Remove GetAlias Call (#4981)

Author: aparajita31pandey

integ-test/src/test/java/org/opensearch/sql/sql/PaginationIT.java

@@ -28,6 +28,8 @@ public class PaginationIT extends SQLIntegTestCase {
   public void init() throws IOException {
     loadIndex(Index.CALCS);
     loadIndex(Index.ONLINE);
+    loadIndex(Index.DOG);
+    loadIndex(Index.DOGS2);
   }
 
   @Test
@@ -251,6 +253,45 @@ public void testAlias() throws Exception {
     assertEquals(aliasFilteredResponse.getInt("size"), 4);
   }
 
+  @Test
+  public void testAliasResultConsistency() throws Exception {
+    String aliasName = "alias_dog_consistency";
+
+    // Create an alias that maps to both DOG and DOGS2 indices
+    String createAliasQuery =
+        String.format(
+            "{ \"actions\": [ "
+                + "{ \"add\": { \"index\": \"%s\", \"alias\": \"%s\" } }, "
+                + "{ \"add\": { \"index\": \"%s\", \"alias\": \"%s\" } } "
+                + "] }",
+            Index.DOG.getName(), aliasName, Index.DOGS2.getName(), aliasName);
+    Request createAliasRequest = new Request("POST", "/_aliases");
+    createAliasRequest.setJsonEntity(createAliasQuery);
+    JSONObject aliasResponse = new JSONObject(executeRequest(createAliasRequest));
+    assertTrue(aliasResponse.getBoolean("acknowledged"));
+
+    // Query both indices directly (same indices the alias points to)
+    String directQuery =
+        String.format("SELECT * FROM %s, %s", Index.DOG.getName(), Index.DOGS2.getName());
+    JSONObject directResponse = new JSONObject(executeFetchQuery(directQuery, 10, "jdbc"));
+
+    // Query using alias (which points to the same two indices)
+    String aliasQuery = String.format("SELECT * FROM %s", aliasName);
+    JSONObject aliasQueryResponse = new JSONObject(executeFetchQuery(aliasQuery, 10, "jdbc"));
+
+    assertEquals(directResponse.getInt("size"), aliasQueryResponse.getInt("size"));
+
+    // Clean up alias
+    String deleteAliasQuery =
+        String.format(
+            "{ \"actions\": [ { \"remove\": { \"index\": \"%s\", \"alias\": \"%s\" } }, {"
+                + " \"remove\": { \"index\": \"%s\", \"alias\": \"%s\" } } ] }",
+            Index.DOG.getName(), aliasName, Index.DOGS2.getName(), aliasName);
+    Request deleteAliasRequest = new Request("POST", "/_aliases");
+    deleteAliasRequest.setJsonEntity(deleteAliasQuery);
+    executeRequest(deleteAliasRequest);
+  }
+
   private String executeFetchQuery(String query, int fetchSize, String requestType, String filter)
       throws IOException {
     String endpoint = "/_plugins/_sql?format=" + requestType;

legacy/src/main/java/org/opensearch/sql/legacy/executor/format/SelectResultSet.java

@@ -26,8 +26,6 @@
 import java.util.stream.StreamSupport;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
-import org.opensearch.action.admin.indices.alias.get.GetAliasesRequest;
-import org.opensearch.action.admin.indices.alias.get.GetAliasesResponse;
 import org.opensearch.action.admin.indices.mapping.get.GetFieldMappingsRequest;
 import org.opensearch.action.admin.indices.mapping.get.GetFieldMappingsResponse;
 import org.opensearch.common.document.DocumentField;
@@ -163,11 +161,6 @@ private void populateResultSetFromDefaultCursor(DefaultCursor cursor) {
   private void loadFromEsState(Query query) {
     String indexName = fetchIndexName(query);
     String[] fieldNames = fetchFieldsAsArray(query);
-    GetAliasesResponse getAliasesResponse =
-        client.admin().indices().getAliases(new GetAliasesRequest(indexName)).actionGet();
-    if (getAliasesResponse != null && !getAliasesResponse.getAliases().isEmpty()) {
-      indexName = getAliasesResponse.getAliases().keySet().iterator().next();
-    }
     // Reset boolean in the case of JOIN query where multiple calls to loadFromEsState() are made
     selectAll = isSimpleQuerySelectAll(query) || isJoinQuerySelectAll(query, fieldNames);
 
@@ -180,11 +173,11 @@ private void loadFromEsState(Query query) {
         client.admin().indices().getFieldMappings(request).actionGet();
 
     Map<String, Map<String, FieldMappingMetadata>> mappings = response.mappings();
-    if (mappings.isEmpty() || !mappings.containsKey(indexName)) {
+    if (mappings.isEmpty()) {
       throw new IllegalArgumentException(
           String.format("Index type %s does not exist", query.getFrom()));
     }
-    Map<String, FieldMappingMetadata> typeMappings = mappings.get(indexName);
+    Map<String, FieldMappingMetadata> typeMappings = mappings.values().iterator().next();
 
     this.indexName = this.indexName == null ? indexName : (this.indexName + "|" + indexName);
     this.columns.addAll(