Re: assessing parallel-safety

On Fri, Mar 20, 2015 at 7:54 PM, Thom Brown <thom@linux.com> wrote:

> createdb pgbench
> pgbench -i -s 200 pgbench
>
> CREATE TABLE pgbench_accounts_1 (CHECK (bid = 1)) INHERITS (pgbench_accounts);
> ...
> CREATE TABLE pgbench_accounts_200 (CHECK (bid = 200)) INHERITS
> (pgbench_accounts);
>

I managed to reproduce the Assertion reported by you as:

#2  0x00000000007a053a in ExceptionalCondition (conditionName=conditionName@entry=0x813a4b "!(IsInParallelMode())", errorType=errorType@entry=0x7da1d6 "FailedAssertion", fileName=fileName@entry=0x81397d "parallel.c", lineNumber=lineNumber@entry=123) at assert.c:54
#3  0x00000000004cd5ba in CreateParallelContext (entrypoint=entrypoint@entry=0x659d2c <ParallelQueryMain>, nworkers=nworkers@entry=8) at parallel.c:123

The reason is that CreateParallelContext() expects to be called

in ParallelMode and we enter into parallel-mode after InitPlan()

in standard_ExecutorStart().  So the probable fix could be

to EnterParallelMode before initializing the plan.

I still could not reproduce the crash you have reported as:

>> #0  0x0000000000770843 in pfree ()
>> #1  0x00000000005a382f in ExecEndFunnel ()
>> #2  0x000000000059fe75 in ExecEndAppend ()
>> #3  0x00000000005920bd in standard_ExecutorEnd ()

Could you let me know which all patches you have tried

and on top of which commit.

I am trying on the commit as mentioned in mail[1]. Basically

have you tried the versions mentioned in that mail:

HEAD Commit-id : 8d1f2390
parallel-mode-v8.1.patch [2]
assess-parallel-safety-v4.patch [1]
parallel-heap-scan.patch [3]
parallel_seqscan_v11.patch (Attached with this mail)

If something else, could you let me know the same so that I can try

that to reproduce the issue reported by you.