Thanks.
Basically, my requirements are:
1. pushdown projection
2. pushdown filters that are supported by the underlying data source, and
leave the unsupported one to Calcite.
I found that I should be able to achieve that with
ProjectableFilterableTable.
But, there is issue using this interface.
It throw exception with the projection column plus filter. For example, I
change one of the query of the ScannableTableTest to filter by column k.
This will not pushdown the filter, so Calcite will handle it.
java.sql.SQLException: error while executing SQL "select "i","k" from
"s"."beatles" where "k" = 1940": 2
at org.apache.calcite.avatica.Helper.createException(Helper.java:39)
at
org.apache.calcite.avatica.AvaticaStatement.executeQuery(AvaticaStatement.java:119)
at
org.apache.calcite.test.ScannableTableTest.testProjectableFilterable2WithProject(ScannableTableTest.java:193)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at
org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:47)
at
org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
at
org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:44)
at
org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:271)
at
org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:70)
at
org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:50)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229)
at org.junit.runners.ParentRunner.run(ParentRunner.java:309)
at
org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:50)
at
org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
at
org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467)
at
org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)
at
org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)
at
org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)
Caused by: java.lang.ArrayIndexOutOfBoundsException: 2
at
org.apache.calcite.interpreter.Interpreter$3.execute(Interpreter.java:193)
at org.apache.calcite.interpreter.Interpreter$2$1.get(Interpreter.java:177)
at
org.apache.calcite.interpreter.Interpreter$2.execute(Interpreter.java:130)
at org.apache.calcite.interpreter.FilterNode.run(FilterNode.java:42)
at org.apache.calcite.interpreter.Interpreter.start(Interpreter.java:97)
at
org.apache.calcite.interpreter.Interpreter.enumerator(Interpreter.java:64)
at
org.apache.calcite.linq4j.AbstractEnumerable.iterator(AbstractEnumerable.java:33)
at org.apache.calcite.avatica.MetaImpl.createCursor(MetaImpl.java:74)
at
org.apache.calcite.avatica.AvaticaResultSet.execute(AvaticaResultSet.java:182)
at
org.apache.calcite.jdbc.CalciteResultSet.execute(CalciteResultSet.java:62)
at org.apache.calcite.jdbc.CalciteResultSet.execute(CalciteResultSet.java:1)
at
org.apache.calcite.avatica.AvaticaConnection$1.execute(AvaticaConnection.java:461)
at
org.apache.calcite.jdbc.CalciteMetaImpl.prepareAndExecute(CalciteMetaImpl.java:475)
at
org.apache.calcite.avatica.AvaticaConnection.prepareAndExecuteInternal(AvaticaConnection.java:434)
at
org.apache.calcite.avatica.AvaticaStatement.executeQuery(AvaticaStatement.java:117)
... 24 more
>From the console:
Interpreter: rewrite
rel#75:EnumerableCalc.ENUMERABLE.[](input=rel#0:EnumerableTableScan.ENUMERABLE.[](table=[s,
beatles]),expr#0..2={inputs},expr#3=1940,expr#4==($t2,
$t3),$f0=$t0,$f1=$t2,$condition=$t4) to LogicalProject#78
Interpreter: rewrite LogicalProject#78 to LogicalFilter#80
The filter/condition is [=($2, 1940)]
I think the index of the condition/filter's column does not map to the
projected columns index. For this case the index of column 'K' after
projection should be 1 instead of 2.
Regards,
Chin Wei
On Fri, Jan 16, 2015 at 4:36 PM, Julian Hyde <[email protected]> wrote:
> IIRC, bind variables are accessible via DataContext.get("$0"), or some
> similar variable name. Take a look at the contents of the
> DataContextImpl.map field in a debugger. In generated java code,
> DataContext is available as a field called "root".
>
> Julian
>
>
> > On Jan 16, 2015, at 12:31 AM, Chin Wei Low <[email protected]> wrote:
> >
> > Hi,
> >
> > I am implementing a calcite adapter, and created a rule to pushdown
> filter.
> > When I execute a prepared statement, I can see the condition contains a
> > RexDynamicParam with value "?0" in the LogicalFilter.
> > How can I get the value of the bind variable, so I can push it down to
> the
> > underlying data source.
> >
> > Regards,
> > Chin Wei
>
>
