Avoid downtream repeating parse SQL

[lance6716]

Feature Request

Is your feature request related to a problem? Please describe:

seems DM will generate a lot of similar SQL, for example, for same table all INSERT should be the same. So using one PREPARE and many EXECUTE will reduce downstream SQL parsing time.

Another way is that try to attach many rows in one statement, for example, INSERT ... VALUES ((), (), ()) or DELETE ... WHERE .. OR .. OR ..

Describe the feature you'd like:

see above

Describe alternatives you've considered:

Teachability, Documentation, Adoption, Migration Strategy:

[hidehalo]

It seems we need a prepared statement cache?

[lance6716]

It seems we need a prepared statement cache?

TiDB will handle the cache if we send PREPARE SQL

[hidehalo]

It seems we need a prepared statement cache?

TiDB will handle the cache if we send PREPARE SQL

Ok, I get it:

a) use prepare replace to plaintext query. b) merge batch insert/delete of operations into bulk operation.

[lance6716]

TiDB has spent 9% CPU on parse. And SQL digest generating (3%) will be quicker