Fix: Support Alias Fields in MIN, MAX, FIRST, LAST, and TAKE Aggregations

integ-test/src/test/java/org/opensearch/sql/calcite/remote/CalciteAliasFieldAggregationIT.java

@@ -0,0 +1,158 @@
+/*
+ * Copyright OpenSearch Contributors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package org.opensearch.sql.calcite.remote;
+
+import static org.opensearch.sql.util.MatcherUtils.rows;
+import static org.opensearch.sql.util.MatcherUtils.schema;
+import static org.opensearch.sql.util.MatcherUtils.verifyDataRows;
+import static org.opensearch.sql.util.MatcherUtils.verifySchema;
+import static org.opensearch.sql.util.MatcherUtils.verifySchemaInOrder;
+
+import java.io.IOException;
+import java.util.List;
+import org.json.JSONObject;
+import org.junit.jupiter.api.Test;
+import org.opensearch.client.Request;
+import org.opensearch.client.ResponseException;
+import org.opensearch.sql.ppl.PPLIntegTestCase;
+
+/**
+ * Integration tests for aggregation functions (MIN, MAX, FIRST, LAST, TAKE) with alias fields.
+ * Tests the fix for issue #4595.
+ */
+public class CalciteAliasFieldAggregationIT extends PPLIntegTestCase {
+
+  private static final String TEST_INDEX_ALIAS = "test_alias_bug";
+
+  @Override
+  public void init() throws Exception {
+    super.init();
+    enableCalcite();
+    createTestIndexWithAliasFields();
+  }
+
+  /**
+   * Create test index with alias fields mapping and insert sample data. This mirrors the
+   * reproduction steps from issue #4595.
+   */
+  private void createTestIndexWithAliasFields() throws IOException {
+    // Delete the index if it exists (for test isolation)
+    try {
+      Request deleteIndex = new Request("DELETE", "/" + TEST_INDEX_ALIAS);
+      client().performRequest(deleteIndex);
+    } catch (ResponseException e) {
+      // Index doesn't exist, which is fine
+    }
+
+    // Create index with alias fields
+    Request createIndex = new Request("PUT", "/" + TEST_INDEX_ALIAS);
+    createIndex.setJsonEntity(
+        "{\n"
+            + "  \"mappings\": {\n"
+            + "    \"properties\": {\n"
+            + "      \"created_at\": {\"type\": \"date\"},\n"
+            + "      \"@timestamp\": {\"type\": \"alias\", \"path\": \"created_at\"},\n"
+            + "      \"value\": {\"type\": \"integer\"},\n"
+            + "      \"value_alias\": {\"type\": \"alias\", \"path\": \"value\"}\n"
+            + "    }\n"
+            + "  }\n"
+            + "}");
+    client().performRequest(createIndex);
+
+    // Insert test documents
+    Request bulkRequest = new Request("POST", "/" + TEST_INDEX_ALIAS + "/_bulk?refresh=true");
+    bulkRequest.setJsonEntity(
+        "{\"index\":{}}\n"
+            + "{\"created_at\": \"2024-01-01T10:00:00Z\", \"value\": 100}\n"
+            + "{\"index\":{}}\n"
+            + "{\"created_at\": \"2024-01-02T10:00:00Z\", \"value\": 200}\n"
+            + "{\"index\":{}}\n"
+            + "{\"created_at\": \"2024-01-03T10:00:00Z\", \"value\": 300}\n");
+    client().performRequest(bulkRequest);
+  }
+
+  @Test
+  public void testMinWithDateAliasField() throws IOException {
+    JSONObject actual =
+        executeQuery(String.format("source=%s | stats MIN(@timestamp)", TEST_INDEX_ALIAS));
+    verifySchema(actual, schema("MIN(@timestamp)", "timestamp"));
+    verifyDataRows(actual, rows("2024-01-01 10:00:00"));
+  }
+
+  @Test
+  public void testMaxWithDateAliasField() throws IOException {
+    JSONObject actual =
+        executeQuery(String.format("source=%s | stats MAX(@timestamp)", TEST_INDEX_ALIAS));
+    verifySchema(actual, schema("MAX(@timestamp)", "timestamp"));
+    verifyDataRows(actual, rows("2024-01-03 10:00:00"));
+  }
+
+  @Test
+  public void testMinMaxWithNumericAliasField() throws IOException {
+    JSONObject actual =
+        executeQuery(
+            String.format(
+                "source=%s | stats MIN(value_alias), MAX(value_alias)", TEST_INDEX_ALIAS));
+    verifySchemaInOrder(
+        actual, schema("MIN(value_alias)", "int"), schema("MAX(value_alias)", "int"));
+    verifyDataRows(actual, rows(100, 300));
+  }
+
+  @Test
+  public void testFirstWithAliasField() throws IOException {
+    JSONObject actual =
+        executeQuery(
+            String.format(
+                "source=%s | sort @timestamp | stats FIRST(@timestamp)", TEST_INDEX_ALIAS));
+    verifySchema(actual, schema("FIRST(@timestamp)", "timestamp"));
+    verifyDataRows(actual, rows("2024-01-01 10:00:00"));
+  }
+
+  @Test
+  public void testLastWithAliasField() throws IOException {
+    JSONObject actual =
+        executeQuery(
+            String.format(
+                "source=%s | sort @timestamp | stats LAST(@timestamp)", TEST_INDEX_ALIAS));
+    verifySchema(actual, schema("LAST(@timestamp)", "timestamp"));
+    verifyDataRows(actual, rows("2024-01-03 10:00:00"));
+  }
+
+  @Test
+  public void testTakeWithAliasField() throws IOException {
+    JSONObject actual =
+        executeQuery(
+            String.format(
+                "source=%s | sort @timestamp | stats TAKE(@timestamp, 2)", TEST_INDEX_ALIAS));
+    verifySchema(actual, schema("TAKE(@timestamp, 2)", "array"));
+    verifyDataRows(actual, rows(List.of("2024-01-01T10:00:00.000Z", "2024-01-02T10:00:00.000Z")));
+  }
+
+  @Test
+  public void testAggregationsWithOriginalFieldsStillWork() throws IOException {
+    JSONObject actual =
+        executeQuery(
+            String.format("source=%s | stats MIN(created_at), MAX(value)", TEST_INDEX_ALIAS));
+    verifySchemaInOrder(
+        actual, schema("MIN(created_at)", "timestamp"), schema("MAX(value)", "int"));
+    verifyDataRows(actual, rows("2024-01-01 10:00:00", 300));
+  }
+
+  @Test
+  public void testUnaffectedAggregationsWithAliasFields() throws IOException {
+    JSONObject actual =
+        executeQuery(
+            String.format(
+                "source=%s | stats SUM(value_alias), AVG(value_alias), COUNT(value_alias)",
+                TEST_INDEX_ALIAS));
+    verifySchemaInOrder(
+        actual,
+        schema("SUM(value_alias)", "bigint"),
+        schema("AVG(value_alias)", "double"),
+        schema("COUNT(value_alias)", "bigint"));
+    verifyDataRows(actual, rows(600, 200.0, 3));
+  }
+}

