DDM is compatible with the MySQL license and syntax, but the use of SQL statements is limited due to differences between distributed databases and single-node databases.
Unsupported SQL Statements
- 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
Permission levels supported by DDM are as follows:
- Global level (not supported)
- Database level (supported)
- Table level (supported)
- Column level (not supported)
- Subprogram level (not supported)
- User level (supported)