Where can I find statistics for specific table column scans?
I have a very large table (near 10^9 rows) which has a few indexes however not on all fields. The non-indexed fields are mostly foreign keys to dimension tables. pg_stat_user_tables and pg_stat_user_indexes provide information on the table itself and indexed columns respectively but I cannot identify a source for specific stats for scans on singular non-index columns.
it is my understanding that a query select * from table where indexedcol=123 and nonindexedcol=456; will use the relevant index for indexedcol but do a scan on nonindexedcol.