Re: Parallel Bitmap scans a bit broken

Dilip Kumar <dilipbalaut@gmail.com>

From: Dilip Kumar <dilipbalaut@gmail.com>
To: David Rowley <david.rowley@2ndquadrant.com>
Cc: PostgreSQL-development <pgsql-hackers@postgresql.org>, Robert Haas <robertmhaas@gmail.com>
Date: 2017-03-09T16:32:12Z
Lists: pgsql-hackers

Attachments

On Thu, Mar 9, 2017 at 9:37 PM, Dilip Kumar <dilipbalaut@gmail.com> wrote:
>> =# create table r1(value int);
>> CREATE TABLE
>> =# insert into r1 select (random()*1000)::int from
>> generate_Series(1,1000000);
>> INSERT 0 1000000
>> =# create index on r1 using brin(value);
>> CREATE INDEX
>> =# set enable_seqscan=0;
>> SET
>> =# explain select * from r1 where value=555;
>
> I am looking into the issue, I have already reproduced it.  I will
> update on this soon.
>
> Thanks for reporting.

I slightly modified your query to reproduce this issue.

explain analyze select * from r1 where value<555;

Patch is attached to fix the problem.

-- 
Regards,
Dilip Kumar
EnterpriseDB: http://www.enterprisedb.com

Commits

  1. Avoid access to uninitialized memory in shared tidbitmap iteration.

  2. Bump catversion for MACADDR8

  3. Fix bug in parallel tidbitmap iteration.