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prefacestay Mybatis source code - execution process of Executor In this article, the first level cache and second level cache in Mybatis will be described in combination with examples and source code.textI Display of L1 cache mechanismIn Mybatis, if the same SQL statement is executed multiple times, Mybatis provides a level-1 cache mechanism to ...

A friend asked me to write it a few days ago. I recorded it casually. I felt it was not difficult. I just encountered some problems when writing. The optimization is not very convenient. There are good optimization methods, welcome to share! (database at the end of the article) requirement 1) Query the proportion of sales amount of all product ...

3. Table related operations 1. Introduction to storage engine 1.1. What is a storage engine Database = = = folder created in mysql Table = = = file created in Library In real life, the files we use to store data have different types, and each file type corresponds to its own different processing mechanism: for example, txt type for text p ...

The author's official account is welcome to exchange. In the process of MySQL master-slave replication, errors are inevitable due to various reasons. How to solve the errors in the replication process? This article will demonstrate how to skip the corresponding errors in the slave database when the master-slave inconsistency is caused by the ...

1, Background   when we use the database, we will inevitably encounter the situation that the data is deleted by mistake, which may be business operation errors and code bug s; It may also be an operation and maintenance error, etc; However, we can divide all operations into the following categories: Data loss due to DMLData loss due ...

See the architecture and introduction of tidb TiDB Overall Architecture | PingCAP Docs understands the overall architecture of TiDB.https://docs.pingcap.com/zh/tidb/v4.0/tidb-architecture brief introduction            TiDB yes PingCAP The Open Source Distributed Relational Database, designed and developed independently by the company, is a hy ...

1. Introduction to xtrabackup MySQL cold standby, mysqldump and MySQL hot copy cannot realize incremental backup of the database. In the actual production environment, incremental backup is very practical. If the data is greater than 50G or 100G and the storage space is sufficient, full backup can be carried out every day. If the amount of ...

Video link: https://www.bilibili.com/video/BV1iF411z7Pu 1.3. 1. Basic operation of index 1.3. 1.1. Index overview What is the index Index is to build a data model through some algorithm to quickly find the row with a specific value in a column. Without index, MySQL must read the whole table from the first record until the relevant row ...

Zero foundation of MySQL from introduction to mastery (constraint) MySQL constraints concept constraint Constraints are actually constraints on the data in the table effect The purpose of adding constraints is to ensure the integrity and effectiveness of the records in the table. For example, the values of the column (mobile phone number) ...

Management of constraints Common constraints A restriction used to restrict the data in a table in order to ensure the accuracy and reliability of the data in the table classification Not null: non null, used to ensure that the value of this field cannot be nullDefault: default to ensure that this field has a default valuePrimary key: p ...