From: | Merlin Moncure <mmoncure(at)gmail(dot)com> |
---|---|
To: | Robert Haas <robertmhaas(at)gmail(dot)com> |
Cc: | Fujii Masao <masao(dot)fujii(at)gmail(dot)com>, pgsql-bugs(at)postgresql(dot)org, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
Subject: | Re: BUG #6222: Segmentation fault on unlogged table |
Date: | 2011-09-26 16:17:04 |
Message-ID: | CAHyXU0wYfbkYGJNONrA84Hqxqi=R-k_gW83WD6kuDRe3Y-nN-w@mail.gmail.com |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-bugs |
On Mon, Sep 26, 2011 at 11:08 AM, Robert Haas <robertmhaas(at)gmail(dot)com> wrote:
> On Mon, Sep 26, 2011 at 11:40 AM, Robert Haas <robertmhaas(at)gmail(dot)com> wrote:
>> To check my work, I did this:
>>
>> --- a/src/backend/executor/execQual.c
>> +++ b/src/backend/executor/execQual.c
>> @@ -5003,6 +5003,7 @@ ExecQual(List *qual, ExprContext *econtext, bool
>> resultForNull)
>> Datum expr_value;
>> bool isNull;
>>
>> + Assert(!IsA(clause, List));
>> expr_value = ExecEvalExpr(clause, econtext, &isNull, NULL);
>>
>> if (isNull)
>>
>> And in fact the test case (when run against the unlogged tables) fails
>> that assertion:
>>
>> TRAP: FailedAssertion("!(!((((Node*)(clause))->type) == T_List))",
>> File: "execQual.c", Line: 5006)
>>
>> Now I'm not too sure why that is happening yet, but I'm leaning toward
>> the idea that the bug here is timing-related and that unlogged tables
>> aren't the cause, but rather just make it easier to hit whatever the
>> race condition is by removing some overhead.
>
> I cannot reproduce this on commit
> e6faf910d75027bdce7cd0f2033db4e912592bcc. But on the very next commit
> I can:
>
> commit e6faf910d75027bdce7cd0f2033db4e912592bcc
> Author: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
> Date: Fri Sep 16 00:42:53 2011 -0400
>
> Redesign the plancache mechanism for more flexibility and efficiency.
>
> Tom, any thoughts?
hm. any relation to YAMAMOTO Takashi's recent email, [BUGS] bug in
plancache.c, which hasn't hit the archives yet?
> "GetCachedPlan can pass the 'qlist' to the planner twice.
if i understand the code correctly, it's unsafe because the planner is
destructive wrt the input tree. for my application, it often causes
a crash in executor."
merlin
From | Date | Subject | |
---|---|---|---|
Next Message | Robert Haas | 2011-09-26 16:20:22 | Re: BUG #6222: Segmentation fault on unlogged table |
Previous Message | Robert Haas | 2011-09-26 16:08:22 | Re: BUG #6222: Segmentation fault on unlogged table |