mysql table

MySQL table partitioning and sub-library tables are all designed to increase the throughput of the database. Partitions are similar to sub-tables, which logically divide a large amount of data into multiple tables, either horizontally or vertically.

When I changed their code today, I encountered a problem with MySQL table name and database keyword.Because the table name is a keyword, resulting in additions and deletions are error-checking.Hibernate:select leave0_.id as Id22_, Leave0_.stunumber

This article mainly describes the operation of MySQL in the command interface of Navicat. Mainly involves the establishment of table structure, and the data in the table to increase the deletion of modified query and other actions. A simple MySQL

Refer to http://www.jb51.net/article/50047.htm "MySQL row level lock, table level lock, page level lock Details"Page level: Engine BDB.Table level: Engine MyISAM, understood to lock the entire table, can read at the same time, write NoRow level:

Because the project needs to be based on the MySQL table data generation INSERT INTO statement, found some out-of-the-box code, the original author who did not know, but found that there is a bug, can not be applied, hence the code of others have

One: OverviewCompared with other databases, MySQL's locking mechanism is relatively simple, and its most notable feature is that different storage engines support different locking mechanisms. For example, the MyISAM and memory storage engines use

CREATE TABLE tab2 as (SELECT * from TAB1)The storage engine for this practice table also uses the server's default storage engine instead of the source table's storage engine, which copies the contents of the table together.CREATE talbe tab2

If we want to display the line number of the MySQL table in the query, here we need to define a variable in the query statement. Because MySQL does not have a dedicated function to display line numbers , this is not like the rownum in OracleFirst

Job required to change all the MySQL table engines to InnoDBExecute the following SQLSET @DATABASE_NAME = ' name_of_your_db ';SELECT CONCAT (' ALTER TABLE ', table_name, ' engine=innodb; ') As Sql_statementsFrom Information_schema.tables as TBWHERE

Scenario: The company recently in the database from Oracle to MySQL, because the table name is not case-sensitive in Oracle, so there is no table in MySQL problem, the Internet query, found in Linux MySQL table name is case-sensitive, However, there

Scenario: The company recently in the database from Oracle to MySQL, because the table name is not case-sensitive in Oracle, so there is no table in MySQL problem, the Internet query, found in Linux MySQL table name is case-sensitive, However, there

Parse the cause of fragmentation in the mysql table and clear it. A large amount of data deletion will inevitably lead to discontinuous blank spaces in the data file. when inserting data, these blank spaces will be used. If a storage engine breaks

Considerations for mysql table design time fields: I haven't worked on the jdbc coding and database table design of mysql for a few years. I just got started and found it was a problem during the test. here I am referring to the design problem of

Requirements Scenario: There is a business database, using the MySQL 5.5 version, write a large amount of data each day, you need to either regularly delete the "specified period before" data in multiple tables, it is easy to implement in SQL

ORM The MySQL table structure is a two-dimensional table, which is represented by a Python data structure as a list, and each record is a tuple. As shown below: [(' 1 ', ' Huangyi '), (' 2 ', ' Letian '), (' 3 ', ' Xiaosi ')] This line is not easy

MySQL table connection 1. internal join Syntax: SELECT ... FROM join_table [INNER] JOIN join_table2 [ON join_condition] WHERE where_definition Only data rows that match the connection conditions in these connection tables are listed.

When creating a Mysql table, the DATE and TIME types supported by mysql (5.5) include DATETIME, TIMESTAMP, DATE, TIME, and YEAR. Comparison of several types is as follows: Date and time type Occupied space Date format Minimum

Table A {id, userId, logTime} Table B {id, userId, dimension mentid, updateTime} Table A is the data record Table B, which is equivalent to the historical record table (dimension mentid of userId before updateTime) currently, table A is associated

In Mysql, Table 'XXX' ismarkedascrashedandlast (automatic ?) Solution: the following error occurs in the MYSQL database of the website: Table './dede_archives' is marked as crashed and last (automatic ?) This problem occurs when the related table

Mysql table sharding scenario analysis and simple table sharding operations Why table sharding? First of all, you must know the situations where table sharding requires you to use table sharding when the number of records in a single table reaches