How to efficiently delete rows while NOT using Truncate Table in a 500,000+ rows table

Question

Let\'s say we have table Sales with 30 columns and 500,000 rows. I would like to delete 400,000 in the table (those where \"toDelete=\'1\'\").

Answer 1

Calling DELETE FROM TableName will do the entire delete in one large transaction. This is expensive.

Here is another option which will delete rows in batches :

deleteMore:
DELETE TOP(10000) Sales WHERE toDelete='1'
IF @@ROWCOUNT != 0
    goto deleteMore