Re: Re: [COMMITTERS] pgsql: Compress GIN posting lists, for smaller index size.

On 01/23/2014 10:37 PM, Tom Lane wrote:
> Heikki Linnakangas <hlinnakangas(at)vmware(dot)com> writes:
>> On 01/23/2014 09:18 PM, Stefan Kaltenbrunner wrote:
>>> it seems that this commit made spoonbill an unhappy animal:
>>> http://www.pgbuildfarm.org/cgi-bin/show_log.pl?nm=spoonbill&dt=2014-01-23%2000%3A00%3A04
>
>> Hmm, all the Sparcs. Some kind of an alignment issue, perhaps? I will
>> investigate..
>
> My HPUX box, which is also picky about alignment, is unhappy as well.
> It's crashing here:
>
> ginPostingListDecode (plist=0xc39efac1, ndecoded=0x7b03bee0)
> at ginpostinglist.c:263
> 263 return ginPostingListDecodeAllSegments(plist,
> (gdb) bt
> #0 ginPostingListDecode (plist=0xc39efac1, ndecoded=0x7b03bee0)
> at ginpostinglist.c:263
> #1 0x205308 in ginReadTuple (ginstate=0xc39efac1, attnum=48864,
> itup=0x7b03bee0, nitems=0x403ee9a4) at ginentrypage.c:170
> #2 0x21074c in startScanEntry (ginstate=0x403ec3ac, entry=0x403ee970)
> at ginget.c:463
> #3 0x21086c in startScan (scan=0xc39efac1) at ginget.c:493
> #4 0x212c14 in gingetbitmap (fcinfo=0xc39efac1) at ginget.c:1531
> #5 0x5ffc50 in FunctionCall2Coll (flinfo=0xc39efac1, collation=2063843040,
> arg1=2063843040, arg2=1077864868) at fmgr.c:1323
> #6 0x24ee5c in index_getbitmap (scan=0x40163878, bitmap=0x403ee620)
> at indexam.c:649
> #7 0x3b9430 in MultiExecBitmapIndexScan (node=0x40163768)
> at nodeBitmapIndexscan.c:89
> #8 0x3a5a3c in MultiExecProcNode (node=0x40163768) at execProcnode.c:562
> #9 0x3b8610 in BitmapHeapNext (node=0x401628f0) at nodeBitmapHeapscan.c:104
> #10 0x3ae5b0 in ExecScan (node=0x401628f0,
> accessMtd=0x4001a2c2 <DINFINITY+3802>,
> recheckMtd=0x4001a2ca <DINFINITY+3810>) at execScan.c:82
> #11 0x3b8e9c in ExecBitmapHeapScan (node=0xc39efac1)
> at nodeBitmapHeapscan.c:441
> #12 0x3a56e0 in ExecProcNode (node=0x401628f0) at execProcnode.c:414
> ...
>
> (gdb) p debug_query_string
> $1 = 0x4006d4a8 "SELECT * FROM array_index_op_test WHERE i <@ '{38,34,32,89}' ORDER BY seqno;"
>
> The problem appears to be due to the misaligned "plist" pointer
> (0xc39efac1 here).

Ah, thanks! Looks like I removed a SHORTALIGN from ginFormTuple that was
in fact very much necessary.. Fixed now, let's see if that pacifies the
sparcs.

- Heikki