Improve RAG vector classified docs scenario

scenarios/06-rag-vector-classified-docs/sql/00_schema.sql

@@ -1,11 +1,20 @@
 WHENEVER SQLERROR EXIT SQL.SQLCODE
 
-CREATE TABLE dds_rag_chunks (
-  chunk_id        NUMBER GENERATED BY DEFAULT AS IDENTITY PRIMARY KEY,
-  document_title VARCHAR2(160) NOT NULL,
-  department     VARCHAR2(40) NOT NULL,
-  classification VARCHAR2(30) NOT NULL,
-  chunk_text     VARCHAR2(1000) NOT NULL,
-  embedding      VECTOR(3, FLOAT32)
-);
-
+BEGIN
+  EXECUTE IMMEDIATE q'[
+    CREATE TABLE dds_rag_chunks (
+      chunk_id        NUMBER GENERATED BY DEFAULT AS IDENTITY PRIMARY KEY,
+      document_title VARCHAR2(160) NOT NULL,
+      department     VARCHAR2(40) NOT NULL,
+      classification VARCHAR2(30) NOT NULL,
+      chunk_text     VARCHAR2(1000) NOT NULL,
+      embedding      VECTOR(3, FLOAT32)
+    )
+  ]';
+EXCEPTION
+  WHEN OTHERS THEN
+    IF SQLCODE != -955 THEN
+      RAISE;
+    END IF;
+END;
+/