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| author | Amit Kapila | 2019-02-20 12:07:39 +0000 |
|---|---|---|
| committer | Amit Kapila | 2019-02-20 12:07:39 +0000 |
| commit | 29d108cdecbe918452e70041d802cc515b2d56b8 (patch) | |
| tree | ea7e939c2c2c7fe4d72fb6e2d247b861a44fd87f /doc/src/sgml/pgfreespacemap.sgml | |
| parent | 41531e42d34f4aca117d343b5e40f3f757dec5fe (diff) | |
Doc: Update the documentation for FSM behavior for small tables.
In commit b0eaa4c51b, we have avoided the creation of FSM for small tables.
So the functions that use FSM to compute the free space can return zero for
such tables. This was previously also possible for the cases where the
vacuum has not been triggered to update FSM.
This commit updates the comments in code and documentation to reflect this
behavior.
Author: John Naylor
Reviewed-by: Amit Kapila
Discussion: https://postgr.es/m/CACPNZCtba-3m1q3A8gxA_vxg=T7gQf7gMbpR4Ciy5LntY-j+0Q@mail.gmail.com
Diffstat (limited to 'doc/src/sgml/pgfreespacemap.sgml')
| -rw-r--r-- | doc/src/sgml/pgfreespacemap.sgml | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/doc/src/sgml/pgfreespacemap.sgml b/doc/src/sgml/pgfreespacemap.sgml index 0122d278e39..0bcf79b02b4 100644 --- a/doc/src/sgml/pgfreespacemap.sgml +++ b/doc/src/sgml/pgfreespacemap.sgml @@ -61,6 +61,8 @@ The values stored in the free space map are not exact. They're rounded to precision of 1/256th of <symbol>BLCKSZ</symbol> (32 bytes with default <symbol>BLCKSZ</symbol>), and they're not kept fully up-to-date as tuples are inserted and updated. + In addition, small tables don't have a free space map, so these functions + will return zero even if free space is available. </para> <para> |