Hi,

Project in hand: legacy modernization of a RPG based application running on AS/400 (iSeries) and using DB2/400 database.

Proposed stack: j2EE/ Spring.... with the Hibernate ORM; but client wants to retain the same hardware AS/400 (iSeries) and DB2/400 database.

I discovered Hibernate ORM can work with db2/400 if and only if the database files are journaled.
But that would mean more disk space to store the journaled images.

So my question is;
1. Does Hibernate require both the before and after images?
2. Will Hibernate work if we limit to having only the AFTER images in the journal (as that way client can limit the investment on the extra storage space)

PS: The size of the current database (used with the legacy/ RPG based app) runs into Tera bytes.

thank you.
~g1

Hi,

After attempting a POC (sample java class, using Hibernate and the DB2/400 database), discovered that

1. With NO journaling – Database operations failed.
2. With Only AFTER image Journaling – database operation were successfully executed.
3. With BOTH image journaling - database operation were successfully executed.
4. With Only BEFORE image journaling – Not possible as DB2 does not support only BEFORE image.

But in the POC, only tried a 1-to-1 mapped table and attempted inserting into both tables.
On purpose, inserted data, to force a SQL-Exception .... the complete transaction was rolled back

So I guess CONSISTENCY was maintained.

How to check the "I" of ACID - I mean ISOLATION?
Also it does not tell me, if ONLY after-image journaling is sufficient..... please help

~g1