Concurrency Control Using Dynamic Versioning on Cache Conscious T-trees in Main Memory Database Systems

초록

We present a concurrency control scheme on cache conscious index structures in main memory database systems. We study this issue based on T-tree and propose a cache conscious T-tree(CCT-tree) by changing some storage characteristics. In addition, for applications involving more read-only transactions than update transactions, we propose a dynamic versioning scheme to reduce the locking and latching cost. This scheme enables read-only transactions read correct version without holding any locks or latches, while update transactions only obtain a few locks or latches without deadlocks. Version management is designed to support high concurrency level and low space overhead. The interaction between dynamic versioning and CCT-tree is considered so that all versions can be accessed through indexing. Experiment results show that this scheme can improve the performance in coucurrent environment significantly.