Re: Can I use row-level locks to sequence READ COMMITTED transactions?
От | Craig Sturman |
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Тема | Re: Can I use row-level locks to sequence READ COMMITTED transactions? |
Дата | |
Msg-id | KJELLKKDKPLBALHNIIIHIEFPCCAA.craig@emedscentral.com обсуждение исходный текст |
Ответ на | Re: Can I use row-level locks to sequence READ COMMITTED transactions? (Tom Lane <tgl@sss.pgh.pa.us>) |
Ответы |
Re: Can I use row-level locks to sequence READ COMMITTED transactions?
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Список | pgsql-general |
Actually, I was having problems with restoring a pg dump too although it may be tied to my date settings. I changed my date format to non-US and I periodically get an email containing the following: From: Cron Daemon [mailto:root@hades.emedscentral] Sent: July 22, 2002 4:00 AM To: postgres@hades.emedscentral Subject: Cron <postgres@hades> [ -x /usr/lib/postgresql/bin/do.maintenance ] && /usr/lib/postgresql/bin/do.maintenance -a NOTICE: Conflicting settings for date NOTICE: Conflicting settings for date NOTICE: Conflicting settings for date NOTICE: Conflicting settings for date NOTICE: Conflicting settings for date When I try to restore a dumped database, this error comes back up along with the following user error: craig@hades:~$ psql polaris < /home/craig/enigma.dump NOTICE: Conflicting settings for date \connect: FATAL 1: IDENT authentication failed for user "postgres" craig@hades:~$ Anyone know where else I should change my date format and whether this could be causing the ident problem? Both the database and dump file are owned by the user craig. This is all under PostgreSQL 7.2.1 on a Debian woody system. Thanks, Craig S. -----Original Message----- From: pgsql-general-owner@postgresql.org [mailto:pgsql-general-owner@postgresql.org]On Behalf Of Tom Lane Sent: July 22, 2002 4:31 PM To: Matthew Woodcraft Cc: pgsql-general@postgresql.org Subject: Re: [GENERAL] Can I use row-level locks to sequence READ COMMITTED transactions? Matthew Woodcraft <mattheww@chiark.greenend.org.uk> writes: > If I use a READ COMMITTED transaction, the documentation says that a > query in my transaction may see changes which were committed by other > transactions after my transaction started. > My question is, is it guaranteed that a SELECT in my transaction will > see changes previously committed by other transactions, or is it only a > possibility? > By 'previously committed', I mean 'committed by a transaction which held > a row-level lock which my transaction has since obtained'. Yes, that will work. The SELECT sees rows that were committed at the instant it starts, which will be after the other xact completes if you use a FOR UPDATE lock. regards, tom lane ---------------------------(end of broadcast)--------------------------- TIP 2: you can get off all lists at once with the unregister command (send "unregister YourEmailAddressHere" to majordomo@postgresql.org)
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