31 results about "Multiversion concurrency control" patented technology

A transaction creates a wait for dependency on a version in a main memory database implementing a multi-version concurrency control scheme. The wait for dependency allows the transaction to update the version while other transactions are reading the version. The multi-version concurrency control scheme also allows commit dependencies to be implementing concurrently with wait for dependencies. Commit dependencies allow a transaction to read an updated version before the updated version is committed.

The invention discloses a distributed transaction processing system using a multi-type replica in a decentralized schema. The distributed transaction processing system comprises a transaction interface module, a transaction processing module and a transaction memory module, wherein the transaction interface module comprises an outward interface sub-module and a transaction preprocessing sub-module, the transaction processing module comprises a multi-type replica sub-module, a read transaction processing module, a replica group transaction state sub-module, a read request distribution sub-module, a replica repair sub-module, a multiversion concurrency control (MVCC) read sub-module, a local writing transaction processing sub-module, a local writing transaction paxos replica consistency sub-module, a local writing transaction commit sub-module, a global writing transaction processing sub-module, a main sub-transaction paxos replica consistency sub-module, a secondary sub-transaction paxos replica consistency sub-module and a global writing transaction commit sub-module. The distributed transaction processing system can solve the problems in an existing system that the reading and writing environment is limited, reading and writing availability can not be configured autonomously according to requirements of application, a global transaction depends on locking and cost is high.

The related compression storage method for great much data comprises: detecting CPU type to select matched storage strategy; saving one piece of record with integral information in website as the reference for other records; noting the reference record difference by increment means; removing the last-version data in history to realize the dynamic conversion for history and active data; according to frequency of data value, recoding data to calculate without decoding. This invention can improve query efficiency with less storage space.

The invention discloses a trusted log recording method based on blockchain, provides an overall framework suitable for a distributed log system based on blockchain, and provides each module and each log in the overall architecture. Layered specific design; especially in the consensus layer of the distributed accounting module, the traditional practical Byzantine fault-tolerant algorithm is improved by combining multi-version concurrency control methods, random algorithms and event monitoring mechanisms. The invention is used to solve the lack of trusted log function for further consensus verification of the correctness of the log generated by the node and the operation authority of the node in the existing distributed system, and to improve the problem of large communication volume of the traditional practical Byzantine fault tolerance algorithm.