Tim Armstrong has posted comments on this change. ( http://gerrit.cloudera.org:8080/11517 )
Change subject: [WIP] IMPALA-6932: Speed up scans for sequence datasets with many files ...................................................................... Patch Set 2: (4 comments) http://gerrit.cloudera.org:8080/#/c/11517/2/be/src/exec/hdfs-scan-node-base.h File be/src/exec/hdfs-scan-node-base.h: http://gerrit.cloudera.org:8080/#/c/11517/2/be/src/exec/hdfs-scan-node-base.h@262 PS2, Line 262: EnqueueLocation enqueue_location = EnqueueLocation::TAIL) WARN_UNUSED_RESULT; I think this is a reasonable place to use a default argument value but I'm generally a little sceptical of them, versus forcing callers to be explicit about what mode they are using. For systems code I find it's useful to force callers to think about what mode they want and have it explicit at the callsite, even though it is more verbose. I've seen a number of cases where a default argument value obscured a bug that might otherwise have been obvious. Anyway, this seems OK since the default is reasonable, just wanted to document my thought process about this. http://gerrit.cloudera.org:8080/#/c/11517/2/be/src/exec/hdfs-scan-node.h File be/src/exec/hdfs-scan-node.h: http://gerrit.cloudera.org:8080/#/c/11517/2/be/src/exec/hdfs-scan-node.h@90 PS2, Line 90: int num_files_queued, EnqueueLocation enqueue_location = weird line wrapping. Ok to leave if clang-format did this. http://gerrit.cloudera.org:8080/#/c/11517/2/be/src/runtime/io/request-context.h File be/src/runtime/io/request-context.h: http://gerrit.cloudera.org:8080/#/c/11517/2/be/src/runtime/io/request-context.h@28 PS2, Line 28: extra space http://gerrit.cloudera.org:8080/#/c/11517/2/be/src/runtime/io/request-context.cc File be/src/runtime/io/request-context.cc: http://gerrit.cloudera.org:8080/#/c/11517/2/be/src/runtime/io/request-context.cc@358 PS2, Line 358: disk_state->unstarted_scan_ranges()->PushFront(scan_range); Add a DCHECK_ENUM_EQ to assert that it's UPON_GETNEXT_HEAD so that the assumed invariant is enforced. -- To view, visit http://gerrit.cloudera.org:8080/11517 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-MessageType: comment Gerrit-Change-Id: I211e2511ea3bb5edea29f1bd63e6b1fa4c4b1965 Gerrit-Change-Number: 11517 Gerrit-PatchSet: 2 Gerrit-Owner: Pooja Nilangekar <[email protected]> Gerrit-Reviewer: Bikramjeet Vig <[email protected]> Gerrit-Reviewer: Impala Public Jenkins <[email protected]> Gerrit-Reviewer: Pooja Nilangekar <[email protected]> Gerrit-Reviewer: Tim Armstrong <[email protected]> Gerrit-Comment-Date: Mon, 22 Oct 2018 15:34:09 +0000 Gerrit-HasComments: Yes
