Duplicate table names in WSO2 API monetization documentation for Postgres DB - wso2

Question

I was going through the WSO2 documentation to Monetize an API. In the database configuration section, it has been mentioned that we have to execute the provided database script. If we select Postgres, it displays the script to be executed.
However, all the CREATE TABLE statements have the same table name, even though the sequence names are different. For other databases like MySQL, Oracle, etc, the table names are different as well.
Just to be sure, I even checked with older documentation and it's the same even in older documentation. Script for Postgres database:
CREATE SEQUENCE AM_MONETIZATION START WITH 1 INCREMENT BY 1;
CREATE TABLE IF NOT EXISTS AM_POLICY_SUBSCRIPTION (
API_ID INTEGER NOT NULL,
TIER_NAME VARCHAR(512),
STRIPE_PRODUCT_ID VARCHAR(512),
STRIPE_PLAN_ID VARCHAR(512),
FOREIGN KEY (API_ID) REFERENCES AM_API (API_ID) ON DELETE CASCADE
);
CREATE SEQUENCE AM_POLICY_PLAN_MAPPING START WITH 1 INCREMENT BY 1;
CREATE TABLE IF NOT EXISTS AM_POLICY_SUBSCRIPTION (
POLICY_ID INTEGER DEFAULT NEXTVAL('AM_POLICY_PLAN_MAPPING'),
POLICY_UUID VARCHAR(256),
PRODUCT_ID VARCHAR(512),
PLAN_ID VARCHAR(512),
FOREIGN KEY (POLICY_UUID) REFERENCES AM_POLICY_SUBSCRIPTION(UUID)
);
CREATE SEQUENCE AM_MONETIZATION_PLATFORM_CUSTOMERS START WITH 1 INCREMENT BY 1;
CREATE TABLE IF NOT EXISTS AM_POLICY_SUBSCRIPTION (
POLICY_ID INTEGER DEFAULT NEXTVAL('AM_MONETIZATION_PLATFORM_CUSTOMERS'),
ID INTEGER NOT NULL AUTO_INCREMENT,
SUBSCRIBER_ID INTEGER NOT NULL,
TENANT_ID INTEGER NOT NULL,
CUSTOMER_ID VARCHAR(256) NOT NULL,
PRIMARY KEY (ID),
FOREIGN KEY (SUBSCRIBER_ID) REFERENCES AM_SUBSCRIBER(SUBSCRIBER_ID) ON DELETE CASCADE
);
CREATE SEQUENCE AM_MONETIZATION_SHARED_CUSTOMERS START WITH 1 INCREMENT BY 1;
CREATE TABLE IF NOT EXISTS AM_POLICY_SUBSCRIPTION (
POLICY_ID INTEGER DEFAULT NEXTVAL('AM_MONETIZATION_SHARED_CUSTOMERS'),
ID INTEGER NOT NULL AUTO_INCREMENT,
APPLICATION_ID INTEGER NOT NULL,
API_PROVIDER VARCHAR(256) NOT NULL,
TENANT_ID INTEGER NOT NULL,
SHARED_CUSTOMER_ID VARCHAR(256) NOT NULL,
PARENT_CUSTOMER_ID INTEGER NOT NULL,
PRIMARY KEY (ID),
FOREIGN KEY (APPLICATION_ID) REFERENCES AM_APPLICATION(APPLICATION_ID) ON DELETE CASCADE,
FOREIGN KEY (PARENT_CUSTOMER_ID) REFERENCES AM_MONETIZATION_PLATFORM_CUSTOMERS(ID) ON DELETE CASCADE
);
CREATE SEQUENCE AM_MONETIZATION_SUBSCRIPTIONS START WITH 1 INCREMENT BY 1;
CREATE TABLE IF NOT EXISTS AM_POLICY_SUBSCRIPTION (
POLICY_ID INTEGER DEFAULT NEXTVAL('AM_MONETIZATION_SUBSCRIPTIONS'),
ID INTEGER NOT NULL AUTO_INCREMENT,
SUBSCRIBED_APPLICATION_ID INTEGER NOT NULL,
SUBSCRIBED_API_ID INTEGER NOT NULL,
TENANT_ID INTEGER NOT NULL,
SUBSCRIPTION_ID VARCHAR(256) NOT NULL,
SHARED_CUSTOMER_ID INTEGER NOT NULL,
PRIMARY KEY (ID),
FOREIGN KEY (SUBSCRIBED_APPLICATION_ID) REFERENCES AM_APPLICATION(APPLICATION_ID) ON DELETE CASCADE,
FOREIGN KEY (SUBSCRIBED_API_ID) REFERENCES AM_API(API_ID) ON DELETE CASCADE,
FOREIGN KEY (SHARED_CUSTOMER_ID) REFERENCES AM_MONETIZATION_SHARED_CUSTOMERS(ID) ON DELETE CASCADE
);
I changed the table names based on what is used in MySQL script and created a Monetization policy. While I try to subscribe an API to the monetized policy, I am getting the following error:
ERROR - StripeMonetizationDAO Failed to add Stripe platform customer details for Subscriber : 1
ERROR - APIConsumerImpl Could not execute Workflow
org.wso2.carbon.apimgt.impl.workflow.WorkflowException: Error when inserting stripe customer details of username to Database
Caused by: org.postgresql.util.PSQLException: ERROR: null value in column "id" violates not-null constraint
Detail: Failing row contains (3, null, 1, -1234, cus_M7MKkaasfCbdf342SEn).
ERROR - GlobalThrowableMapper Could not execute Workflow
I am not sure if the above errors are due to the table name changes in the script or due to the update in workflow executors. I have added the following in workflow executors:
<SubscriptionCreation executor="<billing-engine-related-SubscriptionCreationWorkflowExecutor>"/>
<SubscriptionDeletion executor="<billing-engine-related-StripeSubscriptionDeletionWorkflowExecutor>"/>

