OpenJPA generates incorrect CREATE TABLE statements with PostgreSQL, and you will get syntax errors.
OpenJPA adds "DEFERRABLE" to unique constraints, probably because PostgresDictionary sets "true" as "supportsDeferredConstraints", while PostgreSQL accepts "DEFERRABLE" only with foreign key constraints.
The description of "CREATE TABLE" in the PostgreSQL documents is so confusing : the syntax description at the top of the page makes us feel that "DEFERRABLE" can be specified with any table constraints, but you can find that it says "Only foreign key constraints currently accept this clause" in the middle of the page. See:
As a result of this confusion, SQL statements which OpenJPA generates result in database errors saying :
syntax error at or near "DEFERRABLE"
An example of generated SQLs is :
CREATE TABLE PUBLIC.FOO (entityId BIGINT NOT NULL,
memo TEXT, name VARCHAR(255) NOT NULL,
entityVersion INTEGER NOT NULL,
PRIMARY KEY (entityId), UNIQUE (name) DEFERRABLE);
As a workaround, you can add the following line in the persistence.xml to avoid this problem:
<property name="openjpa.jdbc.DBDictionary" value="postgres(SupportsDeferredConstraints=false)"/>