Julian Hyde updated CALCITE-1429:
    Summary: Druid adapter must send "fromNext" when requesting rows from Druid 
 (was: Error of fetching data in select query for Druid)

> Druid adapter must send "fromNext" when requesting rows from Druid
> ------------------------------------------------------------------
>                 Key: CALCITE-1429
>                 URL: https://issues.apache.org/jira/browse/CALCITE-1429
>             Project: Calcite
>          Issue Type: Bug
>          Components: druid
>            Reporter: Jiarong Wei
>            Assignee: Julian Hyde
> As mentioned in [Druid 
> documentation|http://druid.io/docs/],
> {quote}
> Note that in the second query, an offset is specified and that it is 1 
> greater than the largest offset found in the initial results. To return the 
> next "page", this offset must be incremented by 1 (should be decremented by 1 
> for descending query), with each new query, but with option {{fromNext}} 
> enabled, this operation is not needed. When an empty results set is received, 
> the very last page has been returned.
> {quote}
> I think Druid adapter 
> [presumes|https://github.com/apache/calcite/blob/master/druid/src/main/java/org/apache/calcite/adapter/druid/DruidQuery.java#L935]
>  this feature is turned on but it's not set in 
> [code|https://github.com/apache/calcite/blob/master/druid/src/main/java/org/apache/calcite/adapter/druid/DruidQuery.java#L627].
> Also, {{previousOffset}} may not be reasonable, see 
> [DruidQuery|https://github.com/apache/calcite/blob/master/druid/src/main/java/org/apache/calcite/adapter/druid/DruidQuery.java#L940].
>  I think whether we have already fetched all data is decided by the next 
> request. If we don't have any data returned on next request, that means 
> fetching is done.

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