Bart Grantham wrote:
Hello again. I had a problem a few weeks ago with using IN ( some_array
) having really rough performance. Special thanks to Ron Mayer for the
suggestion of using int_array_enum(some_array) to join against. I had
to upgrade to PG8 but that technique works really well. Now I have a
question about array manipulation. Specifically, how can I build an
array from the result of a query without resorting to array_append()?
Well, the same contrib module with int_array_enum() also has
aggregate called int_array_aggregate that turns a column into an array.
-- my_array is an INT[]
_my_array := select some_column from some_table;
so this:
SELECT int_array_aggregate(some_column) from some_table;
might be what you want.
... in plpgsql?
Well... the function from the contrib module was in C, so I guess
it doesn't strictly meet what you asked, but it works very well
for me. ;-)
Ron Mayer
PS: the stuff in /contrib/intarray may be useful too, for
indexing, merging, and many other tricks on the integer arrays.
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