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https://dev.mysql.com/doc/refman/8.4/en/ibd2sdi.html
ibd2sdi is a utility for extracting serialized dictionary information (SDI) from InnoDB tablespace files. ibd2sdi can be run on file-per-table tablespace files (*.ibd files), general tablespace files (*.ibd files), system tablespace files (ibdata* ...
https://dev.mysql.com/doc/refman/8.4/en/identifier-mapping.html
(On a case-insensitive file system, both letters are treated as the same.) For some blocks, such as Cyrillic, the second byte determines lettercase. There is a correspondence between database and table identifiers and names in the file system. For ...
https://dev.mysql.com/doc/refman/8.4/en/index-btree-hash.html
WHERE index_part2=1 AND index_part3=2 /* Index is not used in both parts of the WHERE clause */ ... Understanding the B-tree and hash data structures can help predict how different queries perform on different storage engines that use these data ...
https://dev.mysql.com/doc/refman/8.4/en/index-extensions.html
InnoDB automatically extends each secondary index by appending the primary key columns to it. Consider this table definition: CREATE TABLE t1 ( i1 INT NOT NULL DEFAULT 0, i2 INT NOT NULL DEFAULT 0, d DATE DEFAULT NULL, PRIMARY KEY (i1, i2), INDEX ...
https://dev.mysql.com/doc/refman/8.4/en/index-hints.html
These index-level optimizer hints are supported with both single-table and multi-table DELETE statements. Index hints give the optimizer information about how to choose indexes during query processing. Index hints, described here, differ from ...
https://dev.mysql.com/doc/refman/8.4/en/index-page-merge-threshold.html
If both pages are close to 50% full, a page split can occur soon after the pages are merged. If the “page-full” percentage for an index page falls below the MERGE_THRESHOLD value when a row is deleted or when a row is shortened by an UPDATE ...
https://dev.mysql.com/doc/refman/8.4/en/information-schema-innodb-buffer-pool-stats-table.html
The INNODB_BUFFER_POOL_STATS table provides much of the same buffer pool information provided in SHOW ENGINE INNODB STATUS output. Much of the same information may also be obtained using InnoDB buffer pool server status variables. The idea of ...
https://dev.mysql.com/doc/refman/8.4/en/information-schema-innodb-trx-table.html
When this column and TRX_IS_READ_ONLY are both 1, InnoDB optimizes the transaction to reduce the overhead associated with transactions that change table data. The INNODB_TRX table provides information about every transaction currently executing ...
https://dev.mysql.com/doc/refman/8.4/en/information-schema-introduction.html
Information about generated invisible primary keys is visible by default in all INFORMATION_SCHEMA tables describing table columns, keys, or both, such as the COLUMNS and STATISTICS tables. INFORMATION_SCHEMA provides access to database metadata, ...
https://dev.mysql.com/doc/refman/8.4/en/information-schema-statistics-table.html
EXPRESSION MySQL supports functional key parts (see Functional Key Parts), which affects both the COLUMN_NAME and EXPRESSION columns: For a nonfunctional key part, COLUMN_NAME indicates the column indexed by the key part and EXPRESSION is NULL. The ...