Re: [HACKERS] Parallel Bitmap scans a bit broken - Mailing list pgsql-hackers

From Emre Hasegeli
Subject Re: [HACKERS] Parallel Bitmap scans a bit broken
Date
Msg-id CAE2gYzwvsZ1xmUHJ+YsaLaae+rf_Fu1G7yDtGStYfbqr_7tRFQ@mail.gmail.com
Whole thread Raw
In response to Re: [HACKERS] Parallel Bitmap scans a bit broken  (Dilip Kumar <dilipbalaut@gmail.com>)
Responses Re: [HACKERS] Parallel Bitmap scans a bit broken  (Dilip Kumar <dilipbalaut@gmail.com>)
List pgsql-hackers
> With my test case, I could not crash even with this patch applied.
> Can you provide your test case?

Yes:

> hasegeli=# create table r2 as select (random() * 3)::int as i from generate_series(1, 1000000);
> SELECT 1000000
> hasegeli=# create index on r2 using brin (i);
> CREATE INDEX
> hasegeli=# analyze r2;
> ANALYZE
> hasegeli=# explain select * from only r2 where i = 10;
>                                      QUERY PLAN
> -------------------------------------------------------------------------------------
>  Gather  (cost=2867.50..9225.32 rows=1 width=4)
>    Workers Planned: 2
>    ->  Parallel Bitmap Heap Scan on r2  (cost=1867.50..8225.22 rows=1 width=4)
>          Recheck Cond: (i = 10)
>          ->  Bitmap Index Scan on r2_i_idx  (cost=0.00..1867.50 rows=371082 width=0)
>                Index Cond: (i = 10)
> (6 rows)
>
> hasegeli=# select * from only r2 where i = 10;
> server closed the connection unexpectedly
> This probably means the server terminated abnormally
> before or while processing the request.
> The connection to the server was lost. Attempting reset: Failed.



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