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| author | Tomas Vondra <tomas.vondra@postgresql.org> | 2021-05-07 14:02:22 +0200 |
|---|---|---|
| committer | Tomas Vondra <tomas.vondra@postgresql.org> | 2021-05-07 14:40:41 +0200 |
| commit | 44f90ad092f95fe19bebb51465193bc63849c15f (patch) | |
| tree | 1534594e21b11f5caa64243fc5add5950208dc67 | |
| parent | 93f9af138795a7d12366187de95f4961fb07ed98 (diff) | |
| download | postgresql-44f90ad092f95fe19bebb51465193bc63849c15f.tar.gz postgresql-44f90ad092f95fe19bebb51465193bc63849c15f.zip | |
Mention statistics objects in maintenance.sgml
The docs mentioned expression indexes as a way to improve selectivity
estimates for functions, but we have a second option to improve that by
creating extended statistics. So mention that too.
Reported-by: Justin Pryzby
Discussion: https://postgr.es/m/20210505210947.GA27406%40telsasoft.com
| -rw-r--r-- | doc/src/sgml/maintenance.sgml | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/doc/src/sgml/maintenance.sgml b/doc/src/sgml/maintenance.sgml index ee6113926ac..de7fd75e1c6 100644 --- a/doc/src/sgml/maintenance.sgml +++ b/doc/src/sgml/maintenance.sgml @@ -330,7 +330,8 @@ <para> Also, by default there is limited information available about - the selectivity of functions. However, if you create an expression + the selectivity of functions. However, if you create a statistics + object or an expression index that uses a function call, useful statistics will be gathered about the function, which can greatly improve query plans that use the expression index. |