Re: How to speed up Exclusive Locking
| От | Bernd Helmle |
|---|---|
| Тема | Re: How to speed up Exclusive Locking |
| Дата | |
| Msg-id | 378dea27826636cae6e28ff7ef9cce80@oopsware.de обсуждение исходный текст |
| Ответ на | How to speed up Exclusive Locking (David Goodenough <david.goodenough@btconnect.com>) |
| Ответы |
Re: How to speed up Exclusive Locking
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| Список | pgsql-general |
On Tue, 5 Dec 2006 10:18:21 +0000, David Goodenough <david.goodenough@btconnect.com> wrote: [...] > The first bits of the sync are done without locking the source tables, and > I do these until I find less than some suitable threshold of records > needing > to be updated. Then I lock the source tables and do the final sync. > > The statements issued to lock each table is:- > LOCK TABLE table IN EXCLUSIVE MODE; SELECT 1 FROM table; > So why selecting '1' for each row after locking the relation before? I don't know HA-JDBC but this looks really useless. Remove the SELECT and use the LOCK TABLE command within the transaction which does the sync for you. Bernd
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