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https://dev.mysql.com/doc/refman/8.4/en/innodb-locking-reads.html
If you query data and then insert or update related data within the same transaction, the regular SELECT statement does not give enough protection. FOR SHARE, or from reading the data in certain transaction isolation levels. These clauses are ...
https://dev.mysql.com/doc/refman/8.4/en/information-schema-innodb-datafiles-table.html
The INNODB_DATAFILES table provides data file path information for InnoDB file-per-table and general tablespaces. Note The INFORMATION_SCHEMA FILES table reports metadata for InnoDB tablespace types including file-per-table tablespaces, general ...
https://dev.mysql.com/doc/refman/8.4/en/information-schema-innodb-buffer-page-table.html
For more information about how the InnoDB manages buffer pool data, see Section 17.5.1, “Buffer Pool”. The INNODB_BUFFER_PAGE table provides information about each page in the InnoDB buffer pool. The INNODB_BUFFER_PAGE table has these columns: ...For related usage information and examples, see Section 17.15.5, “InnoDB INFORMATION_SCHEMA Buffer Pool ...
https://dev.mysql.com/doc/refman/8.4/en/innodb-compression-background.html
Data compression enables smaller database size, reduced I/O, and improved throughput, at the small cost of increased CPU utilization. An InnoDB table created with ROW_FORMAT=COMPRESSED can use a smaller page size on disk than the configured ...
https://dev.mysql.com/doc/refman/8.4/en/information-schema-innodb-tablespaces-brief-table.html
INNODB_TABLESPACES provides the same metadata but loads more slowly because other metadata provided by the table, such as FS_BLOCK_SIZE, FILE_SIZE, and ALLOCATED_SIZE, must be loaded dynamically. The INNODB_TABLESPACES_BRIEF table provides space ...
https://dev.mysql.com/doc/refman/8.4/en/information-schema-innodb-cmp-per-index-table.html
The INNODB_CMP_PER_INDEX and INNODB_CMP_PER_INDEX_RESET tables provide status information on operations related to compressed InnoDB tables and indexes, with separate statistics for each combination of database, table, and index, to help you ...In ...Pages are compressed whenever an empty page is created or the space for the uncompressed modification log runs ...
https://dev.mysql.com/doc/refman/8.4/en/innodb-performance-compression-oltp.html
Traditionally, the InnoDB compression feature was recommended primarily for read-only or read-mostly workloads, such as in a data warehouse configuration. If you are certain that the zlib version is not subject to change, disable ...These ...The ...
https://dev.mysql.com/doc/refman/8.4/en/innodb-performance-midpoint_insertion.html
Rather than using a strict LRU algorithm, InnoDB uses a technique to minimize the amount of data that is brought into the buffer pool and never accessed again. Both innodb_old_blocks_pct and innodb_old_blocks_time can be specified in the MySQL ...
https://dev.mysql.com/doc/refman/8.4/en/information-schema-innodb-tablestats-table.html
This data is used by the MySQL optimizer to calculate which index to use when querying an InnoDB table. CLUST_INDEX_SIZE The number of pages on disk that store the clustered index, which holds the InnoDB table data in primary key order. The ...
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 ...