Re: PostgreSQL clustering VS MySQL clustering

Matt Clark wrote:

> Presumably it can't _ever_ know without being explicitly told, because
> even for a plain SELECT there might be triggers involved that update
> tables, or it might be a select of a stored proc, etc.  So in the
> general case, you can't assume that a select doesn't cause an update,
> and you can't be sure that the table list in an update is a complete
> list of the tables that might be updated.

Uhmmm no :) There is no such thing as a select trigger. The closest you
would get
is a function that is called via select which could be detected by
making sure
you are prepending with a BEGIN or START Transaction. Thus yes pgPool
can be made
to do this.

Sincerely,

Joshua D. Drake



>
>
>
> Tatsuo Ishii wrote:
>
>> Can I ask a question?
>>
>> Suppose table A gets updated on the master at time 00:00. Until 00:03
>> pgpool needs to send all queries regarding A to the master only. My
>> question is, how can pgpool know a query is related to A?
>> --
>> Tatsuo Ishii
>>
>>
>>
>
> ---------------------------(end of broadcast)---------------------------
> TIP 2: you can get off all lists at once with the unregister command
>    (send "unregister YourEmailAddressHere" to majordomo@postgresql.org)



--
Command Prompt, Inc., home of Mammoth PostgreSQL - S/ODBC and S/JDBC
Postgresql support, programming shared hosting and dedicated hosting.
+1-503-667-4564 - jd@commandprompt.com - http://www.commandprompt.com
PostgreSQL Replicator -- production quality replication for PostgreSQL