diff options
| -rw-r--r-- | doc/src/sgml/release-12.sgml | 77 |
1 files changed, 50 insertions, 27 deletions
diff --git a/doc/src/sgml/release-12.sgml b/doc/src/sgml/release-12.sgml index 4a6c989f3f0..fcc49ffcf9a 100644 --- a/doc/src/sgml/release-12.sgml +++ b/doc/src/sgml/release-12.sgml @@ -606,22 +606,64 @@ Author: Tom Lane <tgl@sss.pgh.pa.us> <listitem> <!-- -Author: Alexander Korotkov <akorotkov@postgresql.org> -2018-07-28 [d2086b08b] Reduce path length for locking leaf B-tree pages during +Author: Peter Geoghegan <pg@bowt.ie> +2019-03-20 [dd299df81] Make heap TID a tiebreaker nbtree index column. +Author: Peter Geoghegan <pg@bowt.ie> +2019-03-20 [fab250243] Consider secondary factors during nbtree splits. Author: Peter Geoghegan <pg@bowt.ie> 2019-03-25 [f21668f32] Add "split after new tuple" nbtree optimization. --> <para> - Improve speed of btree index insertions (Peter Geoghegan, - Alexander Korotkov) + Improve performance and space utilization of btree indexes with + many duplicates (Peter Geoghegan, Heikki Linnakangas) + </para> + + <para> + Previously, duplicate index entries were stored unordered within + their duplicate groups. This caused overhead during index + inserts, wasted space due to excessive page splits, and reduced + <command>VACUUM</command>'s ability to recycle entire pages. + Duplicate index entries are now sorted in heap-storage order. + </para> + + <para> + Indexes <application>pg_upgraded</application> from previous + releases will not have these benefits. + </para> + </listitem> + + <listitem> +<!-- +see commits above +--> + + <para> + Allow multi-column btree indexes to be smaller (Peter Geoghegan, + Heikki Linnakangas) + </para> + + <para> + Internal pages and min/max leaf page indicators now only store + index keys until the change key, rather than all indexed keys. + This also improves the locality of index access. </para> <para> - The new code improves the space-efficiency of page splits, - reduces locking overhead, and gives better performance for - <command>UPDATE</command>s and <command>DELETE</command>s on - indexes with many duplicates. + Indexes <application>pg_upgraded</application> from previous + releases will not have these benefits. + </para> + </listitem> + + <listitem> +<!-- +Author: Alexander Korotkov <akorotkov@postgresql.org> +2018-07-28 [d2086b08b] Reduce path length for locking leaf B-tree pages during +--> + + <para> + Improve speed of btree index insertions by reducing locking + overhead (Alexander Korotkov) </para> </listitem> @@ -680,25 +722,6 @@ Author: Tom Lane <tgl@sss.pgh.pa.us> <listitem> <!-- -Author: Peter Geoghegan <pg@bowt.ie> -2019-03-20 [dd299df81] Make heap TID a tiebreaker nbtree index column. -Author: Peter Geoghegan <pg@bowt.ie> -2019-03-20 [fab250243] Consider secondary factors during nbtree splits. ---> - - <para> - Have new btree indexes sort duplicate index entries in heap-storage - order (Peter Geoghegan, Heikki Linnakangas) - </para> - - <para> - Indexes <application>pg_upgraded</application> from previous - releases will not have this ordering. - </para> - </listitem> - - <listitem> -<!-- Author: Heikki Linnakangas <heikki.linnakangas@iki.fi> 2019-03-05 [fe280694d] Scan GiST indexes in physical order during VACUUM. --> |