| From: | Heikki Linnakangas <heikki(dot)linnakangas(at)enterprisedb(dot)com> |
|---|---|
| To: | Michael Nolan <htfoot(at)gmail(dot)com> |
| Cc: | Thom Brown <thom(at)linux(dot)com>, PostgreSQL-development <pgsql-hackers(at)postgresql(dot)org> |
| Subject: | Re: Slow temporary tables when using sync rep |
| Date: | 2012-04-17 10:30:03 |
| Message-ID: | 4F8D462B.4080809@enterprisedb.com |
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| Thread: | |
| Lists: | pgsql-hackers |
On 17.04.2012 02:54, Michael Nolan wrote:
> On Mon, Apr 16, 2012 at 6:27 PM, Thom Brown<thom(at)linux(dot)com> wrote:
>
>> Hi,
>>
>> I've noticed that when using synchronous replication (on 9.2devel at
>> least), temporary tables become really slow:
>
> Since temporary tables are only present until the session ends (or
> possibly only until a commit), why are they replicated at all?
They're not replicated.
What happens is that we write the commit record if the transaction
accesses a temporary table, but we don't flush it. However, we still
wait until it's replicated to the standby. The obvious fix is to not
wait for that, see attached.
--
Heikki Linnakangas
EnterpriseDB http://www.enterprisedb.com
| Attachment | Content-Type | Size |
|---|---|---|
| temp-rel-syncrep-flush-1.patch | text/x-diff | 575 bytes |
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