private List<CassandraPartition> getCassandraPartitions( CassandraTable table, TupleDomain<ColumnHandle> tupleDomain) { if (tupleDomain.isNone()) { return ImmutableList.of(); } Set<List<Comparable<?>>> partitionKeysSet = getPartitionKeysSet(table, tupleDomain); // empty filter means, all partitions if (partitionKeysSet.isEmpty()) { return schemaProvider.getAllPartitions(table); } ImmutableList.Builder<ListenableFuture<List<CassandraPartition>>> getPartitionResults = ImmutableList.builder(); for (List<Comparable<?>> partitionKeys : partitionKeysSet) { getPartitionResults.add( executor.submit(() -> schemaProvider.getPartitions(table, partitionKeys))); } ImmutableList.Builder<CassandraPartition> partitions = ImmutableList.builder(); for (ListenableFuture<List<CassandraPartition>> result : getPartitionResults.build()) { try { partitions.addAll(result.get()); } catch (InterruptedException e) { Thread.currentThread().interrupt(); throw Throwables.propagate(e); } catch (ExecutionException e) { throw new PrestoException(EXTERNAL, "Error fetching cassandra partitions", e); } } return partitions.build(); }
@Override public ConnectorSplitSource getPartitionSplits( ConnectorSession session, ConnectorTableHandle tableHandle, List<ConnectorPartition> partitions) { checkNotNull(tableHandle, "tableHandle is null"); CassandraTableHandle cassandraTableHandle = checkType(tableHandle, CassandraTableHandle.class, "tableHandle"); checkNotNull(partitions, "partitions is null"); if (partitions.isEmpty()) { return new FixedSplitSource(connectorId, ImmutableList.<ConnectorSplit>of()); } // if this is an unpartitioned table, split into equal ranges if (partitions.size() == 1) { ConnectorPartition partition = partitions.get(0); CassandraPartition cassandraPartition = checkType(partition, CassandraPartition.class, "partition"); if (cassandraPartition.isUnpartitioned() || cassandraPartition.isIndexedColumnPredicatePushdown()) { CassandraTable table = schemaProvider.getTable(cassandraTableHandle); List<ConnectorSplit> splits = getSplitsByTokenRange(table, cassandraPartition.getPartitionId()); return new FixedSplitSource(connectorId, splits); } } return new FixedSplitSource( connectorId, getSplitsForPartitions(cassandraTableHandle, partitions)); }
@Override public ConnectorPartitionResult getPartitions( ConnectorSession session, ConnectorTableHandle tableHandle, TupleDomain<ColumnHandle> tupleDomain) { CassandraTableHandle cassandraTableHandle = checkType(tableHandle, CassandraTableHandle.class, "tableHandle"); checkNotNull(tupleDomain, "tupleDomain is null"); CassandraTable table = schemaProvider.getTable(cassandraTableHandle); List<CassandraColumnHandle> partitionKeys = table.getPartitionKeyColumns(); // fetch the partitions List<CassandraPartition> allPartitions = getCassandraPartitions(table, tupleDomain); log.debug( "%s.%s #partitions: %d", cassandraTableHandle.getSchemaName(), cassandraTableHandle.getTableName(), allPartitions.size()); // do a final pass to filter based on fields that could not be used to build the prefix List<ConnectorPartition> partitions = allPartitions .stream() .filter(partition -> tupleDomain.overlaps(partition.getTupleDomain())) .collect(toList()); // All partition key domains will be fully evaluated, so we don't need to include those TupleDomain<ColumnHandle> remainingTupleDomain = TupleDomain.none(); if (!tupleDomain.isNone()) { if (partitions.size() == 1 && ((CassandraPartition) partitions.get(0)).isUnpartitioned()) { remainingTupleDomain = tupleDomain; } else { @SuppressWarnings({"rawtypes", "unchecked"}) List<ColumnHandle> partitionColumns = (List) partitionKeys; remainingTupleDomain = TupleDomain.withColumnDomains( Maps.filterKeys(tupleDomain.getDomains(), not(in(partitionColumns)))); } } // push down indexed column fixed value predicates only for unpartitioned partition which uses // token range query if (partitions.size() == 1 && ((CassandraPartition) partitions.get(0)).isUnpartitioned()) { Map<ColumnHandle, Domain> domains = tupleDomain.getDomains(); List<ColumnHandle> indexedColumns = new ArrayList<>(); // compose partitionId by using indexed column StringBuilder sb = new StringBuilder(); for (Map.Entry<ColumnHandle, Domain> entry : domains.entrySet()) { CassandraColumnHandle column = (CassandraColumnHandle) entry.getKey(); Domain domain = entry.getValue(); if (column.isIndexed() && domain.isSingleValue()) { sb.append(CassandraCqlUtils.validColumnName(column.getName())) .append(" = ") .append( CassandraCqlUtils.cqlValue( toCQLCompatibleString(entry.getValue().getSingleValue()), column.getCassandraType())); indexedColumns.add(column); // Only one indexed column predicate can be pushed down. break; } } if (sb.length() > 0) { CassandraPartition partition = (CassandraPartition) partitions.get(0); TupleDomain<ColumnHandle> filterIndexedColumn = TupleDomain.withColumnDomains( Maps.filterKeys(remainingTupleDomain.getDomains(), not(in(indexedColumns)))); partitions = new ArrayList<>(); partitions.add( new CassandraPartition(partition.getKey(), sb.toString(), filterIndexedColumn, true)); return new ConnectorPartitionResult(partitions, filterIndexedColumn); } } return new ConnectorPartitionResult(partitions, remainingTupleDomain); }