Re: Instead of using the bloom index, a parallel sequencial scan isused with this example - Mailing list pgsql-docs

From Daniel Westermann (DWE)
Subject Re: Instead of using the bloom index, a parallel sequencial scan isused with this example
Date
Msg-id VI1PR09MB4142FC41A11AE3FFAA52B1F9D27E0@VI1PR09MB4142.eurprd09.prod.outlook.com
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In response to Re: Instead of using the bloom index, a parallel sequencial scan isused with this example  (Bruce Momjian <bruce@momjian.us>)
Responses Re: Instead of using the bloom index, a parallel sequencial scan isused with this example  (Bruce Momjian <bruce@momjian.us>)
List pgsql-docs

>>On Thu, Oct 24, 2019 at 03:17:06PM +0000, PG Doc comments form wrote:
>> The following documentation comment has been logged on the website:
>>
>>Page: https://www.postgresql.org/docs/12/bloom.html
>> Description:

>I cleaned up your script and created an SQL file that can be piped into
>psql, attached.  I see the bloomidx index being used without and with
>the ANALYZE, output attached.  I tested this on git master, and back
>through PG 10.  Would you please run these queries and post the output:

Thanks for having a look, Bruce. You test case is not exactly the same as in the documentation. For you "temporary table" test case I indeed see the bloom index getting used. Doing the same with a normal table results in a parallel seq scan.

postgres=# SELECT version();
                                                          version                                                          
----------------------------------------------------------------------------------------------------------------------------
 PostgreSQL 12.0  on x86_64-pc-linux-gnu, compiled by gcc (GCC) 4.8.5 20150623 (Red Hat 4.8.5-39), 64-bit
(1 row)

postgres=# SELECT name, current_setting(name), source
postgres-#         FROM pg_settings
postgres-#         WHERE source NOT IN ('default', 'override');
            name            |  current_setting   |                      
----------------------------+--------------------+----------------------
 application_name           | psql               | client
 client_encoding            | UTF8               | client
 DateStyle                  | ISO, MDY           | configuration file
 default_text_search_config | pg_catalog.english | configuration file
 dynamic_shared_memory_type | posix              | configuration file
 lc_messages                | en_US.utf8         | configuration file
 lc_monetary                | de_CH.UTF-8        | configuration file
 lc_numeric                 | de_CH.UTF-8        | configuration file
 lc_time                    | en_US.UTF-8        | configuration file
 listen_addresses           | *                  | configuration file
 log_timezone               | Europe/Zurich      | configuration file
 max_connections            | 100                | configuration file
 max_stack_depth            | 2MB                | environment variable
 max_wal_size               | 1GB                | configuration file
 min_wal_size               | 80MB               | configuration file
 port                       | 5432               | environment variable
 shared_buffers             | 128MB              | configuration file
 TimeZone                   | Europe/Zurich      | configuration file

Regards
Daniel
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