In PostgreSQL byte array column (bytea) does not have length parameter. When schema is automatically generaed, it will be correctly generated as bytea. However, during schema update length value from column metadata will be compared with either default value or value from @Column annotation (if present). This will, most likely rhan not, cause alter SQL command to be executed. Data type in this generated command will be exactly the same as one use for table creation. In most cases this will have no effect (except waste of time if PostgreSQL is not “smart” enough to ignore column data type change) but in some situations can cause problems. For example when column is used in view definition.