I want to do it on a very big tables(100M records). Do you think that it will be slow ? I mean if I have an AccessExclusiveLock for a lot of time I cant just run a query and take my time until it finishes..
בתאריך יום ה׳, 1 בנוב׳ 2018 ב-13:55 מאת Evan Bauer <evanbauer@mac.com>:
Mariel,
Just run a query and make certain that all values currently stored in the column fit in 4 bytes (+/- 2,147,483,648) before doing the ALTER.
I want to change the column type from bigint to int to save space. By doing so, does it include some risks ? As I see it, I should only run vacuum full afterwards if I want to return space to the os right ?