Search Results
https://dev.mysql.com/doc/refman/8.4/en/performance-schema-summary-tables.html
Summary tables provide aggregated information for terminated events over time. The tables in this group summarize event data in different ways. Each summary table has grouping columns that determine how to group the data to be aggregated, and ...
https://dev.mysql.com/doc/refman/8.4/en/mysql-cluster-online-add-node-remarks.html
REORGANIZE PARTITION statement has reached the internal commit point: When the cluster is restarted, the data and indexes belonging to table are distributed using the “new” data nodes. REORGANIZE PARTITION statement has not yet reached the ...
https://dev.mysql.com/doc/refman/8.4/en/source-configuration-options.html
You can build a plugin as a static module (compiled into the server) or a dynamic module (built as a dynamic library that must be installed into the server using the INSTALL PLUGIN statement or the --plugin-load option before it can be used). If it ... The CMake program provides a great deal of control over how you configure a MySQL source ...
https://dev.mysql.com/doc/refman/8.4/en/fulltext-search.html
A FULLTEXT index definition can be given in the CREATE TABLE statement when a table is created, or added later using ALTER TABLE or CREATE INDEX. MATCH (col1,col2,...) AGAINST (expr [search_modifier]) search_modifier: { IN NATURAL LANGUAGE MODE | ...MySQL provides a built-in full-text ngram parser that supports Chinese, Japanese, and Korean (CJK), and an installable MeCab full-text parser plugin for ...
https://dev.mysql.com/doc/refman/8.4/en/optimizing-queries-myisam.html
This updates a value for each index part that indicates the average number of rows that have the same value. (For unique indexes, this is always 1.) MySQL uses this to decide which index to choose when you join two tables based on a nonconstant ...
https://dev.mysql.com/doc/ndbapi/en/ndb-start-mysql-db-object-names.html
Instead, they are modelled as attributes of Table and Index objects. The value of the database attribute of one of these objects is always the same as the name of the MySQL database to which the table or index belongs. The value of the schema ...
https://dev.mysql.com/doc/refman/8.4/en/innodb-analyze-table-complexity.html
The number of indexed columns in a table The number of partitions. Using these parameters, an approximate formula for estimating ANALYZE TABLE complexity would be: The value of innodb_stats_persistent_sample_pages * number of indexed columns in a ...
https://dev.mysql.com/doc/refman/8.4/en/innodb-next-key-locking.html
If the locks set on the index records in the scanned range do not lock out inserts made in the gaps (in this case, the gap between 90 and 102), another session can insert a new row into the table with an id of 101. To prevent phantoms, InnoDB uses ... The so-called phantom problem occurs within a transaction when the same query produces different sets of rows at different ...
https://dev.mysql.com/doc/refman/8.4/en/aggregate-functions.html
InnoDB processes SELECT COUNT(*) statements by traversing the smallest available secondary index unless an index or optimizer hint directs the optimizer to use a different index. If a secondary index is not present, InnoDB processes SELECT COUNT(*) ...If you use an aggregate function in a statement containing no GROUP BY clause, it is equivalent to grouping on all ...
https://dev.mysql.com/doc/refman/8.4/en/optimizing-innodb-bulk-data-loading.html
These performance tips supplement the general guidelines for fast inserts in Section 10.2.5.1, “Optimizing INSERT Statements”. To disable autocommit during your import operation, surround it with SET autocommit and COMMIT statements: SET ...