Re: [GENERAL] shutdown gracefully & single user mode?
От | Moray McConnachie |
---|---|
Тема | Re: [GENERAL] shutdown gracefully & single user mode? |
Дата | |
Msg-id | 005f01beff4f$87d2c8f0$760e01a3@oucs.ox.ac.uk обсуждение исходный текст |
Ответ на | shutdown gracefully & single user mode? ("amy cheng" <amycq@hotmail.com>) |
Список | pgsql-general |
----- Original Message ----- From: Teodor Cimpoesu <teo@digiro.net> Cc: <pgsql-general@postgreSQL.org> Sent: Tuesday, September 14, 1999 5:11 PM Subject: Re: [GENERAL] shutdown gracefully & single user mode? I have not a lot of technical know-how on locking, but a couple of queries present themselves from this... Shouldn't step 0 be LOCK TABLE IN ACCESS EXCLUSIVE MODE ? & what happens to the lock immediately after the table is dropped and before it is recreated? At that stage if clients try to read from the table, should they get denied access by the lock, or should they get an error saying no such table? > gee :) > why don't you just : > 0. LOCK TABLE IN EXCLUSIVE MODE > 1. create a new table with the field adjusted to the needed size. > 2. INSERT INTO new_table SELECT ... FROM old_table ... > 3. DROP TABLE old_table > 4. ALTER TABLE new_table RENAME TO old_table > eventually within a transaction. > Also a SELECT INTO may be a shortcut, but I didn't test that. ---------------------------------------------------------------------------- ---------- Moray.McConnachie@computing-services.oxford.ac.uk
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