Re: [HACKERS] Aggregate "rollup"

[mlw]

Merlin Moncure wrote:

-----Original Message-----
From: mlw [mailto:[EMAIL PROTECTED]
Sent: Wednesday, March 05, 2003 3:47 PM
To: [EMAIL PROTECTED]
Subject: [HACKERS] Aggregate "rollup"
I had written a piece of code about two years ago that used the
aggregate feature of PostgreSQL to create an array of integers from an
aggregate, as:
select int_array_aggregate( column ) from table group by column

   

Do I understand correctly that this still follows the normal rules for
grouping, so that only like values are put in the array?
Example: column has values 1,1,1,2,2 spread over 5 rows.
Your query returns two rows with row1={1,1,1} and row2 = {2,2}...is this
correct?
Actually, it is more intended to put all the entries in a "one to many" 
table in a single column, as:

create table classic_one_to_many
(
   leftside    integer,
   rightside    integer
);
create table fast_lookup as select leftside, 
int_array_aggregate(rightside) from classic_one_to_many group by leftside;



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