This document describes the common usage limitations of TiDB, including the maximum identifier length and the maximum number of supported databases, tables, indexes, partitioned tables, and sequences.
Note
TiDB offers high compatibility with the MySQL protocol and syntax, including many MySQL limitations. For example, a single index can include a maximum of 16 columns. For more information, see MySQL Compatibility and the official MySQL documentation.
Limitations on identifier length
Identifier type
Maximum length (number of characters allowed)
Database
64
Table
64
Column
64
Index
64
View
64
Sequence
64
Limitations on the total number of databases, tables, views, and connections