Index Cache Depth

I’d like some clarification on the new Index Cache Depth feature of the GetEventStore version 3.2.0 and above. I’ve read the developer blog entry that indicates that it can be used to make the GetEventStore improve performance but I’m am unclear as to what values might be useful here. All I read is the following:

  • #623 - (All Platforms) - Index cache depth can now be specified. This can significantly improve performance when working with large databases
  • -IndexCacheDepth or --index-cache-depth=VALUE | INDEX_CACHE_DEPTH | IndexCacheDepth = Sets the depth to cache for the mid point cache in index. (Default: 16)
    Can you maybe make another blog entry or please explain what values might be helpful and in what situations? “Big” is too ambiguous as what is big to you might not be big to me etc. Can you give an example of what the index should be for say a 20 or 30 chunk event store? 40 chunk etc? From what I can tell this might make the event store faster reading and querying if I could just understand the feature better.

Thank you.

These are fine with defaults. Its only needed when you start talking about billions of events (e.g. say a 1tb database or higher).

OK. Let’s talk tb’s then. At what point does this become useful?

Its more about number of events. 4096/20 * 2 ^ 17 IIRC