[elephant-devel] Re: BDB vs postmodern

[Ian Eslick]

> the solution seems to be trivial: implement caching on a client  
> side. simple
> solution is to cache data within single transaction. complex  
> solution is to
> cache data accross transaction, tracking changes and invalidating  
> stale
> cache entries automatically.
>
> we've implemented both options. so now it's possible to have all slots
> cached on a Lisp side. as long as there are much more reads than  
> writes
> (which is common for web applications, for example), strain on a  
> database is
> significantly decreased. all index queries (select object by value  
> or by
> range) still work via database, but typically there's much more slot  
> queries
> than index queries.
>

Is this caching something that we could import into BDB?  There are  
certainly occasions for caching slot values as well as object  
references.  Robert and I once talked about adding a slot policy for  
write-through caching but never got around to it...

Ian