Re: SSI patch version 14 - Mailing list pgsql-hackers

From Kevin Grittner
Subject Re: SSI patch version 14
Date
Msg-id 4D52655A020000250003A6D7@gw.wicourts.gov
Whole thread Raw
In response to Re: SSI patch version 14  (Dan Ports <drkp@csail.mit.edu>)
Responses Re: SSI patch version 14  (Heikki Linnakangas <heikki.linnakangas@enterprisedb.com>)
List pgsql-hackers
Dan Ports <drkp@csail.mit.edu> wrote:

> I think for SerializableXidHash we should probably just initially
> allocate it at its maximum size. Then it'll match the PredXact
> list which is allocated in full upfront, and there's no risk of
> being able to allocate a transaction but not register its xid. In
> fact, I believe there would be no way for starting a new
> serializable transaction to fail.

To be more precise, it would prevent an out of shared memory error
during an attempt to register an xid for an active serializable
transaction.  That seems like a good thing.  Patch to remove the
hint and initially allocate that HTAB at full size attached.

I didn't attempt to address the larger general issue of one HTAB
stealing shared memory from space calculated to belong to another,
and then holding on to it until the postmaster is shut down.

-Kevin

Attachment

pgsql-hackers by date:

Previous
From: Markus Wanner
Date:
Subject: Re: SSI patch version 14
Next
From: David Fetter
Date:
Subject: Re: [COMMITTERS] pgsql: Remove more SGML tabs.