Re: ALTER TABLE and vacuum

On 06/06/16 10:55, Rick Widmer wrote:
> Do I need to vacuum after an alter table command?

If the specific command you do rewrites the table, you absolutely should
vacuum in order to restore the visibility map.  Otherwise, it not necessary.

> Does it matter if there is a default or if we accept NULLs for the new
> field?

Yes, that makes a difference.  If you add a column that defaults to
NULL, the table will not be rewritten.
--
Vik Fearing                                          +33 6 46 75 15 36
http://2ndQuadrant.fr     PostgreSQL : Expertise, Formation et Support