Hi all,
I am going through PostgreSQL documentation on how row estimation is done in PostgreSQL.
http://www.postgresql.org/docs/current/static/row-estimation-examples.html
There is a reference to cardinality (rel_cardinality) there. But that is an estimate of the number of rows in the table, right?
How many unique values are there in a column (cardinality), that is estimated while finding out selectivity?
Regards,I am going through PostgreSQL documentation on how row estimation is done in PostgreSQL.
http://www.postgresql.org/docs/current/static/row-estimation-examples.html
There is a reference to cardinality (rel_cardinality) there. But that is an estimate of the number of rows in the table, right?
How many unique values are there in a column (cardinality), that is estimated while finding out selectivity?
