I believe that tables' clustering factors are stored in pg_stats.correlation. Here is how I came to this conclusion: create table narrow_table as with numbers as( select generate_series as n from generate_series(0,1048575)) select n as seq_number, (n/1024) + ((n%1024)<<10) as rand_number from numbers; alter table narrow_table add constraint pk_narrow_table primary key(seq_number); alter table narrow_table add constraint unq_narrow_table unique(rand_number); cluster narrow_table using pk_narrow_table; vacuum full analyze narrow_table; Now my table is physically ordered by its primary key. Apparently the following query indicates that: SELECT attname, correlation FROM pg_stats WHERE tablename LIKE '%narrow%'; "seq_number";1 "rand_number";0.00665399 Please correct me if I am wrong, or confirm my conclusion. -- View this message in context: http://postgresql.nabble.com/Is-clustering-factor-stored-in-pg-stats-correlation-tp5831610.html Sent from the PostgreSQL - general mailing list archive at Nabble.com. -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