integ-test/src/test/java/org/opensearch/sql/calcite/remote/CalciteExplainIT.java

@@ -641,10 +641,10 @@ public void testExplainRegexMatchInEvalWithOutScriptPushdown() throws IOExceptio
   // Only for Calcite
   @Test
   public void testExplainOnEarliestLatest() throws IOException {
-    String expected = loadExpectedPlan("explain_earliest_latest.json");
-    assertJsonEqualsIgnoreId(
+    String expected = loadExpectedPlan("explain_earliest_latest.yaml");
+    assertYamlEqualsIgnoreId(
         expected,
-        explainQueryToString(
+        explainQueryYaml(
             String.format(
                 "source=%s | stats earliest(message) as earliest_message, latest(message) as"
                     + " latest_message by server",
@@ -654,10 +654,10 @@ public void testExplainOnEarliestLatest() throws IOException {
   // Only for Calcite
   @Test
   public void testExplainOnEarliestLatestWithCustomTimeField() throws IOException {
-    String expected = loadExpectedPlan("explain_earliest_latest_custom_time.json");
-    assertJsonEqualsIgnoreId(
+    String expected = loadExpectedPlan("explain_earliest_latest_custom_time.yaml");
+    assertYamlEqualsIgnoreId(
         expected,
-        explainQueryToString(
+        explainQueryYaml(
             String.format(
                 "source=%s | stats earliest(message, created_at) as earliest_message,"
                     + " latest(message, created_at) as latest_message by level",
@@ -667,10 +667,10 @@ public void testExplainOnEarliestLatestWithCustomTimeField() throws IOException
   // Only for Calcite
   @Test
   public void testExplainOnFirstLast() throws IOException {
-    String expected = loadExpectedPlan("explain_first_last.json");
-    assertJsonEqualsIgnoreId(
+    String expected = loadExpectedPlan("explain_first_last.yaml");
+    assertYamlEqualsIgnoreId(
         expected,
-        explainQueryToString(
+        explainQueryYaml(
             String.format(
                 "source=%s | stats first(firstname) as first_name, last(firstname) as"
                     + " last_name by gender",
@@ -866,18 +866,18 @@ public void testPushdownLimitIntoAggregation() throws IOException {
 
