Disable limit-then-filter pushdown without Calcite

Signed-off-by: Yuanchun Shen <yuanchu@amazon.com>

Author: yuancu

integ-test/src/test/java/org/opensearch/sql/ppl/ExplainIT.java

@@ -111,9 +111,6 @@ public void testLimitPushDownExplain() throws Exception {
 
   @Test
   public void testLimitWithFilterPushdownExplain() throws Exception {
-    // TODO: Fix limit-then-filter pushdown without Calcite
-    //  Currently both limit-then-filter and filter-then-limit have the
-    //  limit-then-filter effect
     String expectedFilterThenLimit =
         isCalciteEnabled()
             ? loadFromFile("expectedOutput/calcite/explain_filter_then_limit_push.json")
@@ -126,6 +123,8 @@ public void testLimitWithFilterPushdownExplain() throws Exception {
                 + "| head 5 "
                 + "| fields age"));
 
+    // The filter in limit-then-filter queries should not be pushed since the current DSL will
+    // execute it as filter-then-limit
     String expectedLimitThenFilter =
         isCalciteEnabled()
             ? loadFromFile("expectedOutput/calcite/explain_limit_then_filter_push.json")
@@ -165,7 +164,7 @@ public void testMultipleLimitExplain() throws Exception {
                 + "| head 5 "
                 + "| fields age"));
 
-    // TODO: Fix limit-filter-limit pushdown without Calcite
+    // The second limit should not be pushed down for limit-filter-limit queries
     String expected10ThenFilterThen5 =
         isCalciteEnabled()
             ? loadFromFile("expectedOutput/calcite/explain_limit_10_filter_5.json")

integ-test/src/test/resources/expectedOutput/ppl/explain_limit_10_filter_5.json

@@ -6,11 +6,28 @@
     },
     "children": [
       {
-        "name": "OpenSearchIndexScan",
+        "name": "LimitOperator",
         "description": {
-          "request": "OpenSearchQueryRequest(indexName=opensearch-sql_test_index_account, sourceBuilder={\"from\":0,\"size\":5,\"timeout\":\"1m\",\"query\":{\"range\":{\"age\":{\"from\":30,\"to\":null,\"include_lower\":false,\"include_upper\":true,\"boost\":1.0}}},\"_source\":{\"includes\":[\"age\"],\"excludes\":[]},\"sort\":[{\"_doc\":{\"order\":\"asc\"}}]}, needClean=true, searchDone=false, pitId=null, cursorKeepAlive=null, searchAfter=null, searchResponse=null)"
+          "limit": 5,
+          "offset": 0
         },
-        "children": []
+        "children": [
+          {
+            "name": "FilterOperator",
+            "description": {
+              "conditions": ">(age, 30)"
+            },
+            "children": [
+              {
+                "name": "OpenSearchIndexScan",
+                "description": {
+                  "request": "OpenSearchQueryRequest(indexName=opensearch-sql_test_index_account, sourceBuilder={\"from\":0,\"size\":10,\"timeout\":\"1m\"}, needClean=true, searchDone=false, pitId=null, cursorKeepAlive=null, searchAfter=null, searchResponse=null)"
+                },
+                "children": []
+              }
+            ]
+          }
+        ]
       }
     ]
   }

integ-test/src/test/resources/expectedOutput/ppl/explain_limit_then_filter_push.json

@@ -6,11 +6,19 @@
     },
     "children": [
       {
-        "name": "OpenSearchIndexScan",
+        "name": "FilterOperator",
         "description": {
-          "request": "OpenSearchQueryRequest(indexName=opensearch-sql_test_index_account, sourceBuilder={\"from\":0,\"size\":5,\"timeout\":\"1m\",\"query\":{\"range\":{\"age\":{\"from\":30,\"to\":null,\"include_lower\":false,\"include_upper\":true,\"boost\":1.0}}},\"_source\":{\"includes\":[\"age\"],\"excludes\":[]},\"sort\":[{\"_doc\":{\"order\":\"asc\"}}]}, needClean=true, searchDone=false, pitId=null, cursorKeepAlive=null, searchAfter=null, searchResponse=null)"
+          "conditions": ">(age, 30)"
         },
-        "children": []
+        "children": [
+          {
+            "name": "OpenSearchIndexScan",
+            "description": {
+              "request": "OpenSearchQueryRequest(indexName=opensearch-sql_test_index_account, sourceBuilder={\"from\":0,\"size\":5,\"timeout\":\"1m\"}, needClean=true, searchDone=false, pitId=null, cursorKeepAlive=null, searchAfter=null, searchResponse=null)"
+            },
+            "children": []
+          }
+        ]
       }
     ]
   }

opensearch/src/main/java/org/opensearch/sql/opensearch/storage/scan/OpenSearchIndexScanBuilder.java

@@ -60,6 +60,10 @@ public TableScanOperator build() {
 
   @Override
   public boolean pushDownFilter(LogicalFilter filter) {
+    // Current DSL can not handle limit-then-filter correctly
+    if (isLimitPushedDown) {
+      return false;
+    }
     return delegate.pushDownFilter(filter);
   }