[ https://issues.apache.org/jira/browse/PIG-1635?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12914150#action_12914150 ]
Yan Zhou commented on PIG-1635: ------------------------------- All test-core tests also run clean. > Logical simplifier does not simplify away constants under AND and OR; after > simplificaion the ordering of operands of AND and OR may get changed > ------------------------------------------------------------------------------------------------------------------------------------------------ > > Key: PIG-1635 > URL: https://issues.apache.org/jira/browse/PIG-1635 > Project: Pig > Issue Type: Bug > Components: impl > Affects Versions: 0.8.0 > Reporter: Yan Zhou > Assignee: Yan Zhou > Priority: Minor > Fix For: 0.8.0 > > Attachments: PIG-1635.patch > > > b = FILTER a by (( f1 > 1) AND (1 == 1)) > or > b = FILTER a by ((f1 > 1) OR ( 1==0)) > should be simplified to > b = FILTER a by f1 > 1; > Regarding ordering change, an example is that > b = filter a by ((f1 is not null) AND (f2 is not null)); > Even without possible simplification, the expression is changed to > b = filter a by ((f2 is not null) AND (f1 is not null)); > Even though the ordering change in this case, and probably in most other > cases, does not create any difference, but for two reasons some users might > care about the ordering: if stateful UDFs are used as operands of AND or OR; > and if the ordering is intended by the application designer to maximize the > chances to shortcut the composite boolean evaluation. -- This message is automatically generated by JIRA. - You can reply to this email to add a comment to the issue online.