Search Results
https://dev.mysql.com/doc/internals/en/getting-index-information.html
It is preferable for storage engines that support indexing to read the index information provided during a CREATE TABLE operation and store it for future use. The reasoning behind this is that the index information is most readily available during ...
https://dev.mysql.com/doc/internals/en/myisam-directory.html
They are: mi_cache.c --- for reading records from a cache mi_changed.c --- a single routine for setting a "changed" flag (very short) mi_check.c --- for checking and repairing tables. Can be used to exactly replay a set of changes to a table.
https://dev.mysql.com/doc/heatwave/en/mys-hw-limitations-data-types.html
The following string and text data types are unsupported: BINARY VARBINARY Decimal values with a precision greater than 18 in expression operators are unsupported, with the exception of the following: Arithmetic operators, see: Section 5.3.2, ...
https://dev.mysql.com/doc/refman/8.4/en/alter-table.html
ALTER TABLE tbl_name [alter_option [, alter_option] ...] [partition_options] alter_option: { table_options | ADD [COLUMN] col_name column_definition [FIRST | AFTER col_name] | ADD [COLUMN] (col_name column_definition,...) | ADD {INDEX | KEY} ...
https://dev.mysql.com/doc/refman/8.4/en/built-in-function-reference.html
The following table lists each built-in (native) function and operator and provides a short description of each one. For a table listing functions that are loadable at runtime, see Section 14.2, “Loadable Function Reference”. ->> Return value ...
https://dev.mysql.com/doc/refman/8.4/en/descending-indexes.html
MySQL supports descending indexes: DESC in an index definition is no longer ignored but causes storage of key values in descending order. Previously, indexes could be scanned in reverse order but at a performance penalty. A descending index can be ...
https://dev.mysql.com/doc/refman/8.4/en/gis-class-geometrycollection.html
A GeomCollection is a geometry that is a collection of zero or more geometries of any class. GeomCollection and GeometryCollection are synonymous, with GeomCollection the preferred type name. All the elements in a geometry collection must be in the ...
https://dev.mysql.com/doc/refman/8.4/en/group-replication-functions-for-new-primary.html
The following function enables you to set a member of a single-primary replication group to take over as the primary. The current primary becomes a read-only secondary, and the specified group member becomes the read-write primary. The function can ...
https://dev.mysql.com/doc/refman/8.4/en/implicit-commit.html
The statements listed in this section (and any synonyms for them) implicitly end any transaction active in the current session, as if you had done a COMMIT before executing the statement. Most of these statements also cause an implicit commit after ...
https://dev.mysql.com/doc/refman/8.4/en/information-schema-general-table-reference.html
The following table summarizes INFORMATION_SCHEMA general tables. For greater detail, see the individual table descriptions. Table 28.2 INFORMATION_SCHEMA General Tables Table Name Description ADMINISTRABLE_ROLE_AUTHORIZATIONS Grantable users or ...