Search Results
https://dev.mysql.com/doc/relnotes/mysql/8.4/en/news-8-4-3.html
(Bug #36723117) InnoDB: FTS index optimization would sometimes not function correctly with tokens equal in collation order but different in terms of bytes. (Bug #36652127) InnoDB: Replaced std::this_thread::sleep_for(std::chrono::seconds(0)) usage ... C API Notes Compilation Notes Configuration Notes SQL Function and Operator Notes JavaScript Programs sys Schema Notes Thread Pool Notes Functionality Added or Changed Bugs Fixed C API Notes The asynchronous interface used unsafe static local variables to store state ...
https://dev.mysql.com/doc/mysql-cluster-manager/8.4/en/mcm-attribute-tables-mysqld.html
ndb-optimization-delay: Number of milliseconds to wait between processing sets of rows by OPTIMIZE TABLE on NDB tables. ndb_optimized_node_selection: Determines how SQL node chooses cluster data node to use as transaction coordinator.
https://dev.mysql.com/doc/internals/en/x-protocol-use-cases-use-cases.html
Optimizing for Network Round-Trips (Assuming the MySQL Client/Server Protocol in this case) Network round-trips can be minimized by creating a huge SQL statements of up to 1Gbyte in chunks of 16Mbyte (the protocol's maximum frame size) and sending ... Topics in this section: Prepared Statements with Single Round-Trip Streaming Inserts SQL with Multiple Resultsets Inserting CRUD Data in a Batch Cross-Collection Update and Delete Prepared Statements with Single Round-Trip In the MySQL Client/Server Protocol, a PREPARE/EXECUTE cycle required two round-trips as the COM_STMT_EXECUTE requires data from the COM_STMT_PREPARE-ok ...
https://dev.mysql.com/doc/mysql-monitor/8.0/en/mem-features-qrti.html
Reading QRTi Values The queries listed on the Query Analyzer page also have a color-coded pie chart representing a breakdown of the values used in the QRTi calculation; green representing the optimal percentage, yellow the acceptable percentage, and ...It is a "quality of service" measurement for each query, and uses the Apdex formula for that calculation: Apdex on ...
https://dev.mysql.com/doc/heatwave/en/mys-hw-debugging-queries.html
Query debugging is performed by enabling MySQL optimizer trace and querying the INFORMATION_SCHEMA.OPTIMIZER_TRACE table for the failure reason. To enable MySQL optimizer trace, set the optimizer_trace and optimizer_trace_offset variables as shown: ... This section describes how to debug queries that fail to offload to HeatWave for ...
https://dev.mysql.com/doc/refman/8.4/en/alter-table-partition-operations.html
These include ANALYZE PARTITION, CHECK PARTITION, OPTIMIZE PARTITION, REBUILD PARTITION, and REPAIR PARTITION. OPTIMIZE PARTITION causes the entire table to rebuilt and analyzed, and an appropriate warning to be issued. The ANALYZE PARTITION, CHECK ... Partitioning-related clauses for ALTER TABLE can be used with partitioned tables for repartitioning, to add, drop, discard, import, merge, and split partitions, and to perform partitioning ...
https://dev.mysql.com/doc/refman/8.4/en/archive-storage-engine.html
You can use OPTIMIZE TABLE to analyze the table and pack it into a smaller format (for a reason to use OPTIMIZE TABLE, see later in this section). To achieve better compression, you can use OPTIMIZE TABLE or REPAIR TABLE. See Section 15.7.3.4, ...
https://dev.mysql.com/doc/refman/8.4/en/derived-tables.html
The optimizer determines information about derived tables in such a way that EXPLAIN does not need to materialize them. See Section 10.2.2.4, “Optimizing Derived Tables, View References, and Common Table Expressions with Merging or ...For ...
https://dev.mysql.com/doc/refman/8.4/en/index-btree-hash.html
Any index that does not span all AND levels in the WHERE clause is not used to optimize the query. WHERE index=1 OR A=10 AND index=2 /* optimized like "index_part1='hello'" */ ... One circumstance under which this occurs is when the optimizer ...
https://dev.mysql.com/doc/refman/8.4/en/information-functions.html
The former involves the parser, optimizer, table locking, and runtime evaluation N times each. Memory structures already allocated are reused, and runtime optimizations such as local caching of results already evaluated for aggregate functions can ...It may be used to time how quickly MySQL processes the ...