For research purpose, I think that expression index is a good idea. I just want to do a proof of concept.
The other issue is that my algorithm break a z-order interval into several intervals that represents the query box. How should I create it without creating any overhead?
On Mon, Aug 9, 2010 at 5:31 PM, Daniel Oliveira <danielmarquesoliveira@gmail.com> wrote: > I don't need to change B-tree estructure. I just need integrate my encode > function that transforms multiple keys into one key by bit-interleaving and > to acess elements given several intervals (range search).
You could build a "expression" index on the function which will build a regular btree. Then any range clause on a similar expression in the query would be able to use the index. Postgres is capable of detecting multiple range clauses that can use one or more indexes and combine the results. It might not be perfect for your use case, being a general purpose tool.
I'm not sure how feasible it would be to implement a special purpose case that matches your needs. Perhaps a special index type and index access method similar to gist "tsquery" data type. But that's a lot more work and a lot more C coding.