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PG_STAT_ALL_INDEXES

PG_STAT_ALL_INDEXES will contain one row for each index in the current database, showing statistics about accesses to that specific index.

Indexes can be used via either simple index scans or "bitmap" index scans. In a bitmap scan the output of several indexes can be combined via AND or OR rules, so it is difficult to associate individual heap row fetches with specific indexes when a bitmap scan is used. Therefore, a bitmap scan increments the pg_stat_all_indexes.idx_tup_read count(s) for the index(es) it uses, and it increments the pg_stat_all_tables.idx_tup_fetch count for the table, but it does not affect pg_stat_all_indexes.idx_tup_fetch.

Table 1 PG_STAT_ALL_INDEXES columns

Name

Type

Description

relid

oid

OID of the table for this index

indexrelid

oid

OID of this index

schemaname

name

Name of the schema this index is in

relname

name

Name of the table for this index

indexrelname

name

Name of this index

idx_scan

bigint

Number of index scans initiated on this index

idx_tup_read

bigint

Number of index entries returned by scans on this index

idx_tup_fetch

bigint

Number of live table rows fetched by simple index scans using this index