Hi group! If I want to change the default order of two columns of a table, can I just manipulate the values in pg_catalog.pg_attribute.attnum? I am trying to do this in pg 8.1.9. Works the same in pg 8.2.x I would assume? BEGIN; UPDATE pg_catalog.pg_attribute SET attnum = 4 WHERE attrelid = 12345 AND attname = 'col3' AND attnum = 2; UPDATE pg_catalog.pg_attribute SET attnum = 2 WHERE attrelid = 12345 AND attname = 'col2' AND attnum = 3; UPDATE pg_catalog.pg_attribute SET attnum = 3 WHERE attrelid = 12345 AND attname = 'col3' AND attnum = 4; COMMIT; -- That's how I got the necessary data (attrelid, attnum): SELECT a.attrelid, a.attname, a.attnum FROM pg_class c, pg_namespace nc, pg_attribute a WHERE c.relnamespace = nc.oid AND a.attrelid = c.oid AND nc.nspname = 'myschema' AND c.relname = 'mytbl' AND a.attnum >= 1; - I assume I have to avoid holes in the numbering of the visible attributes of the relation. - To avoid temporary duplicates in attnum I first move one of the columns to a new postition, so I need 3 operations to switch the position of two fields. - All in one transaction, so it should should be immune to other people trying to access the table. Anything else I need to bear in mind? Does it work like this at all? Are there side effects? I did not find any contradicting info here: http://www.postgresql.org/docs/8.1/interactive/catalog-pg-attribute.html I have tried it on a dummy table and it _seems_ to work .. I know it is dangerous to mess with data in pg_catalog. But recreating a table is such a pain when several foreign key constraints point to it. So maybe one of more knowing could comment on it? Thanks in advance! Regards Erwin
