Taras Bobrovytsky has posted comments on this change. Change subject: IMPALA-4939, IMPALA-4939: Decimal V2 multiplication ......................................................................
Patch Set 3: (4 comments) http://gerrit.cloudera.org:8080/#/c/7438/1/be/src/runtime/decimal-value.inline.h File be/src/runtime/decimal-value.inline.h: Line 301: // doubling such a value would overflow in two's complement. However, we > A while loop will perform terribly, but there are intrinsics that can be us Added a TODO. http://gerrit.cloudera.org:8080/#/c/7438/1/be/src/util/bit-util.h File be/src/util/bit-util.h: Line 65: return value < 0 ? -1 : 1; > I think we want to think carefully about using the Sign function with int25 I included the benchmark result in the commit message. http://gerrit.cloudera.org:8080/#/c/7438/1/be/src/util/decimal-util.h File be/src/util/decimal-util.h: Line 336 > Really? That's crazy. I removed this function so that the function on line 58 would get called. http://gerrit.cloudera.org:8080/#/c/7438/1/fe/src/main/java/org/apache/impala/analysis/TypesUtil.java File fe/src/main/java/org/apache/impala/analysis/TypesUtil.java: Line 260: resultPrecision = p1 + p2 + 1; > I think the 0.999 * 0.999 case is a fluke - we are sacrificing precision fo This is more of a product question. I'll ask Greg about this later. -- To view, visit http://gerrit.cloudera.org:8080/7438 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-MessageType: comment Gerrit-Change-Id: I37ad6232d7953bd75c18dc86e665b2b501a1ebe1 Gerrit-PatchSet: 3 Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-Owner: Taras Bobrovytsky <tbobrovyt...@cloudera.com> Gerrit-Reviewer: Dan Hecht <dhe...@cloudera.com> Gerrit-Reviewer: Michael Ho <k...@cloudera.com> Gerrit-Reviewer: Taras Bobrovytsky <tbobrovyt...@cloudera.com> Gerrit-Reviewer: Tim Armstrong <tarmstr...@cloudera.com> Gerrit-Reviewer: Zach Amsden <zams...@cloudera.com> Gerrit-HasComments: Yes
