Ok I will log a JIRA case and try to add a test. Won't be able to get to it till tonight when I'm back on my laptop.
Kevin Risden On Mon, Feb 20, 2017 at 1:58 PM, Julian Hyde <[email protected]> wrote: > I do think it’s worth considering. Can you log a JIRA case please? > > Also, if you add a test — probably a few extra lines in RexProgramTest > will suffice — I will accept your PR. I think it will be efficient enough. > > Julian > > > > On Feb 19, 2017, at 7:14 PM, Kevin Risden <[email protected]> > wrote: > > > > Thanks Julian. I looked in the existing rules but didn't come across the > > ReduceExpressionsRule.FILTER_INSTANCE. Adding that rule to the planner > > seems to do the same thing that I was trying to do in simplify. I don't > > think there is any reason to change simplify. It was just the first way > to > > found to try to work around the issue I was facing. > > > > Would you still want a JIRA case logged since that would result in > multiple > > ways of doing the same thing? > > > > Kevin Risden > > > > On Sun, Feb 19, 2017 at 8:13 PM, Julian Hyde <[email protected] <mailto: > [email protected]>> wrote: > > > >> We have support for this in planner rules -- I’m pretty sure that > >> ReduceExpressionsRule.FILTER_INSTANCE will convert ‘where 1 = 0’ to > >> ‘where false’, then PruneEmptyRules.FILTER_INSTANCE will make the > Filter > >> disappear altogether — but arguably it could happen in RexUtil.simplify > >> also. > >> > >> The purpose of RexUtil.simplify is to simplify (only) patterns that are > >> commonly occurring, easy to recognize, and will produce a quick win in > >> terms of the size of the RelNode/RexNode tree. I don’t know yet whether > >> this passes that threshold. Can you log a JIRA case for this and we can > >> discuss further? > >> > >> By the way, https://issues.apache.org/jira/browse/CALCITE-1638 < > >> https://issues.apache.org/jira/browse/CALCITE-1638 < > https://issues.apache.org/jira/browse/CALCITE-1638>> is related. It > >> changed the result of a test that was doing ‘where 1 = 1’. > >> > >> Julian > >> > >> > >> > >> > >>> On Feb 19, 2017, at 2:03 PM, Kevin Risden <[email protected]> > >> wrote: > >>> > >>> While working on Solr and Calcite integration, I found that there is a > >> case > >>> where some tools issue a sql query like "where 1 = 0" just to get > >> metadata > >>> information back. Spark SQL is one of the ones that does this. > >>> > >>> Calcite doesn't seem to optimize away the literal comparison literal > case > >>> with RexUtil.simplify. In my understanding any literal comparison > literal > >>> results in a simple TRUE/FALSE result. > >>> > >>> I'm not sure this is valid in the general case, but I put together a > >> simple > >>> example of doing this on the RexUtil simplifyCall. > >>> > >>> https://github.com/apache/calcite/pull/376 > >>> > >>> I would love to hear any feedback related to this. I need to run > through > >>> the full Calcite test suite, but wondering if this is even viable. > >>> > >>> Thanks! > >>> > >>> Kevin Risden > >
