You are correct that SciDB arrays are separated into chunks. The chunks are formed based on the chunk size parameter for each dimension in the array schema. Choosing an appropriate chunk size for an array can sometimes be tricky, which is why P4 has developed tools to help automate the process. For more information, check out the tutorial video:
SciDB doesn’t really use the concept of a segment. Chunks are distributed to different instances based on a hash function and the level of replication requested in the config.ini file. I’m not quite sure what you mean by whether the distribution algorithm is “polling”… the replication is synchronous, if that is what you mean. The replication is guaranteed to be complete once the store transaction is committed.
As far as node failure is concerned, if you have purchased the Enterprise Edition of SciDB, node failures are detected and data is read from replica nodes transparently, so it does not need to be reloaded. This feature is not supported in the Community Edition, however.
Finally, regarding consistent hashing, SciDB does not currently support adding nodes to an existing cluster. Therefore, consistent hashing is not really relevant.
Hope this information helps…
Thank you for your reply, and I have the last question:
regarding the partition strategy, what’s the SciDB’s partition algorithm ?