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https://dev.mysql.com/doc/refman/8.4/en/optimizing-queries-myisam.html
For MyISAM tables that change frequently, try to avoid all variable-length columns (VARCHAR, BLOB, and TEXT). The table uses dynamic row format if it includes even a single variable-length column. The only cases where splitting up a table makes an ... Some general tips for speeding up queries on MyISAM tables: To help MySQL better optimize queries, use ANALYZE TABLE or run myisamchk --analyze on a table after it has been loaded with ...
https://dev.mysql.com/doc/refman/8.4/en/performance-schema-instrument-naming.html
Idle Instrument Elements The idle instrument is used for idle events, which The Performance Schema generates as discussed in the description of the socket_instances.STATE column in Section 29.12.3.5, “The socket_instances Table”. The TIMED ...
https://dev.mysql.com/doc/refman/8.4/en/replication-features-row-searches.html
Any index where the before-image of the row event does not contain all the columns of the index. A unique index where every column in the index has a NOT NULL attribute. If the algorithm is able to select a primary key or a unique index where every ... When a replica using row-based replication format applies an UPDATE or DELETE operation, it must search the relevant table for the matching ...
https://dev.mysql.com/doc/refman/8.4/en/show-replicas.html
Statement output includes this column only if the source server is started with the --show-replica-auth-info option. Statement output includes this column only if the source server is started with the --show-replica-auth-info option. A zero in this ... SHOW REPLICAS Displays a list of replicas currently registered with the ...
https://dev.mysql.com/doc/refman/8.4/en/subquery-materialization.html
Materialization speeds up query execution by generating a subquery result as a temporary table, normally in memory. Assume that where_condition involves columns only from t2 and not t1 so that the subquery is noncorrelated. The optimizer uses ...
https://dev.mysql.com/doc/refman/8.4/en/subquery-optimization-with-exists.html
Table-condition generator: If the subquery is a join of several tables, the triggered condition is checked as soon as possible. In EXPLAIN output, the fallback shows up as Full scan on NULL key in the Extra column: mysql> EXPLAIN SELECT t1.col1, ...
https://dev.mysql.com/doc/relnotes/connector-j/en/news-8-0-24.html
(Bug #32526663, Bug #102188) When using Connector/J 8.0.23, ResultSetMetaData.getColumnClassName() did not return the correct class name corresponding to DATETIME columns. (Bug #32405590, Bug #102321) Creation of an UpdatableResultSet failed with a ... Version 8.0.24 is the latest General Availability release of the 8.0 series of MySQL ...
https://dev.mysql.com/doc/relnotes/mysql-shell/9.5/en/news-9-5-0.html
(Bug #38377905) When dumping with ocimds: true, schemas and tables with ENCRYPTION disabled were updated and reported as modified, creating logging noise, even though MySQL HeatWave Service disallows enabling the statement and does not generate ...
https://dev.mysql.com/doc/x-devapi-userguide/en/working-with-sql-result-sets.html
When you execute an SQL operation on a Session using the sql() method, an SqlResult is returned. Iterating over an SqlResult is identical to working with results from CRUD operations. An SqlResult combines a result set produced by, for example, ...
https://dev.mysql.com/doc/connectors/en/connector-net-entityframework-core-charset.html
Modifications made to the model affect the tables and columns generated from your code. In the following example, the ComplexKey class represents an entity (or table) and Key1, Key2, and CollationColumn represent entity properties (or columns).