Thread: pg_class.relfilenode for large tables
Hi all, when a table becomes large a new file on disk is created. Such file has the name compound by the pg_class.relfilenode attribute and an incremental index. However it seems to me this does not appears in the pg_class table. Is there any place where this extra file appears? As an example: postgres@fluca:~$ ls -l /opt/database/24601/41098* -h -rw------- 1 postgres postgres 1,0G 2007-08-20 08:48 /opt/database/24601/41098 -rw------- 1 postgres postgres 202M 2007-08-20 08:49 /opt/database/24601/41098.1 select oid, * from pg_class where relname='large'; oid | relname | relnamespace | reltype | relowner | relam | relfilenode | reltablespace | relpages | reltuples | reltoastrelid | reltoastidxid | relhasindex | relisshared | relkind | relnatts | relchecks | reltriggers | relukeys | relfkeys | relrefs | relhasoids | relhaspkey | relhasrules | relhassubclass | relfrozenxid | relacl | reloptions -------+---------+--------------+---------+----------+-------+-------------+---------------+----------+-------------+---------------+---------------+-------------+-------------+---------+----------+-----------+-------------+----------+----------+---------+------------+------------+-------------+----------------+--------------+--------+------------ 41098 | large | 2200 | 41099 | 16386 | 0 | 41098 | 0 | 156813 | 1.12921e+07 | 0 | 0 | f | f | r | 9 | 0 | 0 | 0 | 0 | 0 | f | f | f | f | 11412913 | | (1 riga) Thanks, Luca
On Mon, Aug 20, 2007 at 08:57:14AM +0200, Luca Ferrari wrote: > Hi all, > when a table becomes large a new file on disk is created. Such file has the > name compound by the pg_class.relfilenode attribute and an incremental index. > However it seems to me this does not appears in the pg_class table. Is there > any place where this extra file appears? No, it is a mechanism to deal with filesize limits of various OSes. Files are cut so that each file is no more than one gigabyte. If the table shrinks it will go away again. There's no reason to list it in the database as it isn't an independant object. Have a nice day, -- Martijn van Oosterhout <kleptog@svana.org> http://svana.org/kleptog/ > From each according to his ability. To each according to his ability to litigate.