Re: Fwd: How does the partitioned lock manager works? - Mailing list pgsql-hackers

From Alvaro Herrera
Subject Re: Fwd: How does the partitioned lock manager works?
Date
Msg-id 20070427135524.GF4645@alvh.no-ip.org
Whole thread Raw
In response to Fwd: How does the partitioned lock manager works?  ("rancpine cui" <rancpine@gmail.com>)
Responses Re: Fwd: How does the partitioned lock manager works?  (Tom Lane <tgl@sss.pgh.pa.us>)
Re: Fwd: How does the partitioned lock manager works?  ("rancpine cui" <rancpine@gmail.com>)
List pgsql-hackers
rancpine cui escribió:

> I've seen from the README that
> "The shared-memory hash tables for LOCKs and PROCLOCKs are organized
> so that different partitions use different hash chains, and thus there
> is no conflict in working with objects in different partitions."
>   What does "hash chains" mean?

Each "hash chain" is a different, separate, independent hash struct.

>   As the dynahash.c's "partitioned table" mechanism suggests, a lock's
> bucket number can be calculated from its hash value, then it will be
> inserted into that bucket,so how does partition number works?

Which hash is used depends on the partition number.

-- 
Alvaro Herrera                                http://www.CommandPrompt.com/
PostgreSQL Replication, Consulting, Custom Development, 24x7 support


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