How to implement distributed transactions and concurrency control in MEMSQL

How to implement distributed transactions and concurrency control in MEMSQL introduction: MEMSQL is a highly scalable and distributed memory database management system that is used to process large -scale data and realize real -time query and analysis.In distributed systems, it is crucial to implement distributed transactions and concurrency control.This article will introduce how to implement these two key functions in MEMSQL and provide corresponding programming code and related configuration examples. Distributed transactions: Distributed transactions refer to transactions involving multiple database operations, which may be distributed on different nodes.MEMSQL supports distributed transactions by using MEMSQL storage and triggers. The following is an example of a distributed transaction using MEMSQL storage procedures: sql DELIMITER // CREATE PROCEDURE performDistributedTransaction() AS BEGIN START TRANSACTION; -The SQL operation of distributed transactions INSERT INTO table1 (column1) VALUES ('value1'); INSERT INTO table2 (column1) VALUES ('value2'); COMMIT; END// DELIMITER ; In the above example, we created a storage procedure called the `PerformDistributedtransaction`.Inside the storage procedure, we can perform multiple SQL operations and use the `Start Transaction` and` Commit` statements to ensure that these operations are in the same transaction.In this way, if any operation fails, the entire transaction will be rolled back. Concurrent control: Concurrent control refers to the coordination mechanism when multiple concurrent transactions access and modify the database at the same time.MEMSQL uses a multi -version concurrent control (MVCC) based on timestamp -based to achieve highly concurrent access. Here are some important configuration options that implement concurrent control in MEMSQL: 1. `isolation_level`: you can set up the isolation level of transactions.The default value is the `RepeataBle Read`.Other available isolation levels include `Read Community, and` Serializable`. 2. `max_concurrent_qureies`: you can set MEMSQL to allow the maximum query number to be performed at the same time.According to the needs of the application, you can adjust this value to limit the number of concurrent queries. The following is an example of using Memsql for concurrent access control: sql -Set the level of transaction isolation SET GLOBAL isolation_level='SERIALIZABLE'; -E concubine query -- Query1 START TRANSACTION; SELECT * FROM table1 WHERE column1='value1'; COMMIT; -- Query2 START TRANSACTION; SELECT * FROM table2 WHERE column1='value2'; COMMIT; In the above examples, we first set the global transaction isolation level to `Serializable`, which is the highest isolation level supported by MEMSQL.Then we executed two concurrent queries, and each query was in our own affairs.Because the isolation level we set is the highest, the data is locked when performing query to ensure data consistency and isolation. Summarize: This article introduces how to achieve distributed transactions and concurrency control in MEMSQL.The use of MEMSQL storage procedures and triggers can achieve distributed transactions, and can achieve concurrency control by configured transaction isolation levels and concurrency query restrictions.The above examples provide related programming code and configuration options to help readers better understand how to use Memsql to achieve these key functions in practice.