Marcel Kornacker has posted comments on this change. Change subject: IMPALA-4787: Optimize APPX_MEDIAN() memory usage ......................................................................
Patch Set 14: (10 comments) http://gerrit.cloudera.org:8080/#/c/6025/14/be/src/exprs/aggregate-functions-ir.cc File be/src/exprs/aggregate-functions-ir.cc: Line 908: const static int INIT_CAPACITY = 16; move those constants into the classes that use them Line 981: // stored in a dynamically sized array. See the ".h" file for more details. briefly describe memory mgmt, in particular the switch to the inlined representation. i didn't get the "see .h for more details part", is there anything relevant to this in there? Line 1040: // contains. Frees the memory of the current object. Requires a call Deserialize() call fix grammar point out that the array must not be inlined Line 1062: DCHECK(!sample_array_inline_); dcheck this at the top, makes it easier to pick up on it. Line 1085: // reservoir sampling algorithm. point out all side effects (increase of capacity; when that fails) Line 1100: // First, fill up the dst samples if they don't already exist. The samples are now separate logically separate blocks with blank lines Line 1124: if (num_samples_ == 0) { single line Line 1138: void Free(FunctionContext* ctx) { call this Delete, because that's what it basically implements (free() only frees the memory directly allocated for that pointer) Line 1151: // resize occurs, this needs to be updated. i'm assuming this is the size of the array. comment. Line 1169: // Increases the size of the samples array to a rounded up to a power of two "array to new_capacity, rounded up to a power of two." -- To view, visit http://gerrit.cloudera.org:8080/6025 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-MessageType: comment Gerrit-Change-Id: I99adaad574d4fb0a3cf38c6cbad8b2a23df12968 Gerrit-PatchSet: 14 Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-Owner: Taras Bobrovytsky <tbobrovyt...@cloudera.com> Gerrit-Reviewer: Alex Behm <alex.b...@cloudera.com> Gerrit-Reviewer: Jim Apple <jbapple-imp...@apache.org> Gerrit-Reviewer: Marcel Kornacker <mar...@cloudera.com> Gerrit-Reviewer: Matthew Jacobs <m...@cloudera.com> Gerrit-Reviewer: Mostafa Mokhtar <mmokh...@cloudera.com> Gerrit-Reviewer: Taras Bobrovytsky <tbobrovyt...@cloudera.com> Gerrit-HasComments: Yes
