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https://dev.mysql.com/doc/refman/8.4/en/mysql-cluster-ndbinfo.html
row *************************** Engine: MEMORY Support: YES Comment: Hash based, stored in memory, useful for temporary tables Transactions: NO XA: NO Savepoints: NO *************************** 2. row *************************** Engine: InnoDB ...
https://dev.mysql.com/doc/refman/8.4/en/optimization-indexes.html
You must find the right balance to achieve fast queries using the optimal set of indexes. The best way to improve the performance of SELECT operations is to create indexes on one or more of the columns that are tested in the query. The index ...
https://dev.mysql.com/doc/refman/8.4/en/optimize-blob.html
For a table with several columns, to reduce memory requirements for queries that do not use the BLOB column, consider splitting the BLOB column into a separate table and referencing it with a join query when needed. Rather than testing for equality ... When storing a large blob containing textual data, consider compressing it ...
https://dev.mysql.com/doc/refman/8.4/en/optimizer-statistics.html
The column_statistics data dictionary table stores histogram statistics about column values, for use by the optimizer in constructing query execution plans. The column_statistics table has these characteristics: The table contains statistics for ...
https://dev.mysql.com/doc/refman/8.4/en/optimizing-subqueries.html
See also Section 10.2.2, “Optimizing Subqueries, Derived Tables, View References, and Common Table Expressions”. Development is ongoing, so no optimization tip is reliable for the long term. The following list provides some interesting tricks ...
https://dev.mysql.com/doc/refman/8.4/en/out-of-memory.html
Is it reasonable that it should return so many rows? If not, correct the query and try again. This causes it to use the mysql_use_result() C API function to retrieve the result set, which places less of a load on the client (but more on the server).
https://dev.mysql.com/doc/refman/8.4/en/packet-too-large.html
You can increase this if the server needs to handle big queries (for example, if you are working with big BLOB columns). A communication packet is a single SQL statement sent to the MySQL server, a single row that is sent to the client, or a binary ...
https://dev.mysql.com/doc/refman/8.4/en/partitioning-list.html
List partitioning in MySQL is similar to range partitioning in many ways. As in partitioning by RANGE, each partition must be explicitly defined. The chief difference between the two types of partitioning is that, in list partitioning, each ...
https://dev.mysql.com/doc/refman/8.4/en/performance-schema-processlist-table.html
This implementation queries active thread data from the Performance Schema rather than the thread manager and does not require a mutex. The MySQL process list indicates the operations currently being performed by the set of threads executing within ...
https://dev.mysql.com/doc/refman/8.4/en/performance-schema-statement-digests.html
For example, table columns that show wait times, lock times, or index use may highlight types of queries that are inefficient. The MySQL server is capable of maintaining statement digest information. The digesting process converts each SQL ...