Is caching worth it when my whole index is in RAM?

2009-08-31 Thread Michael
Hi,
If I've got my entire 20G 4MM document index in RAM (on a ramdisk), do I
have a need for the document cache?  Or should I set it to 0 items, because
pulling field values from an index in RAM is so fast that the document cache
would be a duplication of effort?

Are there any other caches that I should turn off if I can get my entire
index in RAM?  Filter cache, query results cache, etc?

Thanks!
Michael


Re: Is caching worth it when my whole index is in RAM?

2009-08-31 Thread Avlesh Singh
Good question!
The application level cache, say filter cache, would still help because it
not only caches values but also the underlying computation. Even with all
the data in your RAM you will still end up doing the computations every
time.

Looking for responses from the more knowledgeable.

Cheers
Avlesh

On Mon, Aug 31, 2009 at 8:25 PM, Michael  wrote:

> Hi,
> If I've got my entire 20G 4MM document index in RAM (on a ramdisk), do I
> have a need for the document cache?  Or should I set it to 0 items, because
> pulling field values from an index in RAM is so fast that the document
> cache
> would be a duplication of effort?
>
> Are there any other caches that I should turn off if I can get my entire
> index in RAM?  Filter cache, query results cache, etc?
>
> Thanks!
> Michael
>


Re: Is caching worth it when my whole index is in RAM?

2009-09-01 Thread Michael
Thanks, Avlesh!  I'll try the filter cache.
Anybody familiar enough with the caching implementation to chime in?

Michael

On Mon, Aug 31, 2009 at 10:02 PM, Avlesh Singh  wrote:

> Good question!
> The application level cache, say filter cache, would still help because it
> not only caches values but also the underlying computation. Even with all
> the data in your RAM you will still end up doing the computations every
> time.
>
> Looking for responses from the more knowledgeable.
>
> Cheers
> Avlesh
>
> On Mon, Aug 31, 2009 at 8:25 PM, Michael  wrote:
>
> > Hi,
> > If I've got my entire 20G 4MM document index in RAM (on a ramdisk), do I
> > have a need for the document cache?  Or should I set it to 0 items,
> because
> > pulling field values from an index in RAM is so fast that the document
> > cache
> > would be a duplication of effort?
> >
> > Are there any other caches that I should turn off if I can get my entire
> > index in RAM?  Filter cache, query results cache, etc?
> >
> > Thanks!
> > Michael
> >
>