[jira] [Commented] (CALCITE-1424) Invalid column type in DruidConnectionImpl

["Julian Hyde (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/CALCITE-1424?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15560787#comment-15560787 ] 

Julian Hyde commented on CALCITE-1424:
--------------------------------------

I think I was misled because Druid has aggregate functions such as {{doubleSum}}.

For the record:
* In SQL, the types {{DOUBLE}} and {{FLOAT}} are both 64-bit floating point, {{REAL}} is 32-bit floating point, and {{BIGINT}} is 64-bit signed integer.
* In Java, {{double}} is 64 bit floating point, {{float}} is 32 bit floating point, {{long}} is 64 bit signed integer.

Can you please clarify whether Druid's {{FLOAT}} type is 32-bit or 64-bit? I presume that Druid's {{LONG}} is 64-bit signed integer.

Once we have clarified the content of Druid's types (how many bits, etc.), we should make sure that Calcite's Druid adapter surfaces columns with the appropriate SQL types for that content. 

> Invalid column type in DruidConnectionImpl
> ------------------------------------------
>
>                 Key: CALCITE-1424
>                 URL: https://issues.apache.org/jira/browse/CALCITE-1424
>             Project: Calcite
>          Issue Type: Bug
>          Components: druid
>            Reporter: Jiarong Wei
>            Assignee: Julian Hyde
>
> Currently the supported column types in Druid adapter are: {{LONG}}, {{DOUBLE}}, {{STRING}} and {{hyperUnique}}
> There's no clue to show Druid has {{DOUBLE}} as its column type. But instead it should be {{FLOAT}} as mentioned in [Druid Documentation|http://druid.io/docs/latest/querying/segmentmetadataquery.html]:
> bq. Dimension columns will have type STRING. Metric columns will have type FLOAT or LONG or name of the underlying complex type such as hyperUnique in case of COMPLEX metric. Timestamp column will have type LONG.
> Fangjin Yang didn't mentioned it in related posts either. See [1|https://groups.google.com/forum/#!msg/druid-development/U_24K3FLveM/kE-T1NluqHsJ] and [2|https://groups.google.com/forum/#!msg/druid-development/cVTJrrxq7kI/MhM3FF3g0x8J]



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