Re: BUG #14344: string_agg(DISTINCT ..) crash

On Wed, Sep 28, 2016 at 9:23 PM, Michael Paquier <michael(dot)paquier(at)gmail(dot)com>
wrote:
> On Wed, Sep 28, 2016 at 9:10 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>> lr(at)pcorp(dot)us writes:
>>> Let me know if you need more info or if this has already been fixed.
>> regression=# SELECT string_agg(DISTINCT state, ',' ORDER BY state)
>> FROM string_agg_crash_test;
>> string_agg
>> -------------------
>> HI,IL,KS,MA,MA,NY
>> (1 row)
>>
>> But I see no post-rc1 fixes that look like they might explain this.
>
> No problems on OSX or Linux, but I am getting a crash on Windows
> (Win7, MSVC 2010) even with latest REL9_6_STABLE. Oops.

After rolling in crashdumps/ and remembering some stuff about windbg:
- .sympath to point to symbols
- !analyze -v to load the backtrace:
00000000`0042eff0 00000001`40380293 : 000007fe`fda07a01 000007fe`fda07a11
00000000`ffff0000 00000000`000004e4 : postgres!toast_raw_datum_size+0x4
[c:\users\ioltas\git\postgres\src\backend\access\heap\tuptoaster.c @ 358]
00000000`0042f030 00000001`403ab6dc : 00000000`009f0000 00000000`00000002
00000000`008491f8 00000000`008f3caa : postgres!texteq+0x33
[c:\users\ioltas\git\postgres\src\backend\utils\adt\varlena.c @ 1616]
00000000`0042f060 00000001`4012a29e : 00000000`00000002 00000000`008491f8
00000000`008f3caa 00000000`00000001 : postgres!FunctionCall2Coll+0x5c
[c:\users\ioltas\git\postgres\src\backend\utils\fmgr\fmgr.c @ 1322]
00000000`0042f450 00000001`4013d05c : 00000000`00000002 00000000`01b33b30
00000000`008f3b00 00000000`008f3830 : postgres!execTuplesMatch+0xae
[c:\users\ioltas\git\postgres\src\backend\executor\execgrouping.c @ 101]
00000000`0042f4a0 00000001`4013d61c : 00000000`00895f00 00000000`00000000
00000000`01b359d8 00000000`00849308 :
postgres!process_ordered_aggregate_multi+0xfc
[c:\users\ioltas\git\postgres\src\backend\executor\nodeagg.c @ 1248]
00000000`0042f520 00000001`4013f081 : 00000000`00000001 00000000`00000000
00000000`01b33f98 00000000`00000000 : postgres!finalize_aggregates+0x9c
[c:\users\ioltas\git\postgres\src\backend\executor\nodeagg.c @ 1557]
00000000`0042f580 00000001`4013fe9a : 00000000`008ee800 00000000`00000003
00000000`01b33ee8 00000000`01b33f98 : postgres!agg_retrieve_direct+0x461
[c:\users\ioltas\git\postgres\src\backend\executor\nodeagg.c @ 2163]
00000000`0042f620 00000001`40130352 : 00000000`00000054 00000001`4029eaea
00000000`00000000 00000000`00000001 : postgres!ExecAgg+0x4a
[c:\users\ioltas\git\postgres\src\backend\executor\nodeagg.c @ 1838]
00000000`0042f650 00000001`4012c98d : 00000000`01b33a20 00000001`4000a42c
00000000`ffffffff 00000000`00000001 : postgres!ExecProcNode+0x202
[c:\users\ioltas\git\postgres\src\backend\executor\execprocnode.c @ 503]
00000000`0042f680 00000001`4012dc58 : 00000000`008d9b60 00000000`00000001
00000000`01b33a20 00000000`00000000 : postgres!ExecutePlan+0x7d
[c:\users\ioltas\git\postgres\src\backend\executor\execmain.c @ 1573]
00000000`0042f6d0 00000001`4029f659 : 00000000`008df510 00000000`00000000
00000000`008df510 00000001`403cb144 : postgres!standard_ExecutorRun+0xb8
[c:\users\ioltas\git\postgres\src\backend\executor\execmain.c @ 350]
00000000`0042f740 00000001`4029fe6a : 00000000`008df510 00000000`008df510
00000000`00843d50 00000000`0042f8b0 : postgres!PortalRunSelect+0x99
[c:\users\ioltas\git\postgres\src\backend\tcop\pquery.c @ 949]
00000000`0042f7a0 00000001`4029d723 : 00000000`00000000 00000000`00843d50
00000000`00000000 00000000`00000000 : postgres!PortalRun+0x1ca
[c:\users\ioltas\git\postgres\src\backend\tcop\pquery.c @ 796]
00000000`0042f980 00000001`4029e1fc : 00000000`00000051 00000000`00894e60
00000000`0042fb70 00000000`009f8220 : postgres!exec_simple_query+0x573
[c:\users\ioltas\git\postgres\src\backend\tcop\postgres.c @ 1101]
00000000`0042fa70 00000001`4022eaea : 00000001`405f4300 00000001`404a37b8
00000000`000010a6 00000001`404a3938 : postgres!PostgresMain+0x63c
[c:\users\ioltas\git\postgres\src\backend\tcop\postgres.c @ 4072]
00000000`0042fc60 00000001`40232645 : 00000001`00000001 00000000`000861df
00000000`1f7f5412 00000000`00000000 : postgres!BackendRun+0x1ca
[c:\users\ioltas\git\postgres\src\backend\postmaster\postmaster.c @ 4271]
00000000`0042fcc0 00000001`4016ca71 : 00000000`00000003 00000000`009f2329
00000000`00000003 00000000`00000000 : postgres!SubPostmasterMain+0x255
[c:\users\ioltas\git\postgres\src\backend\postmaster\postmaster.c @ 4762]
00000000`0042ff00 00000001`403f1bfa : 00000000`00000000 00000000`00000001
00000000`00000000 00000000`00000000 : postgres!main+0x3c1
[c:\users\ioltas\git\postgres\src\backend\main\main.c @ 216]
00000000`0042ff30 00000000`76cc59cd : 00000000`00000000 00000000`00000000
00000000`00000000 00000000`00000000 : postgres!__tmainCRTStartup+0x11a
[f:\dd\vctools\crt_bld\self_64_amd64\crt\src\crtexe.c @ 555]
00000000`0042ff60 00000000`76efa2e1 : 00000000`00000000 00000000`00000000
00000000`00000000 00000000`00000000 : kernel32!BaseThreadInitThunk+0xd
00000000`0042ff90 00000000`00000000 : 00000000`00000000 00000000`00000000
00000000`00000000 00000000`00000000 : ntdll!RtlUserThreadStart+0x21

STACK_COMMAND: ~0s; .ecxr ; kb

FAULTING_SOURCE_CODE:
354: {
355: struct varlena *attr = (struct varlena *)
DatumGetPointer(value);
356: Size result;
357:
> 358: if (VARATT_IS_EXTERNAL_ONDISK(attr))
359: {
360: /* va_rawsize is the size of the original datum --
including header */
361: struct varatt_external toast_pointer;
362:
363: VARATT_EXTERNAL_GET_POINTER(toast_pointer, attr);

--
Michael