[Pgpool-general] Update query & PgPool Cache ?

[Yoshiyuki Asaba]

Hi,

From: "Richard MICHALOWICZ" <richard.michalowicz at mairie-poitiers.fr>
Subject: [Pgpool-general] Update query & PgPool Cache ?
Date: Tue, 11 Sep 2007 11:58:45 +0200

> The cache is used and i saw the table associated to the query cache filling
> with my requests and hash of them.
> 
>  
> 
> But in my different tries for query cache, the cache doesn't update itself
> when an Update Query passedU.
> 
> So when i try this scenario passing by Pgpool:
> 
> 1)Select ...   (3 results)
> 
> 2)Update .    (1 result updated)
> 
> 3)Select ..    (3 results not updated)
> 
>  
> 
> Im using an PostgreSQL server 8.1.8 and Pgpool-II 1.2.
> 
>  
> 
> What is the policy for the pgpool cache ?

pgpool has a limitation of query cache.

  Currently, query cache must be deleted manually. pgpool-II does not
  invalidate old query cache automatically when the data is updated.

pgpool register query cache on system DB. If you invalidate it,
you truncate "pgpool.query_cache" table on system DB.

We considered auto-cache-invalidation mechanism. However, we could not
find a good solution...

If someone have a idea for cache invalidation, please discuss it.
Comments are welcome.
--
Yoshiyuki Asaba
y-asaba at sraoss.co.jp