14.10. The EXAMPLE Storage Engine

The EXAMPLE storage engine is a stub engine that does nothing. Its purpose is to serve as an example in the MySQL source code that illustrates how to begin writing new storage engines. As such, it is primarily of interest to developers.

To enable the EXAMPLE storage engine if you build MySQL from source, invoke CMake with the -DWITH_EXAMPLE_STORAGE_ENGINE option.

To examine the source for the EXAMPLE engine, look in the storage/example directory of a MySQL source distribution.

When you create an EXAMPLE table, the server creates a table format file in the database directory. The file begins with the table name and has an .frm extension. No other files are created. No data can be stored into the table. Retrievals return an empty result.

mysql> CREATE TABLE test (i INT) ENGINE =
        EXAMPLE;Query OK, 0 rows affected (0.78 sec)mysql> INSERT
        INTO test VALUES(1),(2),(3);ERROR 1031 (HY000): Table storage engine for 'test' doesn't »                    have this optionmysql> SELECT * FROM test;Empty set (0.31 sec)

The EXAMPLE storage engine does not support indexing.