Re: Vacuum: allow usage of more than 1GB of work mem

Anastasia Lubennikova <a.lubennikova@postgrespro.ru>

From: Anastasia Lubennikova <a.lubennikova@postgrespro.ru>
To: Alvaro Herrera <alvherre@2ndquadrant.com>
Cc: Claudio Freire <klaussfreire@gmail.com>, Anastasia Lubennikova <lubennikovaav@gmail.com>, PostgreSQL-Dev <pgsql-hackers@postgresql.org>
Date: 2016-12-28T12:37:04Z
Lists: pgsql-hackers
27.12.2016 16:54, Alvaro Herrera:
> Anastasia Lubennikova wrote:
>
>> I ran configure using following set of flags:
>>   ./configure --enable-tap-tests --enable-cassert --enable-debug
>> --enable-depend CFLAGS="-O0 -g3 -fno-omit-frame-pointer"
>> And then ran make check. Here is the stacktrace:
>>
>> Program terminated with signal SIGSEGV, Segmentation fault.
>> #0  0x00000000006941e7 in lazy_vacuum_heap (onerel=0x1ec2360,
>> vacrelstats=0x1ef6e00) at vacuumlazy.c:1417
>> 1417                tblk =
>> ItemPointerGetBlockNumber(&seg->dead_tuples[tupindex]);
> This doesn't make sense, since the patch removes the "tupindex"
> variable in that function.
>

Sorry, I didn't get what you mean.

In  0002-Vacuum-allow-using-more-than-1GB-work-mem-v3.patch

-    tupindex = 0;
-    while (tupindex < vacrelstats->num_dead_tuples)
+    segindex = 0;
+    tottuples = 0;
+    for (segindex = 0; segindex <= vacrelstats->dead_tuples.last_seg; 
tupindex = 0, segindex++)
      {

variable is still there, it was just moved to the loop.

-- 
Anastasia Lubennikova
Postgres Professional: http://www.postgrespro.com
The Russian Postgres Company



Commits

  1. Prefetch blocks during lazy vacuum's truncation scan

  2. Explain unaccounted for space in pgstattuple.