fix: issue apache#9213 substitute ArrayAgg to NthValue to optimize qu…

…ery plan

datafusion/sql/src/expr/mod.rs

@@ -203,9 +203,34 @@ impl<'a, S: ContextProvider> SqlToRel<'a, S> {
             }
 
             SQLExpr::ArrayIndex { obj, indexes } => {
+                fn simplify_array_index_expr(expr: Expr, index: Expr) -> (Expr, bool) {
+                    match &expr {
+                        Expr::AggregateFunction(agg_func) if agg_func.func_def == datafusion_expr::expr::AggregateFunctionDefinition::BuiltIn(AggregateFunction::ArrayAgg) => {
+                            let mut new_args = agg_func.args.clone();
+                            new_args.push(index.clone()); 
+                            (Expr::AggregateFunction(datafusion_expr::expr::AggregateFunction::new(
+                                datafusion_expr::AggregateFunction::NthValue,
+                                new_args, 
+                                agg_func.distinct,
+                                agg_func.filter.clone(),
+                                agg_func.order_by.clone(),
+                            )), true)
+                        },
+                        _ => (expr, false), 
+                    }
+                }
                 let expr =
                     self.sql_expr_to_logical_expr(*obj, schema, planner_context)?;
-                self.plan_indexed(expr, indexes, schema, planner_context)
+                if indexes.len() > 1 {
+                    return self.plan_indexed(expr, indexes, schema, planner_context);
+                }
+                let (new_expr, changed) =
+                    simplify_array_index_expr(expr, self.sql_expr_to_logical_expr(indexes[0].clone(), schema, planner_context)?);
+                if changed {
+                    Ok(new_expr)
+                } else {
+                    self.plan_indexed(new_expr, indexes, schema, planner_context)
+                }
             }
 
             SQLExpr::CompoundIdentifier(ids) => {
@@ -557,7 +582,6 @@ impl<'a, S: ContextProvider> SqlToRel<'a, S> {
             limit,
             within_group,
         } = array_agg;
-
         let order_by = if let Some(order_by) = order_by {
             Some(self.order_by_to_sort_expr(
                 &order_by,
@@ -581,10 +605,14 @@ impl<'a, S: ContextProvider> SqlToRel<'a, S> {
             vec![self.sql_expr_to_logical_expr(*expr, input_schema, planner_context)?];
 
         // next, aggregate built-ins
-        let fun = AggregateFunction::ArrayAgg;
         Ok(Expr::AggregateFunction(expr::AggregateFunction::new(
-            fun, args, distinct, None, order_by,
+            AggregateFunction::ArrayAgg,
+            args,
+            distinct,
+            None,
+            order_by,
         )))
+        // see if we can rewrite it into NTH-VALUE
     }
 
