tree a4f806fe7972490da7e906920d13ea7136eba6b2
parent c5a0a1974d36d647a22d606d53bdaafd85f641df
author luochen01 <cluo8@uci.edu> 1511810041 -0800
committer Luo Chen <cluo8@uci.edu> 1511817532 -0800

[ASTERIXDB-2149] Enable multiple normalized keys in sort

- user model changes: no
- storage format changes: no
- interface changes: yes. The interface of sort is changed.

Currently, during the (in-memory) sort, we use an int normalized keys to
speed up comparisions by avoiding random memory accesses. However, this
technique is inefficient if the first 4 bytes of the sorting keys are
not distinctive. From performance point of view, it's better to use
longer normalized keys when it's possible (2-3x improvements).

This is enabled by this patch by:
- Allowing multiple normalized keys during sort, and the length of each
normalized key can be longer (multiple integers).
- Enable memory budgeting of pointer directories as well during sort
(but for performance, we still use int[], instead of byte[] from frame).

The next patch will enable the AsterixDB layer to use this feature to
speed up sort performance.

Change-Id: I4354242ff731b4b006b8446b58f65873047dde78
Reviewed-on: https://asterix-gerrit.ics.uci.edu/2127
Sonar-Qube: Jenkins <jenkins@fulliautomatix.ics.uci.edu>
Tested-by: Jenkins <jenkins@fulliautomatix.ics.uci.edu>
Contrib: Jenkins <jenkins@fulliautomatix.ics.uci.edu>
Integration-Tests: Jenkins <jenkins@fulliautomatix.ics.uci.edu>
Reviewed-by: abdullah alamoudi <bamousaa@gmail.com>