On Thu, Nov 15, 2012 at 12:00 PM, Jukka Zitting <jukka.zitt...@gmail.com> wrote: > Hi, > > This came up earlier in the Berlin Oakathon and we're now facing it > also with the property index. Basically, do we want to add explicit > support for long (>> 1k values) multivalued properties? > > Currently such properties are possible in theory since there is no > hard limit to the size of the value array, but in practice accessing > such properties requires reading the whole array to memory and even a > simple update (like appending a single value) requires the whole array > to be rewritten. > > There are two ways of supporting use cases that require such long > multivalued properties: a) we can support it directly in the > repository, or b) we require the client to use more complex data > structures like in the BTreeManager in Jackrabbit trunk or the BTree > implementation in the wrapper-based index implementation Thomas wrote > for Oak. > > Supporting such use cases directly in the repository would be nice as > that would notably simplify affected clients. However, doing so would > require us to adapt some of our APIs. For example we'd need a way to > iterate over the list of values of a single property and to add, set > and remove individual values at specific locations. The > PropertyBuilder interface already has some of this, but neither the > Oak API nor the MicroKernel currently support such operations. > > WDYT, should we implement something along these lines or leave it up > to clients? I'm cautiously positive in that we should do this since > we'd in any case need similar code for the property index, but would > love to hear other opinions.
personally i am not aware of real life use cases requiring 'large' mv properties. since the ultimate goal of oak is to provide a JCR implementation and the JCR API doesn't provide any methods to manipulate/access single members of a mv property i don't think we need to support it under the hood. cheers stefan > > BR, > > Jukka Zitting
