:original_name: ddm-08-0013.html .. _ddm-08-0013: Use Constraints =============== - Triggers - Temporary tables - DO statement - Association with foreign keys - RESET statement - FLUSH statement - BINLOG statement - HANDLER statement - SHOW WARNINGS statement - Assignment operator := - Operators less than (<), assignment (=), and more than (>) - Expression IS UNKNOWN - INSTALL and UNINSTALL PLUGIN statements - Cross-shard stored procedures and custom functions - Statements for modifying database names, table names, and sharding field names and types - Most of SHOW statements such as SHOW PROFILES and SHOW ERRORS - Table maintenance statements, including ANALYZE, CHECK, CHECKSUM, OPTIMIZE, and REPAIR TABLE - Statements for assigning a value to or querying variable **session**, for example, set @rowid=0;select @rowid:=@rowid+1,id from user - SQL statements that use -- or /*...*/ to comment out a single line or multiple lines of code - The result of the REPEAT function contains a maximum of 1,000,000 characters (in version 3.0.9 or later). Permission Levels ----------------- - Global level (not supported) - Database level (supported) - Table level (supported) - Column level (not supported) - Subprogram level (not supported) - User level (supported)