Dan Burkert has posted comments on this change. Change subject: Add ColumnPredicate class ......................................................................
Patch Set 2: (1 comment) http://gerrit.cloudera.org:8080/#/c/2137/2/src/kudu/common/column_predicate.h File src/kudu/common/column_predicate.h: Line 169: // Compares predicates according to selectivity. > I think the standard database terminology is that 'selectivity' is the % of I don't think the blog post is saying that: "High selectivity implies high uniqueness, or a low number of matching values." "Selectivity for a filter predicate against a base table can be calculated as "[# rows that pass the predicate]/[# rows in the table]". If the predicate passes all rows in the table, its selectivity is 1.0. If it disqualifies all rows, its selectivity is 0. (This can be confusing. Note that 0.000001 reflects a high selectivity even though the number is small, while 1.0 is low selectivity even though the number is higher.)" -- To view, visit http://gerrit.cloudera.org:8080/2137 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-MessageType: comment Gerrit-Change-Id: I72cac35d7a168f96c2ee52afd284489e99755e3f Gerrit-PatchSet: 2 Gerrit-Project: kudu Gerrit-Branch: master Gerrit-Owner: Dan Burkert <[email protected]> Gerrit-Reviewer: Adar Dembo <[email protected]> Gerrit-Reviewer: Dan Burkert <[email protected]> Gerrit-Reviewer: David Ribeiro Alves <[email protected]> Gerrit-Reviewer: Jean-Daniel Cryans Gerrit-Reviewer: Kudu Jenkins Gerrit-Reviewer: Todd Lipcon <[email protected]> Gerrit-HasComments: Yes
