Horton

Re: [HACKERS] [WIP] Effective storage of duplicates in B-tree index.

Fujii Masao <masao.fujii@oss.nttdata.com>

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From: Fujii Masao <masao.fujii@oss.nttdata.com>
To: Peter Geoghegan <pg@bowt.ie>, Anastasia Lubennikova <a.lubennikova@postgrespro.ru>
Cc: Heikki Linnakangas <hlinnaka@iki.fi>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>, Юрий Соколов <funny.falcon@gmail.com>
Date: 2020-02-27T06:03:07Z
Lists: pgsql-hackers 

On 2020/02/27 7:43, Peter Geoghegan wrote:
> On Mon, Feb 24, 2020 at 4:54 PM Peter Geoghegan <pg@bowt.ie> wrote:
>> Attached is v34, which has this change. My plan is to commit something
>> very close to this on Wednesday morning (barring any objections).
> 
> Pushed.

Thanks for committing this nice feature!

Here is one minor comment.

+      <primary><varname>deduplicate_items</varname></primary>
+      <secondary>storage parameter</secondary>

This should be

     <primary><varname>deduplicate_items</varname> storage parameter</primary>

<secondary> for reloption is necessary only when the GUC parameter
with the same name of the reloption exists. So, for example, you can
see that <secondary> is used in vacuum_cleanup_index_scale_factor
but not in buffering reloption.

Regards,

-- 
Fujii Masao
NTT DATA CORPORATION
Advanced Platform Technology Group
Research and Development Headquarters

Commits

  1. Teach pageinspect about nbtree deduplication.

  2. Doc: Fix deduplicate_items index term.

  3. Revise BTP_HAS_GARBAGE nbtree VACUUM comments.

  4. Remove unneeded "pin scan" nbtree VACUUM code.

  5. Cleanup code in reloptions.h regarding reloption handling

  6. Catch invalid typlens in a couple of places

  7. Compute XID horizon for page level index vacuum on primary.

  8. Make heap TID a tiebreaker nbtree index column.

  9. Avoid pin scan for replay of XLOG_BTREE_VACUUM in all cases

  10. Revert buggy optimization of index scans

  11. Restructure index access method API to hide most of it at the C level.

  12. Reduce pinning and buffer content locking for btree scans.

  13. Avoid scanning nulls at the beginning of a btree index scan.