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https://dev.mysql.com/doc/refman/9.7/en/descending-indexes.html
For InnoDB full-text search, this means that the index required on the FTS_DOC_ID column of the indexed table cannot be defined as a descending index. MySQL supports descending indexes: DESC in an index definition is no longer ignored but causes ...
https://dev.mysql.com/doc/refman/9.7/en/drop-database.html
DROP {DATABASE | SCHEMA} [IF EXISTS] db_name DROP DATABASE drops all tables in the database and deletes the database. To keep this from happening, ensure that all tables in the database use a storage engine that supports atomic DDL (see Section ...
https://dev.mysql.com/doc/refman/9.7/en/environment-variables.html
This section lists environment variables that are used directly or indirectly by MySQL. Most of these can also be found in other places in this manual. Options on the command line take precedence over values specified in option files and ...
https://dev.mysql.com/doc/refman/9.7/en/faqs-information-schema.html
Can I add to or otherwise modify the tables found in the INFORMATION_SCHEMA database? A.7.1. Where can I find documentation for the MySQL INFORMATION_SCHEMA database? See Chapter 28, INFORMATION_SCHEMA Tables. What is the difference between the ...
https://dev.mysql.com/doc/refman/9.7/en/faqs-tablespace-encryption.html
Does the transportable tablespaces feature work with InnoDB data-at-rest encryption? A.17.12. How do I migrate data from a cleartext InnoDB tablespace to an encrypted InnoDB tablespace? A.17.1. It uses Electronic Codebook (ECB) block encryption mode ...Is data decrypted for users who are authorized to see it? ...
https://dev.mysql.com/doc/refman/9.7/en/foreign-key-optimization.html
If a table has many columns, and you query many different combinations of columns, it might be efficient to split the less-frequently used data into separate tables with a few columns each, and relate them back to the main table by duplicating the ...Depending on how the data is distributed, the queries might perform less I/O and take up less cache memory because the relevant columns are packed together on ...
https://dev.mysql.com/doc/refman/9.7/en/group-by-modifiers.html
The GROUP BY clause permits a WITH ROLLUP modifier that causes summary output to include extra rows that represent higher-level (that is, super-aggregate) summary operations. ROLLUP thus enables you to answer questions at multiple levels of ...
https://dev.mysql.com/doc/refman/9.7/en/group-replication-requirements.html
Convert any tables in other storage engines to use InnoDB before using the instance with Group Replication. Every table that is to be replicated by the group must have a defined primary key, or primary key equivalent where the equivalent is a ...
https://dev.mysql.com/doc/refman/9.7/en/innodb-index-types.html
Each InnoDB table has a special index called the clustered index that stores row data. When you define a PRIMARY KEY on a table, InnoDB uses it as the clustered index. If you do not define a PRIMARY KEY for a table, InnoDB uses the first UNIQUE ...
https://dev.mysql.com/doc/refman/9.7/en/innodb-information-schema-innodb_cmp.html
The INNODB_CMP and INNODB_CMP_RESET tables provide status information about operations related to compressed tables, which are described in Section 17.9, “InnoDB Table and Page Compression”. These two tables have identical contents, but reading ...For example, if you archive the output of INNODB_CMP_RESET every 60 minutes, you see the statistics for each hourly ...