Emi Lu wrote:
Tried to run:
delete from tableA where id <600000;
It is extremely slow.
id is integer and also the primary key. tableA has around 90000
records.
(I do not want to run truncate since I have some foreign key constraint
setup based on tableA. Besides not all data I want to delete; only part
of them).
Since you have some FK constrains on A, so delete each line of A will
confirm that it is not depended, which involves a lookup on the
dependent
table. Do you have indexes built on these dependents?
No, I do not have indexes setup for those dependents.
If I setup index for those columns, it will speed up the deletion, right?
Thank you.
http://archives.postgresql.org/pgsql-general/2003-02/msg01615.php
If deletioin is 80% data, will index helps?
Emi