   @Test
   public void testExplainMaxOnStringField() throws IOException {
-    String expected = loadExpectedPlan("explain_max_string_field.json");
-    assertJsonEqualsIgnoreId(
+    String expected = loadExpectedPlan("explain_max_string_field.yaml");
+    assertYamlEqualsIgnoreId(
         expected,
-        explainQueryToString("source=opensearch-sql_test_index_account | stats max(firstname)"));
+        explainQueryYaml("source=opensearch-sql_test_index_account | stats max(firstname)"));
   }
 
   @Test
   public void testExplainMinOnStringField() throws IOException {
-    String expected = loadExpectedPlan("explain_min_string_field.json");
-    assertJsonEqualsIgnoreId(
+    String expected = loadExpectedPlan("explain_min_string_field.yaml");
+    assertYamlEqualsIgnoreId(
         expected,
-        explainQueryToString("source=opensearch-sql_test_index_account | stats min(firstname)"));
+        explainQueryYaml("source=opensearch-sql_test_index_account | stats min(firstname)"));
   }
 
   @Test

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

@@ -608,10 +608,10 @@ public void testDifferentFilterScriptPushDownBehaviorExplain() throws Exception
 
   @Test
   public void testExplainOnTake() throws IOException {
-    String expected = loadExpectedPlan("explain_take.json");
-    assertJsonEqualsIgnoreId(
+    String expected = loadExpectedPlan("explain_take.yaml");
+    assertYamlEqualsIgnoreId(
         expected,
-        explainQueryToString(
+        explainQueryYaml(
             "source=opensearch-sql_test_index_account | stats take(firstname, 2) as take"));
   }
 

integ-test/src/test/resources/expectedOutput/calcite/explain_earliest_latest.yaml

@@ -0,0 +1,9 @@
+calcite:
+  logical: |
+    LogicalSystemLimit(fetch=[10000], type=[QUERY_SIZE_LIMIT])
+      LogicalProject(earliest_message=[$1], latest_message=[$2], server=[$0])
+        LogicalAggregate(group=[{0}], earliest_message=[ARG_MIN($1, $2)], latest_message=[ARG_MAX($1, $2)])
+          LogicalProject(server=[$1], message=[$3], @timestamp=[$2])
+            CalciteLogicalIndexScan(table=[[OpenSearch, opensearch-sql_test_index_logs]])
+  physical: |
+    CalciteEnumerableIndexScan(table=[[OpenSearch, opensearch-sql_test_index_logs]], PushDownContext=[[AGGREGATION->rel#:LogicalAggregate.NONE.[](input=RelSubset#,group={0},earliest_message=ARG_MIN($1, $2),latest_message=ARG_MAX($1, $2)), PROJECT->[earliest_message, latest_message, server], LIMIT->10000], OpenSearchRequestBuilder(sourceBuilder={"from":0,"size":0,"timeout":"1m","aggregations":{"composite_buckets":{"composite":{"size":1000,"sources":[{"server":{"terms":{"field":"server","missing_bucket":true,"missing_order":"first","order":"asc"}}}]},"aggregations":{"earliest_message":{"top_hits":{"from":0,"size":1,"version":false,"seq_no_primary_term":false,"explain":false,"fields":[{"field":"message.keyword"}],"sort":[{"@timestamp":{"order":"asc"}}]}},"latest_message":{"top_hits":{"from":0,"size":1,"version":false,"seq_no_primary_term":false,"explain":false,"fields":[{"field":"message.keyword"}],"sort":[{"@timestamp":{"order":"desc"}}]}}}}}}, requestedTotalSize=2147483647, pageSize=null, startFrom=0)])

integ-test/src/test/resources/expectedOutput/calcite/explain_earliest_latest_custom_time.yaml

