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https://dev.mysql.com/doc/mysql-cluster-manager/8.4/en/mcm-attribute-tables-mysqld.html
ndb-default-column-format: Use this value (FIXED or DYNAMIC) by default for COLUMN_FORMAT and ROW_FORMAT options when creating or adding table columns. ndb_read_backup: Enable read from any replica for all NDB tables; use NDB_TABLE=READ_BACKUP={0|1} ...ndb-distribution: Default distribution for new tables in NDBCLUSTER (KEYHASH or LINHASH, default is ...
https://dev.mysql.com/doc/relnotes/mysql/8.4/en/news-8-4-0.html
In this release, the use of any such columns in the proposed partitioning key is now expressly disallowed, and causes the CREATE TABLE or ALTER TABLE statement in which it occurs to be rejected with an error. Attempting to use these together in ...
https://dev.mysql.com/doc/refman/8.4/en/load-data.html
If you use LOAD DATA on an empty MyISAM table, all nonunique indexes are created in a separate batch (as for REPAIR TABLE). In some extreme cases, you can create the indexes even faster by turning them off with ALTER TABLE ... DISABLE KEYS before ...
https://dev.mysql.com/doc/heatwave/en/mys-hw-genai-rag.html
The examples in this topic use the vector store table demo_embeddings created in the section Ingesting Files Using the URI with Asynchronous Load. However, vector store tables created using earlier versions of MySQL only support semantic search. To ...As of MySQL 9.2.1, for context retrieval, the ML_RAG routine uses the name of the embedding model used to embed the input query to find relevant vector store tables that contain vector embeddings from the same embedding ...
https://dev.mysql.com/doc/refman/8.4/en/derived-tables.html
The JSON_TABLE() function generates a table and provides another way to create a derived table: SELECT * FROM JSON_TABLE(arg_list) [AS] tbl_name ... For information about lateral derived tables preceded by the LATERAL keyword, see Section 15.2.15.9, ...This does not work: SELECT AVG(SUM(column1)) FROM t1 GROUP BY column1; However, this query provides the desired information: SELECT AVG(sum_column1) FROM (SELECT SUM(column1) AS sum_column1 FROM t1 GROUP BY column1) AS t1; Notice that the column name used within the subquery (sum_column1) is recognized in the outer ...
https://dev.mysql.com/doc/refman/8.4/en/innodb-online-ddl-performance.html
Session 1: mysql> CREATE TABLE t1 (c1 INT) ENGINE=InnoDB; mysql> START TRANSACTION; mysql> SELECT * FROM t1; The session 1 SELECT statement takes a shared metadata lock on table t1. Online DDL improves several aspects of MySQL operation: ...Reduced ...
https://dev.mysql.com/doc/refman/8.4/en/information-functions.html
This function can be used for the default value of a VARCHAR or TEXT column, as shown in the following CREATE TABLE statement: CREATE TABLE t (c VARCHAR(288) DEFAULT (CURRENT_USER())); DATABASE() Returns the default (current) database name as a ...
https://dev.mysql.com/doc/refman/8.4/en/innodb-auto-increment-handling.html
To make this clear, consider an example that uses this table: CREATE TABLE t1 ( c1 INT(11) NOT NULL AUTO_INCREMENT, c2 VARCHAR(10) DEFAULT NULL, PRIMARY KEY (c1) ) ENGINE=InnoDB; Suppose that there are two transactions running, each inserting rows ... InnoDB provides a configurable locking mechanism that can significantly improve scalability and performance of SQL statements that add rows to tables with AUTO_INCREMENT ...
https://dev.mysql.com/doc/refman/8.4/en/performance-schema-stage-tables.html
The Performance Schema instruments stages, which are steps during the statement-execution process, such as parsing a statement, opening a table, or performing a filesort operation. Stages correspond to the thread states displayed by SHOW ...Within ...
https://dev.mysql.com/doc/refman/8.4/en/explain.html
The SHOW CREATE TABLE, SHOW TABLE STATUS, and SHOW INDEX statements also provide information about tables. In practice, the DESCRIBE keyword is more often used to obtain information about table structure, whereas EXPLAIN is used to obtain a query ...