Hi all, I am writing a few pg/plsql and have no great experience, so
i'm asking here.
I need to obtain <X1>,<X2>,.. from N queryes like these:
SELECT <X1> FROM tab GROUP BY <Y1>
SELECT <X2> FROM tab GROUP BY <Y2>
SELECT <X3> FROM tab WHERE C3 GROUP BY <Y3> [eventually ORDER BY Z3];
example:
SELECT count(*),name FROM tab GROUP BY name;
SELECT sum(seconds), job FROM tab WHERE status = 1 GROUP BY job;
etc;
Doing this way the table tab would be scanned once per SELECT (tab is
a quite large table).
Since it hurts to me the idea of repeating many queryes on the
identical set of tuples
I would like to write a stored procedure who produceses these results
putting them
into a few "temporary" tables, so i ask you:
is there a way to obtain <X1>, <X2>, <X3> with a single tables scan?
May you point me to an example?
I hope i was clear enough explaining the problem.
Thank you
Stefano
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