Re: [PROPOSAL] PersistentFactory performance improvement

Going once, going twice.....

> All,
> 
> We have seen that in certain situations the Persistent factory (PF) 
> components, for both default persistence and Hibernate, are being 
> created many, many times.  These are heavyweight components, with a 
> large penalty in CPU time and memory, whenever instantiated. 
>  Currently, these are pooled components, but even so, too many are 
> being created.  The proposal is to modify these two components to 
> become singletons, as they originally were before securable 
> persistents came to be. 
> 
> The downside of it is that this requires an  API change.  Currently, 
> to check authorization, the PFs keep a copy of the user context (or, 
> session, in Hibernate).  However, this makes it not possible for the 
> PF to be a singleton, since you need a copy per user.  Instead, we 
> can supply the context whenever a securable persistent needs to be 
> created.  In other words, we currently do:
> 
> Persistent p = pf.create("myschema.mypersistent");
> Persistent p = pf.create("myschema.mypersistent", transaction);
> 
> Instead, we will do:
> 
> Persistent p = pf.create("myschema.mypersistent", context);
> Persistent p = pf.create("myschema.mypersistent", transaction, 
> context);
> 
> This will change users' current code, but only if secured 
> persistents are being used.  For "regular" persistents, the old API 
> will still work.
> 
> The huge performance and memory usage gains are likely worth the 
> backwards-incompatible API change, but feedback appreciated on if 
> this is palatable to all who will be affected by the change!
> 
> Shash
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