diff --git a/base_model/ddl_v2.sql b/base_model/ddl_v2.sql
index 1139035..e517559 100644
--- a/base_model/ddl_v2.sql
+++ b/base_model/ddl_v2.sql
@@ -40,7 +40,6 @@ CREATE TABLE BASIC.MODEL_GROUP (
 
 CREATE TABLE BASIC.ATTRIBUTE (
 	ID BIGSERIAL PRIMARY KEY,
-	ATTRIBUTE_GROUP_ID BIGINT NOT NULL,
 	ATTRIBUTE VARCHAR(128) NOT NULL DEFAULT '',
 	ATTRIBUTE_NAME VARCHAR(64) NOT NULL DEFAULT '',
 	DATA_TYPE_ID BIGINT NOT NULL,
@@ -49,11 +48,7 @@ CREATE TABLE BASIC.ATTRIBUTE (
 	IS_NOT_NULL SMALLINT NOT NULL DEFAULT -1,
 	DEFAULT_VALUE VARCHAR(64) NOT NULL DEFAULT '',
 	VALUE_RANGE VARCHAR(128) NOT NULL DEFAULT ',',
-	
-	UNIQUE (ATTRIBUTE_GROUP_ID, ATTRIBUTE),
-    UNIQUE (ATTRIBUTE, ATTRIBUTE_NAME),
 
-	FOREIGN KEY (ATTRIBUTE_GROUP_ID) REFERENCES BASIC.ATTRIBUTE_GROUP (ID),
 	FOREIGN KEY (DATA_TYPE_ID) REFERENCES BASIC.DATA_TYPE (ID)
 );