Il giorno lun, 01/12/2014 alle 09.49 -0600, Andy Colson ha scritto: > On 12/1/2014 9:23 AM, Giuseppe Sacco wrote: > > Hello, > > I have a main table and a lot of "details" tables that reference the > > main one. > > > > Every time I delete a record from the main table, a check is done on > > every details table that contain a foreign key toward main table. [...] > I can think of two options: > > 1) Don't use 50 different detail tables. A single detail table with the > type column will work much faster. Is there a good reason to break them > out? (# rows is not a good reason, btw). Basically we do have a lot of different attributes on each details tables. Let's say we use 20-30 specific columns in each of them, so why should we waste disk space and CPU cycles for handling all these columns in one table? If I understand it, you are suggesting to add about 25*50 columns in the main table and only set values for 25 columns. Moreover, our ORM would probably get crazy :-) > 2) Try inheritance. I have no idea if it'll help, but I thought I'd > read someplace where the planner knew a little more about what types of > rows go into which tables. This would probably help, but we are blocked on ANSI SQL for easily porting our application to other DBMSes. Bye, Giuseppe -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
