <alain.kreienbuhl@fisystem.com> wrote in message news:3B2F4D6B.72B1787E@fisystem.com... > Hello, > > We're using the PreparedStatement Object Pool provided in Websphere > AppServer with an Oracle 8.0.5 RDMS (yes I know :-) . > > At one time we had 3 connections alloted using the same query. Since a > PreparedStatement is associated with a Connection object at that time we > had 3 connections objects and 3 preparedStatement objects (1 / > connection). > > Now when we looked at the v$sql table regarding the specific query, we > noted that the parse_call was 1. This means that SGA cached the parsed > query. Now I understand that the SGA is buffer where come and go. Now > may question is this : > - Is it possible under heavy load that the SGA clears all parsed > query related to the preparedStatement object so that even if a > PreparedStatement is cache in the Application Server the parsed query > might be gone on the RDMS side; forcing to prase again the statement. I noted 20-60 sec average life-time for non-repeated request under average load. This time may vary a lot. > - Or do preparedStatement have a different life cycle so while the > connection is open no preparedStatement (associated to that connection) > is to be "Garbage collected" from the SGA. most probably Oracle does not care... and aged requests will be coolected... > - Because of the PreparedStatement Object Pool does the SGA size need > to be increased ? Count aproximate number of _different_ prepared Statement in your project. Most probably <1000 will not require adjustments.... Better talk with your DBA. > Thanks for your help. > > Alain. > AlexV
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X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 107d46,ce0a30a991f3a3e0 X-Google-Attributes: gid107d46,public X-Google-Thread: f99a8,ce0a30a991f3a3e0 X-Google-Attributes: gidf99a8,public X-Google-Thread: 1090f0,ce0a30a991f3a3e0 X-Google-Attributes: gid1090f0,public X-Google-ArrivalTime: 2001-06-20 21:10:49 PST Path: arc1-ca.pugleaf.net!archiver1.google.com!newsfeed.google.com!newsfeed.stanford.edu!news-spur1.maxwell.syr.edu!news.maxwell.syr.edu!news.stealth.net!wesley.videotron.net!weber.videotron.net.POSTED!not-for-mail From: "AV" <avek_nospam_@videotron.ca> Newsgroups: comp.databases.oracle.misc,comp.lang.java.databases,ibm.software.websphere.application-server References: <3B2F4D6B.72B1787E@fisystem.com> Subject: Re: Prepare Statement and (Oracle's) SGA Lines: 54 X-Priority: 3 X-MSMail-Priority: Normal X-Newsreader: Microsoft Outlook Express 5.50.4522.1200 X-MimeOLE: Produced By Microsoft MimeOLE V5.50.4522.1200 Message-ID: <CreY6.38093$VB5.2277081@weber.videotron.net> Date: Thu, 21 Jun 2001 00:08:48 -0400 NNTP-Posting-Host: 207.253.108.66 X-Complaints-To: abuse@videotron.net X-Trace: weber.videotron.net 993096546 207.253.108.66 (Thu, 21 Jun 2001 00:09:06 EDT) NNTP-Posting-Date: Thu, 21 Jun 2001 00:09:06 EDT