Originally posted by Roger Goerke:
This JDO seems a little too good to be true. There must be some price to pay for all the flexibility listed in the requirements.
Is JDO a performance killer? How does JDO get access to the private persistable attributes and how does JDO know that an object is dirty?
Any background info provided will be helpful for me to understand why I might consider using them over EJB.
Originally posted by Dirk Schreckmann:
This JDO seems a little too good to be true. There must be some price to pay for all the flexibility listed in the requirements.
Is JDO a performance killer? How does JDO get access to the private persistable attributes and how does JDO know that an object is dirty?
Any background info provided will be helpful for me to understand why I might consider using them over EJB.
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Originally posted by Jeanne Boyarsky:
What about the actual optimization? Some queries can't be cached (no repetition) or the performance of the initial query is horrible.
Does JDO let you optimize to use indexes? Does JDO deal on an object/row level or a field/column level?
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Originally posted by Lasse Koskela:
The JDO implementation gives you some way of mapping the Java object model into the database schema, right? Isn't this then purely a question of optimizing that schema within the database with the database vendor's tools?
As to the question about object/row vs field/column level, I believe JDO lets you deal with objects and nothing more -- the whole point is to not think about tables, rows and columns but simply objects of which state needs to be persisted.
Do I make sense?
John Takacs, DPM
Originally posted by John Takacs, D.P.M.:
If "it's all about cache", does that mean that only certain recurring queries are ever maintained in memory? In other words, an entire table would never persist?