Would it be acceptable to make this a doc Jira? Add a note in the documentation ( https://www.cloudera.com/documentation/enterprise/latest/topics/impala_shell_options.html) to escape the $ if this error is received and the incorrect declaration needs to stay for whatever reason.
On Tue, Jun 26, 2018 at 10:50 AM Fredy Wijaya <[email protected]> wrote: > I think the confusion is why ${var_name} (without the VAR prefix) is > considered as an error, especially if we only support ${VAR:var_name}. > [localhost:21000] default> -- ${hello} > select 1; > Error: Unknown substitution syntax (HELLO). Use ${VAR:var_name} > > The workaround is rather trivial that is to escape it. > [localhost:21000] default> -- \${hello} > select 1; > Query: -- \${hello} > select 1 > > I also agree that unset variables should still be treated as an error > regardless where they're located whether in comments or non-comments. > Escaping should be use to ignore variable substitutions. > > On Tue, Jun 26, 2018 at 7:36 AM Csaba Ringhofer <[email protected]> > wrote: > >> >fixed in a manner that would still allow query hints >> I would vote for this. >> A possible solution could be to replace variables in comments only if the >> variable is set (so no longer treat it as an error). Referencing unset >> variables in non-comment code should be still treated as an error. >> This would not break any existing queries, and the only problematic side >> effect would be that "mistyped variables that should be hints" would be >> harder to detect, but that should be a very rare issue. >> I checked Hive shell and replaces it variables only if they are set, even >> in non-comment code, but I think that it is better to treat this as en >> error. >> >> > fixed for all comments in variables >> I would not go this way, as it could break some existing use cases. This >> should be very rare, but as the original issue seems like a minor nuisance >> to me, I think that it would be better to leave it as it is than to >> introduce a breaking change. >> >> On Mon, Jun 25, 2018 at 9:01 PM, Tim Armstrong <[email protected]> >> wrote: >> >>> What is the original motivation for the JIRA? Is there a use case where >>> the current behaviour is a problem? >>> >>> On Mon, Jun 25, 2018 at 11:38 AM, Adam Holley <[email protected]> >>> wrote: >>> >>>> Hello all, >>>> >>>> There is a Jira (https://issues.apache.org/jira/browse/IMPALA-3956) to >>>> change Impala so that variables within comments are not replaced. However, >>>> since Impala can use query hints in comments, fixing this as stated removes >>>> the ability to use hints through variables. Does the community think this >>>> should be fixed for all comments in variables, left alone, fixed in a >>>> manner that would still allow query hints, or some other alternative? >>>> >>>> Thanks. >>>> >>>> >>>> -- >>>> *Adam Holley* | Engineering >>>> t. (512) 484-4060 >>>> cloudera.com <https://www.cloudera.com> >>>> >>>> [image: Cloudera] <https://www.cloudera.com/> >>>> >>>> [image: Cloudera on Twitter] <https://twitter.com/cloudera> [image: >>>> Cloudera on Facebook] <https://www.facebook.com/cloudera> [image: >>>> Cloudera on LinkedIn] <https://www.linkedin.com/company/cloudera> >>>> ------------------------------ >>>> >>> >>> >> -- *Adam Holley* | Engineering t. (512) 484- <javascript:void(0);>4060 cloudera.com <https://www.cloudera.com> [image: Cloudera] <https://www.cloudera.com/> [image: Cloudera on Twitter] <https://twitter.com/cloudera> [image: Cloudera on Facebook] <https://www.facebook.com/cloudera> [image: Cloudera on LinkedIn] <https://www.linkedin.com/company/cloudera> ------------------------------
