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Re: GIN improvements part 1: additional information - Mailing list pgsql-hackers

From Alexander Korotkov
Subject Re: GIN improvements part 1: additional information
Date
Msg-id CAPpHfdvbmTrnPg2f6S_E2k2JVmHFipSJPG_ooDHKFbwi4oKfOw@mail.gmail.com
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In response to Re: GIN improvements part 1: additional information  (Alexander Korotkov <aekorotkov@gmail.com>)
Responses Re: GIN improvements part 1: additional information
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On Mon, Sep 23, 2013 at 12:47 AM, Alexander Korotkov <aekorotkov@gmail.com> wrote:
It's probably an option to select 64 entries instead of 32.
There is still some regression in update speed. However, there is also room for improvement patch. It searches item index entries 2 times on insert: in dataLocateLeafItem and dataPlaceToPage. We can save full results of dataLocateLeafItem, but it require some rework of gin btree interface: store not only offset of item.

In the attached version of patch double finding of ItemPointer during insert is avoided. Overhead becomes lower as expected.

         event         |    master       |  16-entries     |  32-entries     |  64-entries     |  128-entries    |
-----------------------+-----------------+-----------------+-----------------+-----------------+-----------------+
 index_build           | 00:01:50.042658 | 00:01:54.130873 | 00:01:59.37302  | 00:01:55.959693 | 00:01:58.126407 |
 index_build_recovery  | 00:00:19        | 00:00:06        | 00:00:06        | 00:00:06        | 00:00:06        |
 index_update          | 00:05:18.215707 | 00:05:38.40231  | 00:05:30.658786 | 00:05:27.664312 | 00:05:30.815876 |
 index_update_recovery | 00:01:48        | 00:01:53        | 00:01:50        | 00:01:44        | 00:01:46        |
 search_new            | 00:25:21.481699 | 00:23:20.324152 | 00:24:02.120438 | 00:22:50.989723 | 00:23:05.703824 |
 search_updated        | 00:25:57.622592 | 00:26:43.531979 | 00:26:08.003085 | 00:24:36.669028 | 00:26:09.175243 |


     label     |    size    | 16-entries | 32-entries | 64-entries | 128-entries |
---------------+------------+------------+------------+------------+-------------+
 new           |  884514816 |  417013760 |  421240832 |  430350336 |   450994176 |
 after_updates | 1595252736 |  711368704 |  719380480 |  735682560 |   774275072 |

------
With best regards,
Alexander Korotkov.
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