[ https://issues.apache.org/jira/browse/MAHOUT-1800?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15184385#comment-15184385 ]
ASF GitHub Bot commented on MAHOUT-1800: ---------------------------------------- Github user asfgit closed the pull request at: https://github.com/apache/mahout/pull/183 > Pare down Casstag overuse > ------------------------- > > Key: MAHOUT-1800 > URL: https://issues.apache.org/jira/browse/MAHOUT-1800 > Project: Mahout > Issue Type: Improvement > Affects Versions: 0.11.1 > Reporter: Andrew Palumbo > Fix For: 0.11.2 > > > currently, almost every operator requires implicit parameter for the classtag > context bound of drm rowset key type, even for things like drmA + drmB. > in reality though DAG can already infer that similarly to e.g. it infers > product geometry because classtags are already embedded in the logical plan. > for example, {{classtag(drmA+drmB) == classtag(drmA) == classtag(drmB)}}. > Not only does the DAG already contain this information, but also it opens > doors to a loss of inference, since the optimizer doesn't verify that the new > context bound is actually valid by retracing the inference. So any operation > may introduce an invalid row key type, and as a consequence, invalid > optimization information, without any further checks. -- This message was sent by Atlassian JIRA (v6.3.4#6332)