本文整理汇总了Java中org.apache.calcite.tools.RelBuilder.convert方法的典型用法代码示例。如果您正苦于以下问题：Java RelBuilder.convert方法的具体用法？Java RelBuilder.convert怎么用？Java RelBuilder.convert使用的例子？那么恭喜您, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在类org.apache.calcite.tools.RelBuilder的用法示例。
在下文中一共展示了RelBuilder.convert方法的1个代码示例，这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞，您的评价将有助于系统推荐出更棒的Java代码示例。
示例1: onMatch
import org.apache.calcite.tools.RelBuilder; //导入方法依赖的package包/类
@Override public void onMatch(RelOptRuleCall call) {
final Union union = call.rel(0);
final int count = union.getRowType().getFieldCount();
if (count == 1) {
// No room for optimization since we cannot create an empty Project
// operator. If we created a Project with one column, this rule would
// cycle.
return;
}
final RexBuilder rexBuilder = union.getCluster().getRexBuilder();
final RelMetadataQuery mq = call.getMetadataQuery();
final RelOptPredicateList predicates = mq.getPulledUpPredicates(union);
if (predicates == null) {
return;
}
final Map<Integer, RexNode> constants = new HashMap<>();
for (Map.Entry<RexNode, RexNode> e : predicates.constantMap.entrySet()) {
if (e.getKey() instanceof RexInputRef) {
constants.put(((RexInputRef) e.getKey()).getIndex(), e.getValue());
}
}
// None of the expressions are constant. Nothing to do.
if (constants.isEmpty()) {
return;
}
// Create expressions for Project operators before and after the Union
List<RelDataTypeField> fields = union.getRowType().getFieldList();
List<RexNode> topChildExprs = new ArrayList<>();
List<String> topChildExprsFields = new ArrayList<>();
List<RexNode> refs = new ArrayList<>();
ImmutableBitSet.Builder refsIndexBuilder = ImmutableBitSet.builder();
for (RelDataTypeField field : fields) {
final RexNode constant = constants.get(field.getIndex());
if (constant != null) {
topChildExprs.add(constant);
topChildExprsFields.add(field.getName());
} else {
final RexNode expr = rexBuilder.makeInputRef(union, field.getIndex());
topChildExprs.add(expr);
topChildExprsFields.add(field.getName());
refs.add(expr);
refsIndexBuilder.set(field.getIndex());
}
}
ImmutableBitSet refsIndex = refsIndexBuilder.build();
// Update top Project positions
final Mappings.TargetMapping mapping =
RelOptUtil.permutation(refs, union.getInput(0).getRowType()).inverse();
topChildExprs = ImmutableList.copyOf(RexUtil.apply(mapping, topChildExprs));
// Create new Project-Union-Project sequences
final RelBuilder relBuilder = call.builder();
for (RelNode input : union.getInputs()) {
List<Pair<RexNode, String>> newChildExprs = new ArrayList<>();
for (int j : refsIndex) {
newChildExprs.add(
Pair.<RexNode, String>of(rexBuilder.makeInputRef(input, j),
input.getRowType().getFieldList().get(j).getName()));
}
if (newChildExprs.isEmpty()) {
// At least a single item in project is required.
newChildExprs.add(
Pair.of(topChildExprs.get(0), topChildExprsFields.get(0)));
}
// Add the input with project on top
relBuilder.push(input);
relBuilder.project(Pair.left(newChildExprs), Pair.right(newChildExprs));
}
relBuilder.union(union.all, union.getInputs().size());
// Create top Project fixing nullability of fields
relBuilder.project(topChildExprs, topChildExprsFields);
relBuilder.convert(union.getRowType(), false);
call.transformTo(relBuilder.build());
}