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Diffstat (limited to 'doc/src/sgml/pgstattuple.sgml')
| -rw-r--r-- | doc/src/sgml/pgstattuple.sgml | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/doc/src/sgml/pgstattuple.sgml b/doc/src/sgml/pgstattuple.sgml index 4071da4ed94..c747a5818ab 100644 --- a/doc/src/sgml/pgstattuple.sgml +++ b/doc/src/sgml/pgstattuple.sgml @@ -270,6 +270,15 @@ leaf_fragmentation | 0 page than is accounted for by <literal>internal_pages + leaf_pages + empty_pages + deleted_pages</literal>, because it also includes the index's metapage. + <literal>avg_leaf_density</literal> is the fraction of the index size that + is taken up by user data. Since indexes have a default fillfactor of 90, + this should be around 90 for newly built indexes of non-negligible size, + but usually deteriorates over time. + <literal>leaf_fragmentation</literal> represents a measure of disorder. + A higher <literal>leaf_fragmentation</literal> indicates that the + physical order of the index leaf pages increasingly deviates from their + logical order. This can have a significant impact if a large part + of the index is read from disk. </para> <para> |