Re: SetBufferCommitInfoNeedsSave and race conditions - Mailing list pgsql-hackers

From Simon Riggs
Subject Re: SetBufferCommitInfoNeedsSave and race conditions
Date
Msg-id 1183068576.3589.5.camel@silverbirch.site
Whole thread Raw
In response to Re: SetBufferCommitInfoNeedsSave and race conditions  (Tom Lane <tgl@sss.pgh.pa.us>)
Responses Re: SetBufferCommitInfoNeedsSave and race conditions  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-hackers
On Thu, 2007-06-28 at 15:16 -0400, Tom Lane wrote:
> Heikki Linnakangas <heikki@enterprisedb.com> writes:
> > AFAICS, we can just simply remove the assertion. But is there any 
> > codepaths that assume that after calling HeapTupleSatisfiesSnapshot, all 
> > appropriate hint bits are set?
> 
> There had better not be, since we are going to postpone setting hint
> bits for recently-committed transactions as part of the async-commit
> patch.
> 
> A quick grep suggests that VACUUM FULL might be at risk here.

No we're clear: I caught that issue specifically for VACUUM FULL fairly
early on. VF assumes all hint bits are set after the first scan, so we
flush prior to the scan to ensure its safe to set the hint bits. There
are no concurrent hint bit setters, so we are good.

--  Simon Riggs              EnterpriseDB   http://www.enterprisedb.com




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