Hello > 1. ALTER TABLE clusters ADD COLUMN "is_paid" BOOLEAN DEFAULT FALSE; this is wrong. To avoid large table lock you need DEFAULT NULL: ALTER TABLE clusters ADD COLUMN "is_paid" BOOLEAN DEFAULT NULL; Default null changes only system catalog, default with any non-null value will rewrite all rows. After adding column you can set default value - it applied only for future inserts: ALTER TABLE clusters ALTER COLUMN "is_paid" SET DEFAULT FALSE; And then you can update all old rows in table by small chunks. Finally, when here is no NULL values you can set not null: ALTER TABLE clusters ALTER COLUMN "is_paid" SET NOT NULL; But unfortunately this locks table for some time - smaller what rewrite time, but time of full seqscan. I hope my patch [1] will be merged and not null can be set in future by temporary adding check constraint (not valid, then validate) - which not require large table lock [1] https://www.postgresql.org/message-id/flat/81911511895540@xxxxxxxxxxxxxxxx#81911511895540@xxxxxxxxxxxxxxxx Regards, Sergei
