Contents
What is INFORMATION_SCHEMA tables in MySQL?
Chapter 1 INFORMATION_SCHEMA Tables INFORMATION_SCHEMA provides access to database metadata, information about the MySQL server such as the name of a database or table, the data type of a column, or access privileges. Other terms that are sometimes used for this information are data dictionary and system catalog.
What is the use of INFORMATION_SCHEMA in SQL Server?
The INFORMATION_SCHEMA database is an ANSI standard set of views we can find in SQL Server, but also MySQL. Other database systems also have either exactly such or similar database implemented. It provides the read-only access to details related to databases and their objects (tables, constraints, procedures, views…)
What is Data_length in MySQL?
DATA_LENGTH. For MyISAM , DATA_LENGTH is the length of the data file, in bytes. For InnoDB , DATA_LENGTH is the approximate amount of space allocated for the clustered index, in bytes. Specifically, it is the clustered index size, in pages, multiplied by the InnoDB page size.
What is MySQL Infoschema user?
Used internally by plugins to access the server. The user by default has an invalid password and is locked, so it cannot be used to connect to MySQL. mysql.infoschema@localhost. 8.0.4. Information Schema.
Why does MySQL not update information _ schema automatically?
The problem is the TABLES table of information_schema is not updated with the current value, unless I run the following query: Why doesn’t MySQL update information_schema automatically, and how could I fix this behavior?
When does the MySQL information schema statistics expire?
The information_schema_stats_expiry system variable defines the period of time before cached table statistics expire. The default is 86400 seconds (24 hours). If there are no cached statistics or statistics have expired, statistics are retrieved from storage engines when querying table statistics columns.
Which is the name of the schema table?
The name of the schema (database) to which the table belongs. The name of the table. BASE TABLE for a table, VIEW for a view, or SYSTEM VIEW for an INFORMATION_SCHEMA table. The TABLES table does not list TEMPORARY tables. The storage engine for the table.
What do you mean by table of contents in MySQL?
Table of Contents. INFORMATION_SCHEMA provides access to database metadata, information about the MySQL server such as the name of a database or table, the data type of a column, or access privileges. Other terms that are sometimes used for this information are data dictionary and system catalog .