Stephen Cook wrote:
I am curious (coming from a MS SQL Server background, I just started
playing with PostgreSQL recently).
What type of situation would warrant a statement-level trigger that
can't access the old and new values? Without that access, isn't the
only information you get is the fact that an operation occurred on the
table? Or am I missing something?
-- Stephen
What about this. Suppose you have this table "planets":
planet_name | star_id|....
There is a lot of stars, right? And if a very common query involves a
"select planet_name, count(*) from planets group by star_id"....Well, if
there is 1.000.000.000 of galaxies, and 1.000.000.000.000 of stars per
galaxy...Thats a lot of planets to count!!! So maybe you want a helper
table who maintains such of subtotals.
Well, each time you discover a new galaxy, insert every planet in the
monster table, and *after* all the inserts, run a trigger for updating
the helper table.
Cheers.
Gerardo
---------------------------(end of broadcast)---------------------------
TIP 5: don't forget to increase your free space map settings
