Tim Armstrong has posted comments on this change. Change subject: IMPALA-4864 Speed up single slot predicates with dictionaries ......................................................................
Patch Set 16: (1 comment) http://gerrit.cloudera.org:8080/#/c/6726/16/be/src/exec/parquet-column-readers.cc File be/src/exec/parquet-column-readers.cc: Line 420: LIKELY(dictionary_results_.num_bits() > 0)) { > Not liking this branch, but it is unavoidable without pre-computation overh I think the predicate evaluation on 40,000 values is probably cheap enough to just do it. In most cases we would have to evaluate the predicates anyway when processing the dictionary-encoded pages. I don't think I fully understand the inexpensive predicate check that you're envisioning. Does it really need to be done per-row instead of per-batch (like the IS_DICT_ENCODED branch). -- To view, visit http://gerrit.cloudera.org:8080/6726 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-MessageType: comment Gerrit-Change-Id: I65981c89e5292086809ec1268f5a273f4c1fe054 Gerrit-PatchSet: 16 Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-Owner: Zach Amsden <[email protected]> Gerrit-Reviewer: Joe McDonnell <[email protected]> Gerrit-Reviewer: Marcel Kornacker <[email protected]> Gerrit-Reviewer: Michael Ho <[email protected]> Gerrit-Reviewer: Tim Armstrong <[email protected]> Gerrit-Reviewer: Zach Amsden <[email protected]> Gerrit-HasComments: Yes
