Commit 45e3d8ae authored by Bruce Momjian's avatar Bruce Momjian

doc: move hash info to new section and split out growth item

Reported-by: Amit Kapila
parent cef5dbbf
......@@ -49,14 +49,16 @@
<listitem>
<!--
Created from "Improve hash bucket split performance" item
Copied here from this commit:
Author: Robert Haas <rhaas@postgresql.org>
2017-04-03 [ea69a0dea] Expand hash indexes more gradually.
-->
<para>
<application>pg_upgrade</>-ed hash indexes from previous major Postgres versions must be rebuilt.
</para>
<para>
Major hash index performance improvements necessitated this requirement.
Major hash storage improvements necessitated this requirement.
</para>
</listitem>
......@@ -450,130 +452,148 @@ processes for non-parallel purposes.
<listitem>
<!--
Author: Robert Haas <rhaas@postgresql.org>
2017-03-14 [c11453ce0] hash: Add write-ahead logging support.
Author: Andrew Dunstan <andrew@dunslane.net>
2017-03-31 [e306df7f9] Full Text Search support for <type>JSON</> and <type>JSONB</>
-->
<para>
Add write-ahead logging support to hash indexes (Amit Kapila)
Add full text search support for <type>JSON</> and <type>JSONB</> (Dmitry Dolgov)
</para>
<para>
This makes hash indexes crash-safe and replicated, and removes the
warning message about their use.
This is accessed via <function>ts_headline()</> and to_tsvector. RIGHT SECTION?
</para>
</listitem>
<listitem>
<!--
Author: Robert Haas <rhaas@postgresql.org>
2016-11-30 [6d46f4783] Improve hash index bucket split behavior.
Author: Robert Haas <rhaas@postgresql.org>
2017-02-07 [293e24e50] Cache hash index's metapage in rel->rd_amcache.
Author: Robert Haas <rhaas@postgresql.org>
2017-02-27 [b0f18cb77] hash: Refactor bucket squeeze code.
Author: Robert Haas <rhaas@postgresql.org>
2017-02-27 [30df93f69] hash: Refactor overflow page allocation.
Author: Robert Haas <rhaas@postgresql.org>
2017-04-03 [ea69a0dea] Expand hash indexes more gradually.
Author: Tom Lane <tgl@sss.pgh.pa.us>
2016-08-23 [77e290682] Create an SP-GiST opclass for inet/cidr.
-->
<para>
Improve hash bucket split performance by reducing locking requirements
(Amit Kapila, Mithun Cy)
Add <acronym>SP-GiST</> index support for <type>INET</> and <type>CIDR</> data types (Emre Hasegeli)
</para>
<para>
Also cache hash index meta-information for faster lookups. Additional
hash performance improvements have also been made.
These data types already had GiST support.
</para>
</listitem>
<listitem>
<!--
Author: Robert Haas <rhaas@postgresql.org>
2017-03-15 [6977b8b7f] Port single-page btree vacuum logic to hash indexes.
Author: Teodor Sigaev <teodor@sigaev.ru>
2017-03-23 [218f51584] Reduce page locking in <acronym>GIN</> vacuum
-->
<para>
Allow single-page hash pruning (Ashutosh Sharma)
Reduce page locking during vacuuming of <acronym>GIN</> indexes (Andrey Borodin)
</para>
</listitem>
<listitem>
<!--
Author: Andrew Dunstan <andrew@dunslane.net>
2017-03-31 [e306df7f9] Full Text Search support for <type>JSON</> and <type>JSONB</>
Author: Alvaro Herrera <alvherre@alvh.no-ip.org>
2017-04-01 [7526e1022] BRIN auto-summarization
-->
<para>
Add full text search support for <type>JSON</> and <type>JSONB</> (Dmitry Dolgov)
Cause <acronym>BRIN</> index summarization to happen more aggressively (&Aacute;lvaro
Herrera)
</para>
<para>
This is accessed via <function>ts_headline()</> and to_tsvector. RIGHT SECTION?
