Re: transaction timeout - Mailing list pgsql-general

From Dr NoName
Subject Re: transaction timeout
Date
Msg-id 20050726175116.11807.qmail@web31503.mail.mud.yahoo.com
Whole thread Raw
In response to transaction timeout  (Dr NoName <spamacct11@yahoo.com>)
Responses Re: transaction timeout
List pgsql-general
> If you have second database in the cluster is it
> still operational when
> the main database locks up?

we don't have a DB cluster. It would be pretty useless
since postgresql doesn't support distributed
transactions.

> Also it seems that some diagnostics are needed in
> the client app to log
> the crash event so you can determine which SQL
> commands are causing the
> lock.

I'll try to get that next time it happens. But
regardless of sql commands are running, I know what
the root cause is: a client hangs while in
transaction.

> Despite many years of writing buggy code I have not
> yet locked a whole
> DB in the fashion described. I can not see how a
> simple select / insert
> / update command sequence can achieve it unless
> there is a particular
> relation between the tables involved.

As I have already said, I suspect this might be caused
by a combination of an open transaction and a weekly
VACUUM FULL. Does that sound right?

> If the tables are related / linked via rules /
> triggers/ keys then
> perhaps add a test table that bears no relation to
> the others and see if
> it is locked when the others appear to have this
> problem you are describing.
>
> Perhaps a simple test : When the DB error occurs can
> you use PGAdmin to
> read an independent table, or read from another
> database.

thanks, I'll try that.

Eugene




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