Re: monotonic column not working

[Julian Hyde <jh...@apache.org>]

Monotonic columns aren’t fully implemented yet. I use them as a concept in the streaming SQL examples, and they will be central when we’ve fully implemented streaming SQL (although people might also use related concepts like watermarks and partially-sorted columns).

We have some support for deducing monotonic expressions: if, say, x and y are ascending, then we can deduce that so is x + y.

But we can’t yet declare columns to be monotonic. SqlValidatorTest.testStreamGroupBy relies on MockCatalogReader.MockTable’s dummy implementation of getMonotonicity(String columnName).

This is very much a work in progress. (Contributions welcome, of course!)

Julian


> On Oct 31, 2016, at 10:30 AM, Nuwan Abeysiriwardana <nu...@gmail.com> wrote:
> 
> Hi All,
> 
> i have  create a table which handle stream of java hashmap pair with the
> rowTime column. abstract table getRowType implementation given below.
> 
> @Override
>    public RelDataType getRowType(RelDataTypeFactory typeFactory) {
>            return typeFactory.builder().add("_MAP",
>        typeFactory.createMapType(
>            typeFactory.createSqlType(SqlTypeName.VARCHAR),
>            typeFactory.createTypeWithNullability(
>                typeFactory.createSqlType(SqlTypeName.ANY),
> true))).add("rowTime",typeFactory.createSqlType(SqlTypeName.TIMESTAMP)).build();
>    }
> 
> idea is to use order by with floor(rowTime TO HOUR) .sample query as
> follows.
> 
> select stream _MAP['name'],rowTime from event where cast(_MAP['age'] as INT
> )  >= 10 order by floor(event.rowTime TO HOUR)
> 
> it giving me error saying  : 'Streaming ORDER BY must start with monotonic
> expression'
> 
> i can't find any special handling in the sample csv stream implementation
> as well.
> 
> following query works fine.
>   select stream _MAP['name'],rowTime from event
> 
> so that means rowTime identified properly as timestamp.
> please help.
> 
> calcite version :
>  <dependency>
>                <groupId>org.apache.calcite</groupId>
>                <artifactId>calcite-core</artifactId>
>                <version>1.10.0</version>
>            </dependency>
> 
> thanks
> nuwan