On 04/22/2014 04:58 PM, AI Rumman wrote:
Hi, Is it good to have toast table for information schema table? I am using Postgresql 8.4 and current state is: *select datname, datfrozenxid from pg_database; * datname | datfrozenxid -----------+-------------- template1 | 1462730397 template0 | 1462741467 postgres | 1562754912 jangles | 1459615432 (4 rows) * * * * *select * from pg_class where relfrozenxid = 1459615432;* relname | reltoastidxid | relhasindex | relfrozenxid ----------------+---------------+-------------+-------------- pg_toast_11447 | 11451 | t | 1459615432 (1 row) * * * * *select 11447::regclass; * regclass --------------------------------- information_schema.sql_features (1 row) Please advice.
A TOAST table is used whenever the actual table has variable length fields that meet certain criteria:
http://www.postgresql.org/docs/9.3/static/storage-toast.html information_schema.sql_features schema is: test=# \d information_schema.sql_features Table "information_schema.sql_features" Column | Type | Modifiers ------------------+-----------------------------------+----------- feature_id | information_schema.character_data | feature_name | information_schema.character_data | sub_feature_id | information_schema.character_data | sub_feature_name | information_schema.character_data | is_supported | information_schema.yes_or_no | is_verified_by | information_schema.character_data | comments | information_schema.character_data | From here you see character_data is not fixed length: http://www.postgresql.org/docs/9.3/static/infoschema-datatypes.html so a TOAST table is not out of order. I see it on my database also.
Thanks.
-- Adrian Klaver adrian.klaver@xxxxxxxxxxx -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general