Use Constraints

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)

last updated: 2024-12-11 13:43 UTC - commit: 0e04c4a111cf440cbe530f17da84f5c1ac074d8f