Hi,

I need to populate a new column in a Postgres 8.3 table. The SQL would be
something like "update t set col_c = col_a + col_b". Unfortunately, this
table has 110 million rows, so running that query runs out of memory.
In Oracle, I'd turn auto-commit off and write a pl/sql procedure that keeps
a counter and commits every 10000 rows (pseudocode):

define cursor curs as select col_a from t
while fetch_from_cursor(curs) into a
     update t set col_c = col_a + col_b where col_a = a
     i++
     if i > 10000
         commit; i=0;
     end if;
     commit;

PL/pgsql doesn't allow that because it doesn't support nested transactions.
Is there an equivalent Postgres way of doing this?

cheers,
Len
-- 
len.wal...@gmail.com skype:lenwalter
msn:len.wal...@gmail.com<msn%3alen.wal...@gmail.com>

Reply via email to