[jira] [Created] (OPTIQ-436) Simpler SPI to query Table

[Julian Hyde (JIRA)]

Julian Hyde created OPTIQ-436:
---------------------------------

             Summary: Simpler SPI to query Table
                 Key: OPTIQ-436
                 URL: https://issues.apache.org/jira/browse/OPTIQ-436
             Project: Optiq
          Issue Type: Bug
            Reporter: Julian Hyde
            Assignee: Julian Hyde


Currently, the easiest way for a Table to return results is to implement 
TranslatableTable, and in the toRel method return a RelNode. That RelNode is 
typically a sub-class of TableAccessRelBase and implements itself by generating 
Java code, which must be compiled an executed.

We propose an interfaces so that a Table can return results directly.

{code}
import net.hydromatic.avatica.Cursor;
import org.eigenbase.util.Pair;
import net.hydromatic.optiq.Table;
import org.eigenbase.rex.RexNode;
import org.eigenbase.reltype.RelDataTypeField;

interface CursorableTable extends Table {
  /** Returns a cursor over the rows in this Table. */
  Cursor scan();
}

interface ProjectableCursorableTable extends Table {
  /** Given a list of filters and a list of fields to project, returns a
   * cursor over the rows in this Table and a list of filters that it
   * could not implement.
   *
   * <p>The cursor must implement the projects and any filters not
   * in the list. */
  Pair<Cursor, List<RexNode>> projectFilterScan(List<RexNode> filters, 
List<RelDataTypeField> projects);
}
{code}




--
This message was sent by Atlassian JIRA
(v6.3.4#6332)