Can the following query be optimized ?
DELETE FROM COLOR_TAGS
WHERE COLOR_PROJECTID = $id
AND NoteID IN(
SELECT ID FROM note_note
WHERE BibID=$bid AND isdel=0);
Can the following query be optimized ?
DELETE FROM COLOR_TAGS
WHERE COLOR_PROJECTID = $id
AND NoteID IN(
SELECT ID FROM note_note
WHERE BibID=$bid AND isdel=0);
Add composite indexes to your tables:
On COLOR_TAGS
, index (COLOR_PROJECTID, NoteID)
On note_note
, index (isdel, BibID, ID)
.