Unsupported Objects and 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 (<), equal sign (=), and greater than (>)
Expression IS UNKNOWN
INSTALL and UNINSTALL PLUGIN statements
Cross-shard stored procedures and custom functions
Modifying database names and sharding field names and types is not allowed.
Most of SHOW statements such as SHOW PROFILES and SHOW ERRORS
Table maintenance statements, including CHECK, CHECKSUM, OPTIMIZE, and REPAIR TABLE
Statements for assigning a value to or querying variable session
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).