diff --git a/age--1.6.0--y.y.y.sql b/age--1.6.0--y.y.y.sql
index 2d693a433..c5a31b373 100644
--- a/age--1.6.0--y.y.y.sql
+++ b/age--1.6.0--y.y.y.sql
@@ -51,3 +51,100 @@ CREATE FUNCTION ag_catalog._ag_enforce_edge_uniqueness4(graphid, graphid, graphi
     STABLE
 PARALLEL SAFE
 as 'MODULE_PATHNAME';
+
+-- Create indexes on id columns for existing labels
+-- Vertex labels get PRIMARY KEY on id, Edge labels get indexes on start_id/end_id
+DO $$
+DECLARE
+    label_rec record;
+    schema_name text;
+    table_name text;
+    idx_exists boolean;
+    pk_exists boolean;
+    idx_name text;
+BEGIN
+    FOR label_rec IN
+        SELECT l.relation, l.kind
+        FROM ag_catalog.ag_label l
+    LOOP
+        SELECT n.nspname, c.relname INTO schema_name, table_name
+        FROM pg_class c
+        JOIN pg_namespace n ON c.relnamespace = n.oid
+        WHERE c.oid = label_rec.relation;
+
+        IF label_rec.kind = 'e' THEN
+            -- Edge: check/create index on start_id
+            SELECT EXISTS (
+                SELECT 1 FROM pg_index i
+                JOIN pg_class c ON c.oid = i.indexrelid
+                JOIN pg_am am ON am.oid = c.relam
+                JOIN pg_attribute a ON a.attrelid = i.indrelid AND a.attnum = i.indkey[0]
+                WHERE i.indrelid = label_rec.relation
+                  AND a.attname = 'start_id'
+                  AND i.indpred IS NULL              -- not a partial index
+                  AND i.indexprs IS NULL             -- not an expression index
+                  AND am.amname = 'btree'            -- btree access method
+            ) INTO idx_exists;
+
+            IF NOT idx_exists THEN
+                EXECUTE format('CREATE INDEX %I ON %I.%I USING btree (start_id)',
+                    table_name || '_start_id_idx', schema_name, table_name);
+            END IF;
+
+            -- Edge: check/create index on end_id
+            SELECT EXISTS (
+                SELECT 1 FROM pg_index i
+                JOIN pg_class c ON c.oid = i.indexrelid
+                JOIN pg_am am ON am.oid = c.relam
+                JOIN pg_attribute a ON a.attrelid = i.indrelid AND a.attnum = i.indkey[0]
+                WHERE i.indrelid = label_rec.relation
+                  AND a.attname = 'end_id'
+                  AND i.indpred IS NULL              -- not a partial index
+                  AND i.indexprs IS NULL             -- not an expression index
+                  AND am.amname = 'btree'            -- btree access method
+            ) INTO idx_exists;
+
+            IF NOT idx_exists THEN
+                EXECUTE format('CREATE INDEX %I ON %I.%I USING btree (end_id)',
+                    table_name || '_end_id_idx', schema_name, table_name);
+            END IF;
+        ELSE
+            -- Vertex: check/create PRIMARY KEY on id
+            SELECT EXISTS (
+                SELECT 1 FROM pg_constraint
+                WHERE conrelid = label_rec.relation AND contype = 'p'
+            ) INTO pk_exists;
+
+            IF NOT pk_exists THEN
+                -- Check if a usable unique index on id already exists
+                SELECT c.relname INTO idx_name
+                FROM pg_index i
+                JOIN pg_class c ON c.oid = i.indexrelid
+                JOIN pg_am am ON am.oid = c.relam
+                WHERE i.indrelid = label_rec.relation
+                  AND i.indisunique = true
+                  AND i.indpred IS NULL              -- not a partial index
+                  AND i.indexprs IS NULL             -- not an expression index
+                  AND am.amname = 'btree'            -- btree access method
+                  AND i.indnkeyatts = 1              -- single column index
+                  AND EXISTS (
+                      SELECT 1 FROM pg_attribute a
+                      WHERE a.attrelid = i.indrelid
+                        AND a.attnum = i.indkey[0]
+                        AND a.attname = 'id'
+                  )
+                LIMIT 1;
+
+                IF idx_name IS NOT NULL THEN
+                    -- Reuse existing unique index for primary key
+                    EXECUTE format('ALTER TABLE %I.%I ADD CONSTRAINT %I PRIMARY KEY USING INDEX %I',
+                        schema_name, table_name, table_name || '_pkey', idx_name);
+                ELSE
+                    -- Create new primary key
+                    EXECUTE format('ALTER TABLE %I.%I ADD PRIMARY KEY (id)',
+                        schema_name, table_name);
+                END IF;
+            END IF;
+        END IF;
+    END LOOP;
+END $$;