Reposting Algorithms for Request Order Concurrency Control

The goal of concurrency control is to guarantee the correct interleaving of the operations. ROLL (Request Order Linked List) is a concurrency control method which can avoid transaction abort and minimize transaction restart. In its basic form, it requires predeclaration before a transaction is scheduled, similar to other conservative concurrency control methods, including conservative 2PL (2-Phase Locking), conservative TO (Timestamp Ordering), and conservative SGT (Serialization Graph Testing). For dynamic transactions, these sets may not be known until some operations are processed. To apply conservative concurrency control method to dynamic transactions, overdeclaration is used, although it lowers the concurrency. The goal of this paper is to develop alternative algorithms to process dynamic transactions in the ROLL setting.