Hi, If this question doesn't belong to this mailing list, please pardon.
I have a table with a few hundred million rows, and I need to write a query that does something like follows -- Change all the values of a column to null where the value cannot be casted to numeric(20,4) I have it as varchar, and I need to convert it to numeric(20,4). I am using this query - alter table optiondata ALTER volume TYPE numeric(20,4) using cast(volume as numeric(20,4)); then wait for DB to complain, and then update that value to null, and just keep doing this till all garbadge is removed :-( Thanks, Amit ---------------------------(end of broadcast)--------------------------- TIP 4: Have you searched our list archives? http://archives.postgresql.org