[pgpool-general: 8224] Re: Cache_unsafe_memqcache_table_list not working on reload

Tatsuo Ishii ishii at sraoss.co.jp
Fri Jun 17 09:30:18 JST 2022

> Hi,
> I did the following:
> 1. Select * from city limit 1;
> 2. Add city to unsafe configuration.
> 3. Reload pgpool.
> 4. Select * from city limit 1; # return from the cache.
> I expected that pgpool after adding the table to the unsafe will not return
> the same query from the cache.
> I check the code and I saw that pgpool not check if the query is from table
> which included in the unsafe configuration. Means pgpool check only in
> store and not in fetch.
> Any thoughts? This is a bug?

It's intended. Fetching cache should be as fast as possible, because
slow query cache is meaningless (users want to use query cache to
speed up their queries). Checking cache_unsafeness is an expensive
operation: it requires parsing SQL and sending queries PostgreSQL's
system catalog.

Best reagards,
Tatsuo Ishii
SRA OSS, Inc. Japan
English: http://www.sraoss.co.jp/index_en.php

More information about the pgpool-general mailing list