Re: [HACKERS] Microvacuum support for Hash Index

Hi Ashutosh,

On 01/04/2017 06:13 AM, Ashutosh Sharma wrote:
> Attached is the v3 patch rebased on postgreSQL HEAD and WAL v7 patch.
> It also takes care of all the previous comments from Jesper - [1].
>

With an --enable-cassert build (master / WAL v7 / MV v3) and

-- ddl.sql --
CREATE TABLE test AS SELECT generate_series(1, 10) AS id, 0 AS val;
CREATE INDEX IF NOT EXISTS idx_id ON test USING hash (id);
CREATE INDEX IF NOT EXISTS idx_val ON test USING hash (val);
ANALYZE;
-- ddl.sql --

-- test.sql --
\set id random(1,10)
\set val random(0,10)
BEGIN;
UPDATE test SET val = :val WHERE id = :id;
COMMIT;
-- test.sql --

using pgbench -M prepared -c 10 -j 10 -T 600 -f test.sql test

crashes after a few minutes with

TRAP: FailedAssertion("!(LWLockHeldByMeInMode(((LWLock*) 
(&(bufHdr)->content_lock)), LW_EXCLUSIVE))", File: "bufmgr.c", Line: 3781)

BTW, better rename 'hashkillitems' to '_hash_kill_items' to follow the 
naming convention in hash.h

Best regards, Jesper