SHOW DATABASES
This statement shows a list of databases that the current user has privileges to. Databases which the current user does not have access to will appear hidden from the list. The information_schema database always appears first in the list of databases.
SHOW SCHEMAS is an alias of this statement.
Synopsis
ShowDatabasesStmt:

ShowLikeOrWhereOpt:

Examples
mysql> SHOW DATABASES;
+--------------------+
| Database           |
+--------------------+
| INFORMATION_SCHEMA |
| PERFORMANCE_SCHEMA |
| mysql              |
| test               |
+--------------------+
4 rows in set (0.00 sec)
mysql> CREATE DATABASE mynewdb;
Query OK, 0 rows affected (0.10 sec)
mysql> SHOW DATABASES;
+--------------------+
| Database           |
+--------------------+
| INFORMATION_SCHEMA |
| PERFORMANCE_SCHEMA |
| mynewdb            |
| mysql              |
| test               |
+--------------------+
5 rows in set (0.00 sec)
MySQL compatibility
The SHOW DATABASES statement in TiDB is fully compatible with MySQL. If you find any compatibility differences, report a bug.