Michael Ho has posted comments on this change. Change subject: IMPALA-3629: Codegen TransferScratchTuples() in hdfs-parquet-scanner ......................................................................
Patch Set 3: (2 comments) http://gerrit.cloudera.org:8080/#/c/3774/3/be/src/exec/hdfs-parquet-scanner-ir.cc File be/src/exec/hdfs-parquet-scanner-ir.cc: PS3, Line 44: if (tuple_size == 0) { > Given that if (tuple_size == 0) { ...} is handling an entire scratch patch On the other hand, tuple_size is known at compilation time so either this loop or the code after this loop will be eliminated so the codegen time may not be as bad as I initially thought. If we ever go through this loop multiple times, the branch may be quite predictable. Did you see measurable performance difference when say scanning large files by removing this if-check ? http://gerrit.cloudera.org:8080/#/c/3774/3/be/src/exec/hdfs-parquet-scanner.cc File be/src/exec/hdfs-parquet-scanner.cc: PS3, Line 520: num_row_to_commit = codegend_transfer_scratch_tuples_fn_(this, tuple_size, has_filters); long line. -- To view, visit http://gerrit.cloudera.org:8080/3774 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-MessageType: comment Gerrit-Change-Id: Ic327e437c7cd2b3f92cdb11c1e907bfee2d44ee8 Gerrit-PatchSet: 3 Gerrit-Project: Impala Gerrit-Branch: cdh5-trunk Gerrit-Owner: Thomas Tauber-Marshall <[email protected]> Gerrit-Reviewer: Michael Ho <[email protected]> Gerrit-Reviewer: Thomas Tauber-Marshall <[email protected]> Gerrit-Reviewer: Tim Armstrong <[email protected]> Gerrit-HasComments: Yes
