AliSQL: [Feature] issue #33 HINT SOLUTION FOR INVENTORY

Description

-----------

Usually Inventory Center has some hot commodity, corresponding to

MySQL table records. So update the record will cause serious contention simultaneously.

This patch supply a queue for every hot commondity to serialize update

according to statement hint.

Hints:

QUEUE_ON_PK

COMMIT_ON_SUCCESS

ROLLBACK_ON_FAIL

TARGET_AFFECT_ROW

Usage

-----

update COMMIT_ON_SUCCESS ROLLBACK_ON_FAIL QUEUE_ON_PK 1 TARGET_AFFECT_ROW 1 t1 set c=c-1 where id=1;