Horton

Re: Bugs in TOAST handling, OID assignment and redo recovery

Tom Lane <tgl@sss.pgh.pa.us>

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From: Tom Lane <tgl@sss.pgh.pa.us>
To: Pavan Deolasee <pavan.deolasee@gmail.com>
Cc: Heikki Linnakangas <hlinnaka@iki.fi>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2018-04-11T14:50:47Z
Lists: pgsql-hackers 
Pavan Deolasee <pavan.deolasee@gmail.com> writes:
> Or may be we simply err on the side of caution and scan the toast table
> with SnapshotAny while looking for a duplicate? That might prevent us from
> reusing an OID for a known-dead tuple, but should save us a second index
> scan and still work.

+1.  We really don't want to expend two indexscans on this.

I was worried about changing the signature of GetNewOidWithIndex in
a back-patched fix, but after looking around I think that's probably
safe.  External callers really shouldn't be using anything lower-level
than GetNewOid.

			regards, tom lane

Commits

  1. Ignore nextOid when replaying an ONLINE checkpoint.

  2. Do not select new object OIDs that match recently-dead entries.