How can I remove specific records from TableA by joining it with TableB based on a condition? Is a DELETE with JOIN better than using a subquery?
DELETE ta
FROM TableA AS ta
JOIN TableB AS tb ON tb.KeyID = ta.ForeignKey AND [condition]
DELETE FROM TableA
WHERE ForeignKey IN (SELECT KeyID FROM TableB WHERE [condition])
i’d go with the join delete if your indexes are solid. subqry can be handy but sometimes it’s less efficient on large tables. just make sure you’re matching only the rows you need!
hey guys, i’m curious - when using join deletes, did u ever run into unexpected side effects due to a loose join condition? i think it works well with solid indexes, but any odd cases or tips from real-life experiences?
hey there! i’ve seen join dels being used quite effective when indexes are tight but subqry sometimes wins for clarity. how u handle performance issues when tables grow? any experiance with weird edge cases?
In my experience, using a DELETE with a JOIN can be more efficient when the relevant indexes are in place and the join conditions accurately limit the scope of deletion. This approach allows the query optimizer to potentially generate a more direct execution path, especially on large tables. However, caution is needed to ensure that the join condition is precise, as an improperly constrained join might lead to unintended data loss. Although subqueries offer readability, join deletions have proven beneficial in performance-critical applications in my work.
hey, join deletions are usually faster if indexes are solid, but be careful with join conds so u dont loose extra rows. sometimes subqry is easier to follow if performance isnt a must. always test and verfy conditions!