Which dialect to use for DB2 on z/OS

I wonder which dialect to use for a DB2 v12 running on z/OS. There is a DB2Dialect and there is a DB2390Dialect. The DB2390 extends the DB2 one. I tried the s390 and wondered that the dialect didn’t support sequences while the DB does support them. As far as I know the DB2 runs on multiple platforms and is actually a different database. I couldn’t find any IBM committer here to provide details. What’s your experience? Which one is the best?

For now, the DB2390Dialect is probably the most appropriate. In Hibernate 6 we fixed quite a few of the missing features by introducing a DB2zDialect. If you want sequence support, you should extend the dialect and override the appropriate methods.