/** Variant of {@link #trimFields(RelNode, BitSet, Set)} for {@link TableModificationRel}. */
public TrimResult trimFields(
TableModificationRel modifier, BitSet fieldsUsed, Set<RelDataTypeField> extraFields) {
// Ignore what consumer wants. We always project all columns.
Util.discard(fieldsUsed);
final RelDataType rowType = modifier.getRowType();
final int fieldCount = rowType.getFieldCount();
RelNode input = modifier.getChild();
// We want all fields from the child.
final int inputFieldCount = input.getRowType().getFieldCount();
BitSet inputFieldsUsed = Util.bitSetBetween(0, inputFieldCount);
// Create input with trimmed columns.
final Set<RelDataTypeField> inputExtraFields = Collections.emptySet();
TrimResult trimResult = trimChild(modifier, input, inputFieldsUsed, inputExtraFields);
RelNode newInput = trimResult.left;
final Mapping inputMapping = trimResult.right;
if (!inputMapping.isIdentity()) {
// We asked for all fields. Can't believe that the child decided
// to permute them!
throw Util.newInternal("Expected identity mapping, got " + inputMapping);
}
TableModificationRel newModifier = modifier;
if (newInput != input) {
newModifier = modifier.copy(modifier.getTraitSet(), Collections.singletonList(newInput));
}
assert newModifier.getClass() == modifier.getClass();
// Always project all fields.
Mapping mapping = Mappings.createIdentity(fieldCount);
return new TrimResult(newModifier, mapping);
}
/**
* Trims the fields of an input relational expression.
*
* @param rel Relational expression
* @param input Input relational expression, whose fields to trim
* @param fieldsUsed Bitmap of fields needed by the consumer
* @return New relational expression and its field mapping
*/
protected TrimResult trimChild(
RelNode rel, RelNode input, BitSet fieldsUsed, Set<RelDataTypeField> extraFields) {
Util.discard(rel);
if (input.getClass().getName().endsWith("MedMdrClassExtentRel")) {
// MedMdrJoinRule cannot handle Join of Project of
// MedMdrClassExtentRel, only naked MedMdrClassExtentRel.
// So, disable trimming.
fieldsUsed = Util.bitSetBetween(0, input.getRowType().getFieldCount());
}
return dispatchTrimFields(input, fieldsUsed, extraFields);
}
/**
* Records the fact that instances of <code>rel</code> are available via <code>bind</code> (which
* may be eager or lazy).
*/
private void bind(RelNode rel, Bind bind) {
tracer.log(Level.FINE, "Bind " + rel.toString() + " to " + bind);
JavaFrame frame = (JavaFrame) mapRel2Frame.get(rel);
frame.bind = bind;
boolean stupid = SaffronProperties.instance().stupid.get();
if (stupid) {
// trigger the declaration of the variable, even though it
// may not be used
Util.discard(bind.getVariable());
}
}
/**
* Creates a RelFieldTrimmer.
*
* @param validator Validator
*/
public RelFieldTrimmer(SqlValidator validator) {
Util.discard(validator); // may be useful one day
this.trimFieldsDispatcher =
ReflectUtil.createMethodDispatcher(
TrimResult.class, this, "trimFields", RelNode.class, BitSet.class, Set.class);
}
/**
* Visit method, per {@link org.eigenbase.util.ReflectiveVisitor}.
*
* <p>This method is invoked reflectively, so there may not be any apparent calls to it. The class
* (or derived classes) may contain overloads of this method with more specific types for the
* {@code rel} parameter.
*
* <p>Returns a pair: the relational expression created, and the mapping between the original
* fields and the fields of the newly created relational expression.
*
* @param rel Relational expression
* @param fieldsUsed Fields needed by the consumer
* @return relational expression and mapping
*/
public TrimResult trimFields(RelNode rel, BitSet fieldsUsed, Set<RelDataTypeField> extraFields) {
// We don't know how to trim this kind of relational expression, so give
// it back intact.
Util.discard(fieldsUsed);
return new TrimResult(rel, Mappings.createIdentity(rel.getRowType().getFieldCount()));
}