Sat, 4 Dec 2010 13:24:27 +0000
Miguel Vaz <pagongski@gmail.com>
> Your solution seems great and does the trick, but if most (and having
> some items that relate to all 3 tables) of my relations are between
> two tables, close to 1/3 of the id_tx fields would be null, correct?
> I may be wrong in thinking like this, but always had this thing of
> keeping tables very tight regarding null entries. Am i thinking
> wrong? Or maybe worrying too much on less important things. :-)
Well, test it. EXPLAIN is a cool thing.
http://www.postgresql.org/docs/9.0/static/sql-explain.html
http://explain.depesz.com/
http://explain.depesz.com/help/
You can do some optimisation and significantly improve performance
of particular SELECT queries by creating proper indexes. I would not be
too worried about the NULLs. I do not know, how much data and how large
database we are talking about. Maybe you should consult someone more
experienced. I only work with small databases: 2 GB of data, less than
a million rows per table.
Oh, and I am CC'ing the mailing list. ;)
Cheers!
--
Michał Roszka
mike@if-then-else.pl
