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MySQL  Delete with IN Clause taking more time
In MySQL 5.6 I have around 6 crores of rows. I wanted to remove rows based on Id. Here Id is the primary key.
One strange behavior I had today.
delete from tbl where id=1;
Its executed in milliseconds.
Then I did this.
CREATE TEMPORARY TABLE DELETE_ID (ID int);
Insert into DELETE_ID select id from (subery1(subquery2(subquery3)));
The DELETE_ID has around 150 ID.
Delete from tbl where id in (select id from DELETE_ID);
Its taking more than 30mins, but deleting a single row.
There were no locks or deadlock.
In innodb_trx the status was sometimes fetching rows sometimes unlocking rows.
Can anyone help me to understand why this is happening?
WHERE .. IN is slow in most cases.
Use multitable delete:
DELETE tbl.*
FROM tbl, DELETE_ID
WHERE tbl.id = DELETE_ID.id
Delete from tbl where EXISTS (SELECT id FROM DELETE_ID WHERE tbl.id = DELETE_ID.id);

WHERE .. IN is slow in most cases.
Use multitable delete:
DELETE tbl.*
FROM tbl, DELETE_ID
WHERE tbl.id = DELETE_ID.id
20181019 06:00:00 
Delete from tbl where EXISTS (SELECT id FROM DELETE_ID WHERE tbl.id = DELETE_ID.id);
20181019 06:14:18