| From: | Andrew - Supernews <andrew+nonews(at)supernews(dot)com> |
|---|---|
| To: | pgsql-hackers(at)postgresql(dot)org |
| Subject: | Re: Exclusive lock for database rename |
| Date: | 2005-11-03 19:40:15 |
| Message-ID: | slrndmkpsv.g61.andrew+nonews@trinity.supernews.net |
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| Lists: | pgsql-hackers |
On 2005-11-03, Peter Eisentraut <peter_e(at)gmx(dot)net> wrote:
> Peter Eisentraut wrote:
>> Someone wanted to rename a database while someone else was running a
>> rather long pg_dump, so the rename had to wait, and everyone else had
>> to wait for the rename because no new connections would be allowed.
>
> As an auxiliary issue, why do the new connections have to wait in this
> case? The rename waits for the AccessShareLock of the dump to be
> released, but meanwhile new connections should be able to get
> AccessShareLocks of their own.
No. New AccessShare locks block behind the pending AccessExclusive lock.
Otherwise AccessShare locks could starve the exclusive lock forever.
--
Andrew, Supernews
http://www.supernews.com - individual and corporate NNTP services
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