public inbox for [email protected]  
help / color / mirror / Atom feed
From: Elizabeth Christensen <[email protected]>
To: [email protected]
Subject: [PATCH] updates to docs about HOT updates for BRIN
Date: Mon, 26 Feb 2024 14:29:37 -0600
Message-ID: <CABoUFXRjisr58Ct_3VsFEdQx+fJeQTWTdJnM7XAp=8MUbtoa9A@mail.gmail.com> (raw)

Hello,

I have a small documentation patch to the HOT updates page
<https://www.postgresql.org/docs/current/storage-hot.html>to add references
to summary (BRIN) indexes not blocking HOT updates
<https://www.postgresql.org/message-id/[email protected]...;,
committed 19d8e2308b.

Thanks,
Elizabeth Christensen


Attachments:

  [application/octet-stream] 0001-Adding-Summary-Index-Info-to-HOT-Update-Documentatio.patch (2.5K, ../CABoUFXRjisr58Ct_3VsFEdQx+fJeQTWTdJnM7XAp=8MUbtoa9A@mail.gmail.com/3-0001-Adding-Summary-Index-Info-to-HOT-Update-Documentatio.patch)
  download | inline diff:
From: elizabeth-christensen <[email protected]>
Date: Mon, 26 Feb 2024 12:09:22 -0600
Subject: [PATCH] Adding Summary Index Info to HOT Update Documentation page

Commit 19d8e2308b changed when the HOT update optimization is possible but neglected to update the Heap-Only Tuples (HOT) documentation.  This patch updates that documentation accordingly.

Author: Elizabeth Christensen
Backpatch-through: 16
Discussion: 
---
 doc/src/sgml/storage.sgml | 12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/storage.sgml b/doc/src/sgml/storage.sgml
index 3ea4e5526d..f12ed31483 100644
--- a/doc/src/sgml/storage.sgml
+++ b/doc/src/sgml/storage.sgml
@@ -1097,8 +1097,7 @@ data. Empty in ordinary tables.</entry>
   <itemizedlist>
    <listitem>
     <para>
-     The update does not modify any columns referenced by the table's
-     indexes, including expression and partial indexes.
+     The update only modifies columns which are un-indexed or are only 
+     indexed with summarizing indexes (such as <acronym>BRIN</acronym>) 
+     and does not update any columns referenced by the table's non-summary 
+     indexes, including expression and partial non-summary indexes.
      </para>
    </listitem>
    <listitem>
@@ -1114,7 +1113,7 @@ data. Empty in ordinary tables.</entry>
   <itemizedlist>
    <listitem>
     <para>
-     New index entries are not needed to represent updated rows.
+     New index entries are not needed to represent updated rows, 
+     however, summary indexes may still need to be updated.
     </para>
    </listitem>
    <listitem>
@@ -1130,11 +1129,10 @@ data. Empty in ordinary tables.</entry>
  </para>
 
  <para>
-  In summary, heap-only tuple updates can only be created
-  if columns used by indexes are not updated.  You can
-  increase the likelihood of sufficient page space for
-  <acronym>HOT</acronym> updates by decreasing a table's <link
-  linkend="reloption-fillfactor"><literal>fillfactor</literal></link>.
+  In summary, heap-only tuple updates can only be created if columns used by 
+  non-summary indexes are not updated. You can increase the likelihood of 
+  sufficient page space for <acronym>HOT</acronym> updates by decreasing 
+  a table's <link linkend="reloption-fillfactor"><literal>fillfactor</literal></link>.
   If you don't, <acronym>HOT</acronym> updates will still happen because
   new rows will naturally migrate to new pages and existing pages with
   sufficient free space for new row versions.  The system view <link
-- 
2.37.0

view thread (5+ messages)  latest in thread

reply

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Reply to all the recipients using the --to and --cc options:
  reply via email

  To: [email protected]
  Cc: [email protected], [email protected]
  Subject: Re: [PATCH] updates to docs about HOT updates for BRIN
  In-Reply-To: <CABoUFXRjisr58Ct_3VsFEdQx+fJeQTWTdJnM7XAp=8MUbtoa9A@mail.gmail.com>

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

This inbox is served by agora; see mirroring instructions
for how to clone and mirror all data and code used for this inbox