On 12/18/17 00:17, Amit Langote wrote: > I agree with the Robert's point which both David and Michael seem to agree > with that we shouldn't really be changing what pg_relation_size() is doing > under the covers. And I guess the same for pg_table_size(), too. Both of > those functions and their siblings work with relations that possess > on-disk structures and have associated relations (TOAST, indexes) that in > turn possess on-disk structures. It seems quite clearly documented as > such. Partitioned tables are different in that they neither possess > on-disk structures nor have any relations (TOAST, indexes) associated > directly with them. Instead, they have partitions that are the relations > that aforementioned dbsize.c functions are familiar with.
Here is another idea. If we had a function pg_partition_root(regclass) returns regclass (returning itself for non-partitioned relations), then users can easily construct queries to get the results they want in different shapes, e.g., select pg_partition_root(c.oid), c.relname, pg_table_size(c.oid) from pg_class c order by 1 select pg_partition_root(c.oid), sum(pg_table_size(c.oid)) from pg_class c group by 1 -- Peter Eisentraut http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
