Examples with SingleColumn com.facebook.presto.sql.tree.SingleColumn used on opensource projects

Example 11 with SingleColumn

use of com.facebook.presto.sql.tree.SingleColumn in project presto by prestodb.

the class QueryRewriter method rewriteNonStorableColumns.

private Query rewriteNonStorableColumns(Query query, ResultSetMetaData metadata) {
    // Skip if all columns are storable
    List<Type> columnTypes = getColumnTypes(typeManager, metadata);
    if (columnTypes.stream().noneMatch(type -> getColumnTypeRewrite(type).isPresent())) {
        return query;
    }
    // Cannot handle SELECT query with top-level SetOperation
    if (!(query.getQueryBody() instanceof QuerySpecification)) {
        return query;
    }
    QuerySpecification querySpecification = (QuerySpecification) query.getQueryBody();
    List<SelectItem> selectItems = querySpecification.getSelect().getSelectItems();
    // Cannot handle SELECT *
    if (selectItems.stream().anyMatch(AllColumns.class::isInstance)) {
        return query;
    }
    List<SelectItem> newItems = new ArrayList<>();
    checkState(selectItems.size() == columnTypes.size(), "SelectItem count (%s) mismatches column count (%s)", selectItems.size(), columnTypes.size());
    for (int i = 0; i < selectItems.size(); i++) {
        SingleColumn singleColumn = (SingleColumn) selectItems.get(i);
        Optional<Type> columnTypeRewrite = getColumnTypeRewrite(columnTypes.get(i));
        if (columnTypeRewrite.isPresent()) {
            newItems.add(new SingleColumn(new Cast(singleColumn.getExpression(), columnTypeRewrite.get().getTypeSignature().toString()), singleColumn.getAlias()));
        } else {
            newItems.add(singleColumn);
        }
    }
    return new Query(query.getWith(), new QuerySpecification(new Select(querySpecification.getSelect().isDistinct(), newItems), querySpecification.getFrom(), querySpecification.getWhere(), querySpecification.getGroupBy(), querySpecification.getHaving(), querySpecification.getOrderBy(), Optional.empty(), querySpecification.getLimit()), query.getOrderBy(), Optional.empty(), query.getLimit());
}

Example 12 with SingleColumn

use of com.facebook.presto.sql.tree.SingleColumn in project presto by prestodb.

the class LimitQueryDeterminismAnalyzer method populateSelectItems.

/**
 * To check whether all ORDER BY columns are matching between the n-th and the (n+1)-th row, we
 * may need to project additional columns. Takes in the list of SelectItems of the original query
 * and append additional SelectItems to the list.
 *
 * @param selectItems A list of {@link SelectItem} of the original query
 * @param orderBy ORDER BY clause
 * @return the list of column keys to locate ORDER BY columns in the query result
 */
private List<ColumnNameOrIndex> populateSelectItems(List<SelectItem> selectItems, OrderBy orderBy) {
    Set<String> aliases = selectItems.stream().filter(SingleColumn.class::isInstance).map(SingleColumn.class::cast).map(SingleColumn::getAlias).filter(Optional::isPresent).map(Optional::get).map(Identifier::getValue).collect(toImmutableSet());
    ImmutableList.Builder<ColumnNameOrIndex> orderByKeys = ImmutableList.builder();
    for (int i = 0; i < orderBy.getSortItems().size(); i++) {
        Expression sortKey = orderBy.getSortItems().get(i).getSortKey();
        if (sortKey instanceof LongLiteral) {
            // If sortKey is an long literal, it can be referenced by column index.
            orderByKeys.add(ColumnNameOrIndex.forIndex(toIntExact(((LongLiteral) sortKey).getValue()) - 1));
        } else if (sortKey instanceof Identifier && aliases.contains(((Identifier) sortKey).getValue())) {
            // If sortKey is an identifier, it can either be an alias or a column name.
            // It is impossible for two columns to have the same alias as sortKey, since otherwise a SYNTAX_ERROR will be thrown due to sortKey being ambiguous.
            // It is possible that sortKey is both an alias and a column name. In that case, sortKey references the aliased column.
            orderByKeys.add(ColumnNameOrIndex.forName(((Identifier) sortKey).getValue()));
        } else {
            // If the sortKey is non-alias identifier, select the sortKey column, since it might not be selected or it might be aliased.
            // If the sortKey is not an identifier, select the sortKey column.
            String columnName = "$$sort_key$$" + i;
            selectItems.add(new SingleColumn(sortKey, delimitedIdentifier(columnName)));
            orderByKeys.add(ColumnNameOrIndex.forName(columnName));
        }
    }
    return orderByKeys.build();
}

Example 13 with SingleColumn

use of com.facebook.presto.sql.tree.SingleColumn in project presto by prestodb.

the class MapColumnValidator method generateChecksumColumns.

@Override
public List<SingleColumn> generateChecksumColumns(Column column) {
    checkArgument(column.getType() instanceof MapType, "Expect MapType, found %s", column.getType().getDisplayName());
    Type keyType = ((MapType) column.getType()).getKeyType();
    Type valueType = ((MapType) column.getType()).getValueType();
    Expression checksum = functionCall("checksum", column.getExpression());
    Expression keysChecksum = generateArrayChecksum(functionCall("map_keys", column.getExpression()), new ArrayType(keyType));
    Expression valuesChecksum = generateArrayChecksum(functionCall("map_values", column.getExpression()), new ArrayType(valueType));
    Expression mapCardinalityChecksum = functionCall("checksum", functionCall("cardinality", column.getExpression()));
    Expression mapCardinalitySum = new CoalesceExpression(functionCall("sum", functionCall("cardinality", column.getExpression())), new LongLiteral("0"));
    return ImmutableList.of(new SingleColumn(checksum, Optional.of(delimitedIdentifier(getChecksumColumnAlias(column)))), new SingleColumn(keysChecksum, Optional.of(delimitedIdentifier(getKeysChecksumColumnAlias(column)))), new SingleColumn(valuesChecksum, Optional.of(delimitedIdentifier(getValuesChecksumColumnAlias(column)))), new SingleColumn(mapCardinalityChecksum, Optional.of(delimitedIdentifier(getCardinalityChecksumColumnAlias(column)))), new SingleColumn(mapCardinalitySum, Optional.of(delimitedIdentifier(getCardinalitySumColumnAlias(column)))));
}