Batch update million records in prd DB

[Yi Sun]

Hello,

Now need to update several million records in a table in prd DB, if can use
batch update 1000 records and commit each time, if it will affect prd
application like below sample script please?

Sample script:

DO $MAIN$
DECLARE
  affect_count integer;
  chunk_size CONSTANT integer :=1000;
  sleep_sec CONSTANT numeric :=0.1;
BEGIN

  loop

    exit when affect_count=0;

      UPDATE tbl a
      SET name = ''
      WHERE a.id IN (SELECT id
                       FROM tbl b
                       WHERE name IS NULL
                       LIMIT chunk_size);

      GET DIAGNOSTICS affect_count = ROW_COUNT;

      commit;

      PERFORM pg_sleep(sleep_sec);

  end loop;
END;
$MAIN$;

Thanks and best regards