Method for recording event logs and database engine

Abstract

The invention discloses a method for recording event logs and a database engine, and belongs to the technical field of databases. The method includes the steps that an SQL request is received; according to the SQL request, data pages corresponding to the SQL request are modified; corresponding event logs are generated for the modification; the event logs are partitioned to obtain a plurality of log segments, the log segments are written into a plurality of buffer queues, and the log segments in the buffer queues are written into a log file. The database engine comprises a receiving module, a modifying module, a generating module and writing-in module. According to the method for recording event logs and the database engine, the event logs can be recorded in parallel; due to the fact that the buffer queues are multiple and written into the log file in a parallel processing mode, not only is the lock granularity of the event log buffer queues reduced, but also the speed for writing the log file into a disk is greatly increased, the performance of a database system is improved, and user experience is improved.

Description

technical field [0001] The invention relates to the technical field of databases, in particular to a method for recording transaction logs and a database engine. Background technique [0002] The transaction log of the database is a file used to record every modification activity of the database. The transaction log is the basis for undoing transactions and recovering them in case of failure. Different from ordinary system logs, database transaction logs need to ensure sequence consistency when recording changes in the database system. When recovering from a fault, it is also required to recover completely in the order in which transactions occurred. Usually, in order to reduce input and output, the database system adopts the WAL (Write-Ahead Logging, write-ahead log) mechanism to record the transaction log. WAL means that modifications to data files must occur after these modifications have been recorded in the transaction log, that is, after the log records describing th...

AI Technical Summary

Problems solved by technology

However, the serial method makes the transaction log writing to the disk very slow, and a single cache queue will cause the resource to be locked when responding to a request, and other requests must wait for unlocking, so the lock granularity is large, resulting in reduced availability of the database system , poor user experience

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