@@ -0,0 +1,9 @@
+calcite:
+  logical: |
+    LogicalSystemLimit(fetch=[10000], type=[QUERY_SIZE_LIMIT])
+      LogicalProject(earliest_message=[$1], latest_message=[$2], level=[$0])
+        LogicalAggregate(group=[{0}], earliest_message=[ARG_MIN($1, $2)], latest_message=[ARG_MAX($1, $2)])
+          LogicalProject(level=[$4], message=[$3], created_at=[$0])
+            CalciteLogicalIndexScan(table=[[OpenSearch, opensearch-sql_test_index_logs]])
+  physical: |
+    CalciteEnumerableIndexScan(table=[[OpenSearch, opensearch-sql_test_index_logs]], PushDownContext=[[AGGREGATION->rel#:LogicalAggregate.NONE.[](input=RelSubset#,group={0},earliest_message=ARG_MIN($1, $2),latest_message=ARG_MAX($1, $2)), PROJECT->[earliest_message, latest_message, level], LIMIT->10000], OpenSearchRequestBuilder(sourceBuilder={"from":0,"size":0,"timeout":"1m","aggregations":{"composite_buckets":{"composite":{"size":1000,"sources":[{"level":{"terms":{"field":"level","missing_bucket":true,"missing_order":"first","order":"asc"}}}]},"aggregations":{"earliest_message":{"top_hits":{"from":0,"size":1,"version":false,"seq_no_primary_term":false,"explain":false,"fields":[{"field":"message.keyword"}],"sort":[{"created_at":{"order":"asc"}}]}},"latest_message":{"top_hits":{"from":0,"size":1,"version":false,"seq_no_primary_term":false,"explain":false,"fields":[{"field":"message.keyword"}],"sort":[{"created_at":{"order":"desc"}}]}}}}}}, requestedTotalSize=2147483647, pageSize=null, startFrom=0)])

integ-test/src/test/resources/expectedOutput/calcite/explain_first_last.yaml

@@ -0,0 +1,9 @@
+calcite:
+  logical: |
+    LogicalSystemLimit(fetch=[10000], type=[QUERY_SIZE_LIMIT])
+      LogicalProject(first_name=[$1], last_name=[$2], gender=[$0])
+        LogicalAggregate(group=[{0}], first_name=[FIRST($1)], last_name=[LAST($1)])
+          LogicalProject(gender=[$4], firstname=[$1])
+            CalciteLogicalIndexScan(table=[[OpenSearch, opensearch-sql_test_index_bank]])
+  physical: |
+    CalciteEnumerableIndexScan(table=[[OpenSearch, opensearch-sql_test_index_bank]], PushDownContext=[[AGGREGATION->rel#:LogicalAggregate.NONE.[](input=RelSubset#,group={0},first_name=FIRST($1),last_name=LAST($1)), PROJECT->[first_name, last_name, gender], LIMIT->10000], OpenSearchRequestBuilder(sourceBuilder={"from":0,"size":0,"timeout":"1m","aggregations":{"composite_buckets":{"composite":{"size":1000,"sources":[{"gender":{"terms":{"field":"gender.keyword","missing_bucket":true,"missing_order":"first","order":"asc"}}}]},"aggregations":{"first_name":{"top_hits":{"from":0,"size":1,"version":false,"seq_no_primary_term":false,"explain":false,"fields":[{"field":"firstname"}]}},"last_name":{"top_hits":{"from":0,"size":1,"version":false,"seq_no_primary_term":false,"explain":false,"fields":[{"field":"firstname"}],"sort":[{"_doc":{"order":"desc"}}]}}}}}}, requestedTotalSize=2147483647, pageSize=null, startFrom=0)])