From: elizabeth-christensen 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. - 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 BRIN) + and does not update any columns referenced by the table's non-summary + indexes, including expression and partial non-summary indexes. @@ -1114,7 +1113,7 @@ data. Empty in ordinary tables. - 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. @@ -1130,11 +1129,10 @@ data. Empty in ordinary tables. - 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 - HOT updates by decreasing a table's fillfactor. + 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 HOT updates by decreasing + a table's fillfactor. If you don't, HOT 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