Answer 1

There seems to be several issues with the documented db scripts for postgress and seems like we have missed it. Can you try the following scripts. Please note that i haven't tried it in postgress, but fixed multiple schema issues and this should work.
CREATE TABLE IF NOT EXISTS AM_MONETIZATION (
API_ID INTEGER NOT NULL,
TIER_NAME VARCHAR(512),
STRIPE_PRODUCT_ID VARCHAR(512),
STRIPE_PLAN_ID VARCHAR(512),
FOREIGN KEY (API_ID) REFERENCES AM_API (API_ID) ON DELETE CASCADE
);
CREATE TABLE IF NOT EXISTS AM_POLICY_PLAN_MAPPING (
POLICY_UUID VARCHAR(256),
PRODUCT_ID VARCHAR(512),
PLAN_ID VARCHAR(512),
FOREIGN KEY (POLICY_UUID) REFERENCES AM_POLICY_SUBSCRIPTION(UUID)
);
CREATE SEQUENCE AM_MONETIZATION_PLATFORM_CUSTOMERS_SEQ START WITH 1 INCREMENT BY 1;
CREATE TABLE IF NOT EXISTS AM_MONETIZATION_PLATFORM_CUSTOMERS (
ID INTEGER DEFAULT NEXTVAL('AM_MONETIZATION_PLATFORM_CUSTOMERS_SEQ'),
SUBSCRIBER_ID INTEGER NOT NULL,
TENANT_ID INTEGER NOT NULL,
CUSTOMER_ID VARCHAR(256) NOT NULL,
PRIMARY KEY (ID),
FOREIGN KEY (SUBSCRIBER_ID) REFERENCES AM_SUBSCRIBER(SUBSCRIBER_ID) ON DELETE CASCADE
);
CREATE SEQUENCE AM_MONETIZATION_SHARED_CUSTOMERS_SEQ START WITH 1 INCREMENT BY 1;
CREATE TABLE IF NOT EXISTS AM_MONETIZATION_SHARED_CUSTOMERS (
ID INTEGER DEFAULT NEXTVAL('AM_MONETIZATION_SHARED_CUSTOMERS_SEQ'),
APPLICATION_ID INTEGER NOT NULL,
API_PROVIDER VARCHAR(256) NOT NULL,
TENANT_ID INTEGER NOT NULL,
SHARED_CUSTOMER_ID VARCHAR(256) NOT NULL,
PARENT_CUSTOMER_ID INTEGER NOT NULL,
PRIMARY KEY (ID),
FOREIGN KEY (APPLICATION_ID) REFERENCES AM_APPLICATION(APPLICATION_ID) ON DELETE CASCADE,
FOREIGN KEY (PARENT_CUSTOMER_ID) REFERENCES AM_MONETIZATION_PLATFORM_CUSTOMERS(ID) ON DELETE CASCADE
);
CREATE SEQUENCE AM_MONETIZATION_SUBSCRIPTIONS_SEQ START WITH 1 INCREMENT BY 1;
CREATE TABLE IF NOT EXISTS AM_MONETIZATION_SUBSCRIPTIONS (
ID INTEGER DEFAULT NEXTVAL('AM_MONETIZATION_SUBSCRIPTIONS_SEQ'),
SUBSCRIBED_APPLICATION_ID INTEGER NOT NULL,
SUBSCRIBED_API_ID INTEGER NOT NULL,
TENANT_ID INTEGER NOT NULL,
SUBSCRIPTION_ID VARCHAR(256) NOT NULL,
SHARED_CUSTOMER_ID INTEGER NOT NULL,
PRIMARY KEY (ID),
FOREIGN KEY (SUBSCRIBED_APPLICATION_ID) REFERENCES AM_APPLICATION(APPLICATION_ID) ON DELETE CASCADE,
FOREIGN KEY (SUBSCRIBED_API_ID) REFERENCES AM_API(API_ID) ON DELETE CASCADE,
FOREIGN KEY (SHARED_CUSTOMER_ID) REFERENCES AM_MONETIZATION_SHARED_CUSTOMERS(ID) ON DELETE CASCADE
);