Hi All,
I am using Postgresql 9.1 where have a partitioned table as below:
events_20150101
events_20150102
events_20150103
...
events_overflow
When I am running the following query it gives me result:
SQL 1:
select all relname, pg_total_relation_size(relname::text) as s, substr(relname,18)::date as dt from pg_stat_user_tables where schemaname = 'partitions' and relname not like '%overflow'
But when I run the following one, it gives me error:
SQL 2:
select * as ts
from
(
select relname, pg_total_relation_size(relname::text) as s, substr(relname,18)::date as dt from pg_stat_user_tables where schemaname = 'partitions' and relname not like '%overflow' order by pg_total_relation_size(relname::text) desc
) as q
where dt = '2015-01-01'::date;
ERROR: invalid input syntax for type date: ""
However, explain is showing plan:
Sort (cost=202.03..202.04 rows=1 width=64)
Sort Key: (pg_total_relation_size(((pg_stat_all_tables.relname)::text)::regclass))
-> Subquery Scan on pg_stat_all_tables (cost=201.93..202.02 rows=1 width=64)
-> HashAggregate (cost=201.93..201.99 rows=1 width=136)
-> Nested Loop Left Join (cost=0.00..201.92 rows=1 width=136)
-> Nested Loop (cost=0.00..194.23 rows=1 width=132)
Join Filter: (c.relnamespace = n.oid)
-> Seq Scan on pg_namespace n (cost=0.00..1.39 rows=1 width=68)
Filter: ((nspname <> ALL ('{pg_catalog,information_schema}'::name[])) AND (nspname !~ '^pg_toast'::text) AND (nspname = 'partitions'::name))
-> Seq Scan on pg_class c (cost=0.00..192.77 rows=6 width=72)
Filter: ((relkind = ANY ('{r,t}'::"char"[])) AND (relname !~~ '%overflow'::text) AND ((substr((relname)::text, 18))::date = '2015-01-01'::date))
-> Index Scan using pg_index_indrelid_index on pg_index i (cost=0.00..7.66 rows=2 width=8)
Index Cond: (c.oid = indrelid)
Again, if I create a table and run the query it runs:
SQL 3:
create table dba.tbl_list as select all relname, pg_total_relation_size(relname::text) as s, substr(relname,18)::date as dt from pg_stat_user_tables where schemaname = 'partitions' and relname not like '%overflow' ;
SELECT 558
\d+ dba.tbl_list
Table "dba.tbl_list"
Column | Type | Modifiers | Storage | Description
---------+--------+-----------+---------+-------------
relname | name | | plain |
s | bigint | | plain |
dt | date | | plain |
Has OIDs: no
SQL 4:
select * from dba.tbl_list where dt = '2015-01-01';
relname | s | dt
---------------------------+------------+------------
events_20150101 | 1309966336 | 2015-01-01
(1 row)
Why the 2nd query is showing error? Is it a bug? Or am I doing any silly?
Any advice, please.
Thanks & Regards.
