Examples with WindowFunctionSpec org.apache.hadoop.hive.ql.parse.WindowingSpec.WindowFunctionSpec used on opensource projects

Example 6 with WindowFunctionSpec

use of org.apache.hadoop.hive.ql.parse.WindowingSpec.WindowFunctionSpec in project hive by apache.

the class SemanticAnalyzer method doPhase1GetAggregationsFromSelect.

private LinkedHashMap<String, ASTNode> doPhase1GetAggregationsFromSelect(ASTNode selExpr, QB qb, String dest) throws SemanticException {
    // Iterate over the selects search for aggregation Trees.
    // Use String as keys to eliminate duplicate trees.
    LinkedHashMap<String, ASTNode> aggregationTrees = new LinkedHashMap<String, ASTNode>();
    List<ASTNode> wdwFns = new ArrayList<ASTNode>();
    for (int i = 0; i < selExpr.getChildCount(); ++i) {
        ASTNode function = (ASTNode) selExpr.getChild(i);
        if (function.getType() == HiveParser.TOK_SELEXPR || function.getType() == HiveParser.TOK_SUBQUERY_EXPR) {
            function = (ASTNode) function.getChild(0);
        }
        doPhase1GetAllAggregations(function, aggregationTrees, wdwFns, null);
    }
    // window based aggregations are handled differently
    for (ASTNode wdwFn : wdwFns) {
        WindowingSpec spec = qb.getWindowingSpec(dest);
        if (spec == null) {
            queryProperties.setHasWindowing(true);
            spec = new WindowingSpec();
            qb.addDestToWindowingSpec(dest, spec);
        }
        HashMap<String, ASTNode> wExprsInDest = qb.getParseInfo().getWindowingExprsForClause(dest);
        int wColIdx = spec.getWindowExpressions() == null ? 0 : spec.getWindowExpressions().size();
        WindowFunctionSpec wFnSpec = processWindowFunction(wdwFn, (ASTNode) wdwFn.getChild(wdwFn.getChildCount() - 1));
        // If this is a duplicate invocation of a function; don't add to WindowingSpec.
        if (wExprsInDest != null && wExprsInDest.containsKey(wFnSpec.getExpression().toStringTree())) {
            continue;
        }
        wFnSpec.setAlias(wFnSpec.getName() + "_window_" + wColIdx);
        spec.addWindowFunction(wFnSpec);
        qb.getParseInfo().addWindowingExprToClause(dest, wFnSpec.getExpression());
    }
    return aggregationTrees;
}