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| author | Tom Lane <tgl@sss.pgh.pa.us> | 2011-10-08 11:09:18 -0400 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2011-10-08 11:09:18 -0400 |
| commit | c78d8cd1464bc6b69fdc72f9ce51407c89554ece (patch) | |
| tree | ebb45adb3c5b6d6d208f8db930593f2814c908c1 | |
| parent | b324384f6bd5d661efeddb83d7f607781e96947d (diff) | |
| download | postgresql-c78d8cd1464bc6b69fdc72f9ce51407c89554ece.tar.gz postgresql-c78d8cd1464bc6b69fdc72f9ce51407c89554ece.zip | |
Note that index-only scans can affect idx_tup_fetch.
An index-only scan that avoids heap fetches will increment idx_tup_read
but not idx_tup_fetch.
| -rw-r--r-- | doc/src/sgml/monitoring.sgml | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml index a19e3f06ccc..b9dc1d20013 100644 --- a/doc/src/sgml/monitoring.sgml +++ b/doc/src/sgml/monitoring.sgml @@ -507,7 +507,8 @@ postgres: <replaceable>user</> <replaceable>database</> <replaceable>host</> <re considering bitmap scans, because <structfield>idx_tup_read</> counts index entries retrieved from the index while <structfield>idx_tup_fetch</> counts live rows fetched from the table; the latter will be less if any - dead or not-yet-committed rows are fetched using the index. + dead or not-yet-committed rows are fetched using the index, or if any + heap fetches are avoided by means of an index-only scan. </para> </note> |