Specifically, summarize the previous page range when a new page range is
created.
</para>
</listitem>
<listitem>
<!--
Author: Tom Lane <tgl@sss.pgh.pa.us>
2016-08-23 [77e290682] Create an SP-GiST opclass for inet/cidr.
Author: Alvaro Herrera <alvherre@alvh.no-ip.org>
2017-04-01 [c655899ba] BRIN de-summarization
-->
<para>
Add <acronym>SP-GiST</> index support for <type>INET</> and <type>CIDR</> data types (Emre Hasegeli)
Add function <function>brin_desummarize_range()</> to remove <acronym>BRIN</> summarization of a
specified range (&Aacute;lvaro Herrera)
</para>
<para>
These data types already had GiST support.
This allows future <acronym>BRIN</> index summarization to be more compact. CLARIFY
</para>
</listitem>
</itemizedlist>
<sect5>
<title><link linkend="indexes-types">Hash Indexes</link></title>
<itemizedlist>
<listitem>
<!--
Author: Teodor Sigaev <teodor@sigaev.ru>
2017-03-23 [218f51584] Reduce page locking in <acronym>GIN</> vacuum
Author: Robert Haas <rhaas@postgresql.org>
2017-03-14 [c11453ce0] hash: Add write-ahead logging support.
-->
<para>
Reduce page locking during vacuuming of <acronym>GIN</> indexes (Andrey Borodin)
Add write-ahead logging support to hash indexes (Amit Kapila)
</para>
<para>
This makes hash indexes crash-safe and replicated, and removes the
warning message about their use.
</para>
</listitem>
<listitem>
<!--
Author: Alvaro Herrera <alvherre@alvh.no-ip.org>
2017-04-01 [7526e1022] BRIN auto-summarization
Author: Robert Haas <rhaas@postgresql.org>
2016-11-30 [6d46f4783] Improve hash index bucket split behavior.
Author: Robert Haas <rhaas@postgresql.org>
2017-02-07 [293e24e50] Cache hash index's metapage in rel->rd_amcache.
Author: Robert Haas <rhaas@postgresql.org>
-->
<para>
Cause <acronym>BRIN</> index summarization to happen more aggressively (&Aacute;lvaro
Herrera)
Improve hash bucket split performance by reducing locking requirements
(Amit Kapila, Mithun Cy)
</para>
<para>
Specifically, summarize the previous page range when a new page range is
created.
Also cache hash index meta-information for faster lookups.
</para>
</listitem>
<listitem>
<!--
Author: Alvaro Herrera <alvherre@alvh.no-ip.org>
2017-04-01 [c655899ba] BRIN de-summarization
Author: Robert Haas <rhaas@postgresql.org>
2017-02-27 [b0f18cb77] hash: Refactor bucket squeeze code.
Author: Robert Haas <rhaas@postgresql.org>
2017-02-27 [30df93f69] hash: Refactor overflow page allocation.
Author: Robert Haas <rhaas@postgresql.org>
2017-04-03 [ea69a0dea] Expand hash indexes more gradually.
-->
<para>
Add function <function>brin_desummarize_range()</> to remove <acronym>BRIN</> summarization of a
specified range (&Aacute;lvaro Herrera)
Improve efficiency of hash index growth (Amit Kapila, Mithun Cy)
</para>
</listitem>
<listitem>
<!--
Author: Robert Haas <rhaas@postgresql.org>
2017-03-15 [6977b8b7f] Port single-page btree vacuum logic to hash indexes.
-->
<para>
This allows future <acronym>BRIN</> index summarization to be more compact. CLARIFY
Allow single-page hash pruning (Ashutosh Sharma)
</para>
</listitem>
</itemizedlist>
</sect4>
</itemizedlist>
<sect4>
<title>Locking</title>
</sect5>
<itemizedlist>
</sect4>
<sect4>
<title>Locking</title>
<itemizedlist>
<listitem>
<!--
......
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