Sailesh Mukil has posted comments on this change.

Change subject: IMPALA-3804: Push per-split filtering into scanners
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Patch Set 3:

(1 comment)

> Will respond to individual comments in next patch set, but want to
 > point out that filters can arrive at any time during a scan's
 > execution. So checking early and often is what we do for now - a
 > filter that may not have applied when issuing scan ranges may have
 > arrived and be applicable at the per-row-group scope.

Ah, that makes sense. Do you think it's worth doing a multi-level check? i.e. 
once in IssueInitialRanges() and once in ProcessSplit()? Or will that not help 
us in the average case?

http://gerrit.cloudera.org:8080/#/c/3561/3/be/src/exec/base-sequence-scanner.cc
File be/src/exec/base-sequence-scanner.cc:

PS3, Line 135: stream_->scan_range()->Cancel(Status::CANCELLED);
As we spoke, this should be consistent with the other scanners, i.e. cancel 
"this" range in all scanners if necessary, or just return here like the parquet 
and text scanners do.


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Gerrit-MessageType: comment
Gerrit-Change-Id: I9f92178f642695e0e9ef901373a5e9f2878a78ce
Gerrit-PatchSet: 3
Gerrit-Project: Impala
Gerrit-Branch: cdh5-trunk
Gerrit-Owner: Henry Robinson <[email protected]>
Gerrit-Reviewer: Dan Hecht <[email protected]>
Gerrit-Reviewer: Henry Robinson <[email protected]>
Gerrit-Reviewer: Sailesh Mukil <[email protected]>
Gerrit-HasComments: Yes

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