Performance

Monitoring

Checking table sizes details and pretty printing it.

SELECT
   relname AS table_name,
   pg_size_pretty(pg_total_relation_size(relid)) AS total,
   pg_size_pretty(pg_relation_size(relid)) AS internal,
   pg_size_pretty(pg_table_size(relid) - pg_relation_size(relid)) AS external,
   pg_size_pretty(pg_indexes_size(relid)) AS indexes
FROM pg_catalog.pg_statio_user_tables
ORDER BY pg_total_relation_size(relid) DESC;

Best practices

If you are looking for a COUNT, rather than running the query to spot the count of rows at the bottom of the screen, use a subquery that counts the rows for you.

select count(*) from

(
    select
    userid
    from userschema.usertable
    where market = 'UK'
    and payingcustomer = 1
) as derivedtable;