Hello Hackers, Please check this out,
It is an access method to scan a table sorting by the second column of an index, filtered on the first. Queries like SELECT x, y FROM grid WHERE x in (array of Nx elements) ORDER BY y, x LIMIT M Can execute streaming the rows directly from disk instead of loading everything. Using btree index on (x, y) On a grid with N x N will run by fetching only what is necessary A skip scal will run with O(N * Nx) I/O, O(N x Nx) space, O(N x Nx * log( N * Nx)) comput (assuming a generic in memory sort) The proposed access method does it O(M + Nx) I/O, O(Nx) space, and O(M * log(Nx)) compute. Kind Regards, Alexandre Felipe Research & Development Engineer
btree_merge_rebased.patch
Description: btree_merge_rebased.patch
