Mysql persistence error with datatype "String"


there is a problem with mysql persistence and String type (openhab 2.1):

[sql.internal.MysqlPersistenceService] - mySQL: Could not create table for item ‘hmt_val_alert_smde_05’ with statement ‘CREATE TABLE Item145 (Time DATETIME, Value VARCHAR(20000), PRIMARY KEY(Time));’: Column length too big for column ‘Value’ (max = 16383); use BLOB or TEXT instead

Where can the create statement be adjusted?

Thanks in advance.

The docs appear to indicate you can tweak the length in the configuration.