Horton

Re: ALTER TABLE lock strength reduction patch is unsafe

Noah Misch <noah@leadboat.com>

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From: Noah Misch <noah@leadboat.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Robert Haas <robertmhaas@gmail.com>, Simon Riggs <simon@2ndquadrant.com>, Bruce Momjian <bruce@momjian.us>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2011-12-20T16:23:02Z
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 →

  1. Add bytea_agg, parallel to string_agg.

  2. Fix ALTER TABLE ONLY .. DROP CONSTRAINT.

On Mon, Dec 19, 2011 at 11:13:57PM -0500, Tom Lane wrote:
> Noah Misch <noah@leadboat.com> writes:
> > I created a function that does this in a loop:
> 
> > 		HeapTuple t;
> 
> > 		CatalogCacheFlushCatalog(ProcedureRelationId);
> > 		t = SearchSysCache1(PROCOID, ObjectIdGetDatum(42) /* int4in */);
> > 		if (!HeapTupleIsValid(t))
> > 			elog(ERROR, "cache lookup failed for function 42");
> > 		ReleaseSysCache(t);
> 
> ... but this performance test seems to me to be entirely misguided,
> because it's testing a situation that isn't going to occur much in the
> field, precisely because the syscache should prevent constant reloads of
> the same syscache entry.

> [ideas for more-realistic tests]

Granted, but I don't hope to reliably measure a change in a macro-benchmark
after seeing a rickety 2% change in a micro-benchmark.