On 27.2.2015 20:49, Alvaro Herrera wrote: > Tomas Vondra wrote: >> On 27.2.2015 20:34, Alvaro Herrera wrote: >>> Tomas Vondra wrote: >>> >>>> I think we could calls to the randomization functions into some of the >>>> regression tests (say 'create_tables.sql'), but that makes regression >>>> tests ... well, random, and I'm not convinced that's a good thing. >>>> >>>> Also, this makes regression tests harder to think, because "SELECT *" >>>> does different things depending on the attlognum order. >>> >>> No, that approach doesn't seem very useful. Rather, randomize the >>> columns in the CREATE TABLE statement, and then fix up the attlognums so >>> that the SELECT * expansion is the same as it would be with the >>> not-randomized CREATE TABLE. >> >> Yes, that's a possible approach too - possibly a better one for >> regression tests as it fixes the 'SELECT *' but it effectively uses >> fixed 'attlognum' and 'attnum' values (it's difficult to randomize >> those, as they may be referenced in other catalogs). > > Why would you care what values are used as attnum? If anything > misbehaves, surely that would be a bug in the patch. (Of course, you > can't just change the numbers too much later after the fact, because the > attnum values could have propagated into other tables via foreign keys > and such; it needs to be done during executing CREATE TABLE or > immediately thereafter.)
Because attnums are referenced in other catalogs? For example when you define PRIMARY KEY or UNIQUE constraint in the table, an index is created, which gets a row in pg_index catalog, and that references the attnum values in indkey column. If you just randomize the attnums in pg_attribute (withouth fixing all the attnum references), it's going to go BOOOOM. -- Tomas Vondra http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
