https://dev.mysql.com/mysql-cluster-limitations-transactions.html
Unique key reads have their locks upgraded automatically by NDB to ensure a self-consistent read; BLOB reads also employ extra locking for consistency. You can help minimize issues with shared read locks by avoiding queries that use unique key ... A ...
https://dev.mysql.com/mysqlslap.html
--auto-generate-sql-unique-write-number How many different queries to generate for --auto-generate-sql-write-number --auto-generate-sql-write-number How many row inserts to perform on each thread --commit How many statements to execute before ...
https://dev.mysql.com/sql-mode.html
ONLY_FULL_GROUP_BY Reject queries for which the select list, HAVING condition, or ORDER BY list refer to nonaggregated columns that are neither named in the GROUP BY clause nor are functionally dependent on (uniquely determined by) GROUP BY columns.
https://dev.mysql.com/audit-log-file-formats.html
The MySQL server calls the audit log plugin to write an audit record to its log file whenever an auditable event occurs. Typically the first audit record written after plugin startup contains the server description and startup options. Elements ...
https://dev.mysql.com/create-table-check-constraints.html
Consequently, CHECK constraint names must be unique per schema; no two tables in the same schema can share a CHECK constraint name. (Exception: A TEMPORARY table hides a non-TEMPORARY table of the same name, so it can have the same CHECK constraint ... Prior to MySQL 8.0.16, CREATE TABLE permits only the following limited version of table CHECK constraint syntax, which is parsed and ignored: CHECK (expr) As of MySQL 8.0.16, CREATE TABLE permits the core features of table and column CHECK constraints, for all storage ...
https://dev.mysql.com/create-table-foreign-keys.html
NDB requires an explicit unique key (or primary key) on any column referenced as a foreign key. If the CONSTRAINT symbol clause is given, the symbol value, if used, must be unique in the database. However, the system does not enforce a requirement ... MySQL supports foreign keys, which let you cross-reference related data across tables, and foreign key constraints, which help keep this spread-out data ...
https://dev.mysql.com/group-replication-configuring-instances.html
server_id=1 gtid_mode=ON enforce_gtid_consistency=ON binlog_checksum=NONE These settings configure the server to use the unique identifier number 1, to enable Section 17.1.3, “Replication with Global Transaction Identifiers”, to allow execution ... This section explains the configuration settings required for MySQL Server instances that you want to use for Group ...
https://dev.mysql.com/information-functions.html
Every connection has an ID that is unique among the set of currently connected clients. It may be used to time how quickly MySQL processes the expression. The result value is 0, or NULL for inappropriate arguments such as a NULL or negative repeat ...
https://dev.mysql.com/innodb-analyze-table-complexity.html
For the nonunique indexes, the primary key columns (a,b) are counted in addition to the user defined columns. ANALYZE TABLE complexity for InnoDB tables is dependent on: The number of pages sampled, as defined by ...
https://dev.mysql.com/innodb-fulltext-index.html
InnoDB uses a unique document identifier referred to as a Document ID (DOC_ID) to map words in the full-text index to document records where the word appears. InnoDB creates a hidden FTS_DOC_ID column along with a unique index (FTS_DOC_ID_INDEX) on ... FULLTEXT indexes are created on text-based columns (CHAR, VARCHAR, or TEXT columns) to help speed up queries and DML operations on data contained within those columns, omitting any words that are defined as ...