Re: ALTER TABLE lock strength reduction patch is unsafe

Robert Haas <robertmhaas@gmail.com>

From: Robert Haas <robertmhaas@gmail.com>

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

Cc: Simon Riggs <simon@2ndquadrant.com>, Noah Misch <noah@leadboat.com>, Bruce Momjian <bruce@momjian.us>, pgsql-hackers <pgsql-hackers@postgresql.org>

Date: 2012-01-03T18:33:42Z

Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

Add bytea_agg, parallel to string_agg.
- d5448c7d31b5 9.2.0 cited
Fix ALTER TABLE ONLY .. DROP CONSTRAINT.
- c0f03aae0469 9.2.0 cited

On Tue, Jan 3, 2012 at 1:24 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> Um ... you're supposing that only DDL uses SnapshotNow, which is wrong.
> I refer you to the parser, the planner, execution functions for arrays,
> records, enums, any sort of relcache reload, etc etc etc.  Yes, some
> of that is masked by backend-internal caching, some of the time, but
> it's folly to just assume that there are no SnapshotNow scans during
> normal queries.

Hmm.  That's unfortunate, because it seems difficult to construct a
test case that will exercise every feature in the system.

-- 
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
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