fix(index): attach to existing index when overwrite is false

core/src/main/java/com/redis/vl/index/SearchIndex.java

@@ -947,13 +947,24 @@ public void create(boolean overwrite) {
   }
 
   /**
-   * Create the index with overwrite and drop options
+   * Create the index with overwrite and drop options.
    *
-   * @param overwrite Whether to overwrite an existing index
+   * <p>If the index already exists and {@code overwrite} is false, this attaches to the existing
+   * index and returns without modifying it. If {@code overwrite} is true, the existing index is
+   * dropped (optionally with its data) and recreated.
+   *
+   * @param overwrite Whether to overwrite an existing index; when false, an existing index is left
+   *     intact and attached to
    * @param drop Whether to drop existing data when overwriting
    */
   public void create(boolean overwrite, boolean drop) {
-    if (overwrite && exists()) {
+    if (exists()) {
+      if (!overwrite) {
+        // Index already exists and overwrite is false; attach to the existing index instead
+        // of recreating it (matches Python's create(overwrite=False) early return).
+        log.info("Index {} already exists, not overwriting", getName());
+        return;
+      }
       delete(drop);
     }
 

core/src/test/java/com/redis/vl/index/SearchIndexTest.java

@@ -114,6 +114,40 @@ void shouldRecreateIndex() {
     assertThat(searchIndex.exists()).isTrue();
   }
 
+  @Test
+  @DisplayName("Should attach to an existing index without dropping data when not overwriting")
+  void shouldAttachWhenOverwriteFalseAndIndexExists() {
+    // Given an existing index with a document
+    searchIndex.create();
+    Map<String, Object> document = new HashMap<>();
+    document.put("title", "Redis in Action");
+    searchIndex.addDocument("doc:1", document);
+
+    // When
+    searchIndex.create(false);
+
+    // Then - the index is attached and the existing data is preserved
+    assertThat(searchIndex.exists()).isTrue();
+    assertThat(searchIndex.getDocumentCount()).isEqualTo(1);
+  }
+
+  @Test
+  @DisplayName("Should recreate an index without dropping data when overwriting")
+  void shouldRecreateWhenOverwriteTrueAndIndexExists() {
+    // Given an existing index with a document
+    searchIndex.create();
+    Map<String, Object> document = new HashMap<>();
+    document.put("title", "Redis in Action");
+    searchIndex.addDocument("doc:1", document);
+
+    // When
+    searchIndex.create(true);
+
+    // Then - the index is recreated
+    assertThat(searchIndex.exists()).isTrue();
+    assertThat(searchIndex.getDocumentCount()).isEqualTo(1);
+  }
+
   @Test
   @DisplayName("Should add document to index")
   void shouldAddDocumentToIndex() {