@Override
public Prel visitProject(ProjectPrel project, Object unused) throws RelConversionException {
// Apply the rule to the child
RelNode originalInput = ((Prel) project.getInput(0)).accept(this, null);
project = (ProjectPrel) project.copy(project.getTraitSet(), Lists.newArrayList(originalInput));
List<RexNode> exprList = new ArrayList<>();
List<RelDataTypeField> relDataTypes = new ArrayList();
List<RelDataTypeField> origRelDataTypes = new ArrayList();
int i = 0;
final int lastColumnReferenced = PrelUtil.getLastUsedColumnReference(project.getProjects());
if (lastColumnReferenced == -1) {
return project;
}
final int lastRexInput = lastColumnReferenced + 1;
RexVisitorComplexExprSplitter exprSplitter =
new RexVisitorComplexExprSplitter(factory, funcReg, lastRexInput);
for (RexNode rex : project.getChildExps()) {
origRelDataTypes.add(project.getRowType().getFieldList().get(i));
i++;
exprList.add(rex.accept(exprSplitter));
}
List<RexNode> complexExprs = exprSplitter.getComplexExprs();
if (complexExprs.size() == 1 && findTopComplexFunc(project.getChildExps()).size() == 1) {
return project;
}
ProjectPrel childProject;
List<RexNode> allExprs = new ArrayList();
int exprIndex = 0;
List<String> fieldNames = originalInput.getRowType().getFieldNames();
for (int index = 0; index < lastRexInput; index++) {
RexBuilder builder = new RexBuilder(factory);
allExprs.add(
builder.makeInputRef(new RelDataTypeDrillImpl(new RelDataTypeHolder(), factory), index));
if (fieldNames.get(index).contains(StarColumnHelper.STAR_COLUMN)) {
relDataTypes.add(
new RelDataTypeFieldImpl(
fieldNames.get(index), allExprs.size(), factory.createSqlType(SqlTypeName.ANY)));
} else {
relDataTypes.add(
new RelDataTypeFieldImpl(
"EXPR$" + exprIndex, allExprs.size(), factory.createSqlType(SqlTypeName.ANY)));
exprIndex++;
}
}
RexNode currRexNode;
int index = lastRexInput - 1;
// if the projection expressions contained complex outputs, split them into their own individual
// projects
if (complexExprs.size() > 0) {
while (complexExprs.size() > 0) {
if (index >= lastRexInput) {
allExprs.remove(allExprs.size() - 1);
RexBuilder builder = new RexBuilder(factory);
allExprs.add(
builder.makeInputRef(
new RelDataTypeDrillImpl(new RelDataTypeHolder(), factory), index));
}
index++;
exprIndex++;
currRexNode = complexExprs.remove(0);
allExprs.add(currRexNode);
relDataTypes.add(
new RelDataTypeFieldImpl(
"EXPR$" + exprIndex, allExprs.size(), factory.createSqlType(SqlTypeName.ANY)));
childProject =
new ProjectPrel(
project.getCluster(),
project.getTraitSet(),
originalInput,
ImmutableList.copyOf(allExprs),
new RelRecordType(relDataTypes));
originalInput = childProject;
}
// copied from above, find a better way to do this
allExprs.remove(allExprs.size() - 1);
RexBuilder builder = new RexBuilder(factory);
allExprs.add(
builder.makeInputRef(new RelDataTypeDrillImpl(new RelDataTypeHolder(), factory), index));
relDataTypes.add(
new RelDataTypeFieldImpl(
"EXPR$" + index, allExprs.size(), factory.createSqlType(SqlTypeName.ANY)));
}
return (Prel)
project.copy(
project.getTraitSet(), originalInput, exprList, new RelRecordType(origRelDataTypes));
}
