[elephant-devel] Elephant Collections

[Waldo Rubinstein]

Hi again,

I'm interested in learning about the collections supported by Elephant.

I have a need to store [very large] "flat" collections. For example,  
I want to store 2 million objects of approximately 1K bytes in size,  
ordered by date (an object attribute).

The only reference to collections in Elephant I have seen is the  
tutorial using btrees and indexed-btrees. What will happen when I  
load this many objects in a btree. When I get a hold of the  
persistent btree, will it keep everything in memory or will it read  
in memory the objects that I fetch from it?

Also, I have another case. I have to store about 100 objects where  
each of these objects has a reference to a collection of other  
objects. The sub-collection of objects don't need to be in any  
particular sort sequence. I was thinking of using a resizable vector.  
However, I was wondering the same questions as above. If I fetch one  
of the 100 objects, will it automatically load in memory all the  
objects in its sub-collection? The sub-collection objects may be  
30,000 elements of approximately 1K bytes in size as well. How will  
it behave if I need to traverse the sub-collection of objects of a  
particular object? Will it, again, load all the elements in memory or  
will it read from DB as needed?

Thanks,
Waldo