Re: partitioning and locking problems - Mailing list pgsql-performance

From Markus Schaber
Subject Re: partitioning and locking problems
Date
Msg-id 43E1FEA7.8060509@logix-tt.com
Whole thread Raw
In response to partitioning and locking problems  ("Marc Morin" <marc@sandvine.com>)
List pgsql-performance
Hi, Marc,

Marc Morin wrote:

>     1- long running report is running on view
>     2- continuous inserters into view into a table via a rule
>     3- truncate or rule change occurs, taking an exclusive lock.
> Must wait for #1 to finish.
>     4- new reports and inserters must now wait for #3.
>     5- now everyone is waiting for a single query in #1.   Results
> in loss of insert data granularity (important for our application).

Apart from having two separate views (one for report, one for insert) as
Richard suggested:

If you have fixed times for #3, don't start any #1 that won't finish
before it's time for #3.

You could also use the LOCK command on an empty lock table at the
beginning of each #1 or #3 transaction to prevent #3 from getting the
view lock before #1 is finished.


HTH,
Markus

--
Markus Schaber | Logical Tracking&Tracing International AG
Dipl. Inf.     | Software Development GIS

Fight against software patents in EU! www.ffii.org www.nosoftwarepatents.org

pgsql-performance by date:

Previous
From: Markus Schaber
Date:
Subject: Re: Where is my bottleneck?
Next
From: "Marc Morin"
Date:
Subject: Re: partitioning and locking problems