     fn sql_in_list_to_expr(

datafusion/sqllogictest/test_files/agg_func_substitute.slt

@@ -0,0 +1,92 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you 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.
+
+#######
+# Setup test data table
+#######
+statement ok
+CREATE EXTERNAL TABLE multiple_ordered_table (
+  a0 INTEGER,
+  a INTEGER,
+  b INTEGER,
+  c INTEGER,
+  d INTEGER
+)
+STORED AS CSV
+WITH HEADER ROW
+WITH ORDER (a ASC, b ASC)
+WITH ORDER (c ASC)
+LOCATION '../../datafusion/core/tests/data/window_2.csv';
+
+
+query TT
+EXPLAIN SELECT a, ARRAY_AGG(c ORDER BY c)[1] as result
+                        FROM multiple_ordered_table
+                        GROUP BY a;
+----
+logical_plan
+Projection: multiple_ordered_table.a, NTH_VALUE(multiple_ordered_table.c,Int64(1)) ORDER BY [multiple_ordered_table.c ASC NULLS LAST] AS result
+--Aggregate: groupBy=[[multiple_ordered_table.a]], aggr=[[NTH_VALUE(multiple_ordered_table.c, Int64(1)) ORDER BY [multiple_ordered_table.c ASC NULLS LAST]]]
+----TableScan: multiple_ordered_table projection=[a, c]
+physical_plan
+ProjectionExec: expr=[a@0 as a, NTH_VALUE(multiple_ordered_table.c,Int64(1)) ORDER BY [multiple_ordered_table.c ASC NULLS LAST]@1 as result]
+--AggregateExec: mode=FinalPartitioned, gby=[a@0 as a], aggr=[NTH_VALUE(multiple_ordered_table.c,Int64(1))], ordering_mode=Sorted
+----SortExec: expr=[a@0 ASC NULLS LAST]
+------CoalesceBatchesExec: target_batch_size=8192
+--------RepartitionExec: partitioning=Hash([a@0], 4), input_partitions=4
+----------AggregateExec: mode=Partial, gby=[a@0 as a], aggr=[NTH_VALUE(multiple_ordered_table.c,Int64(1))], ordering_mode=Sorted
+------------RepartitionExec: partitioning=RoundRobinBatch(4), input_partitions=1
+--------------CsvExec: file_groups={1 group: [[WORKSPACE_ROOT/datafusion/core/tests/data/window_2.csv]]}, projection=[a, c], output_orderings=[[a@0 ASC NULLS LAST], [c@1 ASC NULLS LAST]], has_header=true
+
+
+query TT
+EXPLAIN SELECT a, NTH_VALUE(c, 1 ORDER BY c) as result
+                        FROM multiple_ordered_table
+                        GROUP BY a;
+----
+logical_plan
+Projection: multiple_ordered_table.a, NTH_VALUE(multiple_ordered_table.c,Int64(1)) ORDER BY [multiple_ordered_table.c ASC NULLS LAST] AS result
+--Aggregate: groupBy=[[multiple_ordered_table.a]], aggr=[[NTH_VALUE(multiple_ordered_table.c, Int64(1)) ORDER BY [multiple_ordered_table.c ASC NULLS LAST]]]
+----TableScan: multiple_ordered_table projection=[a, c]
+physical_plan
+ProjectionExec: expr=[a@0 as a, NTH_VALUE(multiple_ordered_table.c,Int64(1)) ORDER BY [multiple_ordered_table.c ASC NULLS LAST]@1 as result]
+--AggregateExec: mode=FinalPartitioned, gby=[a@0 as a], aggr=[NTH_VALUE(multiple_ordered_table.c,Int64(1))], ordering_mode=Sorted
+----SortExec: expr=[a@0 ASC NULLS LAST]
+------CoalesceBatchesExec: target_batch_size=8192
+--------RepartitionExec: partitioning=Hash([a@0], 4), input_partitions=4
+----------AggregateExec: mode=Partial, gby=[a@0 as a], aggr=[NTH_VALUE(multiple_ordered_table.c,Int64(1))], ordering_mode=Sorted
+------------RepartitionExec: partitioning=RoundRobinBatch(4), input_partitions=1
+--------------CsvExec: file_groups={1 group: [[WORKSPACE_ROOT/datafusion/core/tests/data/window_2.csv]]}, projection=[a, c], output_orderings=[[a@0 ASC NULLS LAST], [c@1 ASC NULLS LAST]], has_header=true
+
+query TT
+EXPLAIN SELECT a, ARRAY_AGG(c ORDER BY c)[1 + 100] as result
+                        FROM multiple_ordered_table
+                        GROUP BY a;
+----
+logical_plan
+Projection: multiple_ordered_table.a, NTH_VALUE(multiple_ordered_table.c,Int64(1) + Int64(100)) ORDER BY [multiple_ordered_table.c ASC NULLS LAST] AS result
+--Aggregate: groupBy=[[multiple_ordered_table.a]], aggr=[[NTH_VALUE(multiple_ordered_table.c, Int64(101)) ORDER BY [multiple_ordered_table.c ASC NULLS LAST] AS NTH_VALUE(multiple_ordered_table.c,Int64(1) + Int64(100)) ORDER BY [multiple_ordered_table.c ASC NULLS LAST]]]
+----TableScan: multiple_ordered_table projection=[a, c]
+physical_plan
+ProjectionExec: expr=[a@0 as a, NTH_VALUE(multiple_ordered_table.c,Int64(1) + Int64(100)) ORDER BY [multiple_ordered_table.c ASC NULLS LAST]@1 as result]
+--AggregateExec: mode=FinalPartitioned, gby=[a@0 as a], aggr=[NTH_VALUE(multiple_ordered_table.c,Int64(1) + Int64(100)) ORDER BY [multiple_ordered_table.c ASC NULLS LAST]], ordering_mode=Sorted
+----SortExec: expr=[a@0 ASC NULLS LAST]
+------CoalesceBatchesExec: target_batch_size=8192
+--------RepartitionExec: partitioning=Hash([a@0], 4), input_partitions=4
+----------AggregateExec: mode=Partial, gby=[a@0 as a], aggr=[NTH_VALUE(multiple_ordered_table.c,Int64(1) + Int64(100)) ORDER BY [multiple_ordered_table.c ASC NULLS LAST]], ordering_mode=Sorted
+------------RepartitionExec: partitioning=RoundRobinBatch(4), input_partitions=1
+--------------CsvExec: file_groups={1 group: [[WORKSPACE_ROOT/datafusion/core/tests/data/window_2.csv]]}, projection=[a, c], output_orderings=[[a@0 ASC NULLS LAST], [c@1 ASC NULLS LAST]], has_header=true