Java tutorial
/* * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package com.facebook.presto.tests.tpch; import com.facebook.presto.spi.ColumnHandle; import com.facebook.presto.spi.ConnectorResolvedIndex; import com.facebook.presto.spi.ConnectorSession; import com.facebook.presto.spi.ConnectorTableHandle; import com.facebook.presto.spi.predicate.NullableValue; import com.facebook.presto.spi.predicate.TupleDomain; import com.facebook.presto.tpch.TpchMetadata; import com.facebook.presto.tpch.TpchTableHandle; import com.google.common.collect.ImmutableList; import com.google.common.collect.ImmutableMap; import com.google.common.collect.ImmutableSet; import com.google.common.collect.Maps; import java.util.Map; import java.util.Optional; import java.util.Set; import java.util.stream.Collectors; import static com.facebook.presto.tests.tpch.TpchIndexProvider.handleToNames; import static com.google.common.base.Predicates.in; import static com.google.common.base.Predicates.not; import static java.util.Objects.requireNonNull; public class TpchIndexMetadata extends TpchMetadata { private final TpchIndexedData indexedData; public TpchIndexMetadata(String connectorId, TpchIndexedData indexedData) { super(connectorId); this.indexedData = requireNonNull(indexedData, "indexedData is null"); } @Override public Optional<ConnectorResolvedIndex> resolveIndex(ConnectorSession session, ConnectorTableHandle tableHandle, Set<ColumnHandle> indexableColumns, Set<ColumnHandle> outputColumns, TupleDomain<ColumnHandle> tupleDomain) { TpchTableHandle tpchTableHandle = (TpchTableHandle) tableHandle; // Keep the fixed values that don't overlap with the indexableColumns // Note: technically we could more efficiently utilize the overlapped columns, but this way is simpler for now Map<ColumnHandle, NullableValue> fixedValues = TupleDomain.extractFixedValues(tupleDomain) .orElse(ImmutableMap.of()).entrySet().stream() .filter(entry -> !indexableColumns.contains(entry.getKey())) .filter(entry -> !entry.getValue().isNull()) // strip nulls since meaningless in index join lookups .collect(Collectors.toMap(Map.Entry::getKey, Map.Entry::getValue)); // determine all columns available for index lookup Set<String> lookupColumnNames = ImmutableSet.<String>builder() .addAll(handleToNames(ImmutableList.copyOf(indexableColumns))) .addAll(handleToNames(ImmutableList.copyOf(fixedValues.keySet()))).build(); // do we have an index? if (!indexedData.getIndexedTable(tpchTableHandle.getTableName(), tpchTableHandle.getScaleFactor(), lookupColumnNames).isPresent()) { return Optional.empty(); } TupleDomain<ColumnHandle> filteredTupleDomain = tupleDomain; if (!tupleDomain.isNone()) { filteredTupleDomain = TupleDomain.withColumnDomains( Maps.filterKeys(tupleDomain.getDomains().get(), not(in(fixedValues.keySet())))); } TpchIndexHandle indexHandle = new TpchIndexHandle(tpchTableHandle.getTableName(), tpchTableHandle.getScaleFactor(), lookupColumnNames, TupleDomain.fromFixedValues(fixedValues)); return Optional.of(new ConnectorResolvedIndex(indexHandle, filteredTupleDomain)); } }