Clean up documentation and remove unused code

- Update README.md to remove references to deleted files (setup-postgres-lambda.sql and test-lambda.sh)
- Add information about synchronous Lambda invocation in PostgreSQL to Lambda flow
- Remove unused parameter group from RDS cluster configuration
- Remove test property from custom resource as it's not needed
- Remove outdated SUMMARY.md file that's no longer relevant

Author: kaiz-io

typescript/postgres-lambda/README.md

@@ -80,12 +80,7 @@ No manual setup required! 🎉
 
 ### Test Lambda → PostgreSQL
 
-Using the provided test script:
-```bash
-./test-lambda.sh --function-name <LAMBDA_TO_POSTGRES_FUNCTION_NAME> --message "Hello World"
-```
-
-Or using AWS CLI directly:
+Using AWS CLI directly:
 ```bash
 aws lambda invoke \
   --function-name <LAMBDA_TO_POSTGRES_FUNCTION_NAME> \
@@ -129,8 +124,9 @@ SELECT validate_data('{"id": 789, "value": "valid data"}'::JSONB);
 
 1. **Extension Setup**: Uses `aws_lambda` extension for Lambda invocation (automated)
 2. **Function Creation**: SQL functions wrap Lambda calls with proper ARN construction (automated)
-3. **Event Processing**: Lambda receives structured JSON events from PostgreSQL
-4. **Result Return**: Lambda response becomes available in SQL query results
+3. **Synchronous Invocation**: Uses 'RequestResponse' invocation type for immediate results
+4. **Event Processing**: Lambda receives structured JSON events from PostgreSQL
+5. **Result Return**: Lambda response becomes available in SQL query results
 
 ## Project Structure
 
@@ -142,8 +138,6 @@ SELECT validate_data('{"id": 789, "value": "valid data"}'::JSONB);
 │   ├── postgres-to-lambda/ # Lambda called by PostgreSQL
 │   └── postgres-setup/     # Lambda for automated setup
 ├── test/                   # Unit tests
-├── setup-postgres-lambda.sql # Reference SQL (now automated)
-├── test-lambda.sh         # Lambda testing script
 ├── .yarn/                 # Yarn 2+ configuration
 └── README.md              # This file
 ```

typescript/postgres-lambda/SUMMARY.md

@@ -16,13 +16,6 @@ export class PostgresLambdaStack extends cdk.Stack {
       maxAzs: 2,
       natGateways: 1,
     });
-    const parameterGroup = new rds.ParameterGroup(this, 'PGClusterParamGroup', {
-      engine: rds.DatabaseClusterEngine.auroraPostgres({
-        version: rds.AuroraPostgresEngineVersion.VER_17_4
-      }),
-      parameters: {
-      },
-    });
 
     // Create a PostgreSQL Aurora Serverless v2 cluster
     const dbCluster = new rds.DatabaseCluster(this, 'PostgresCluster', {
@@ -35,7 +28,6 @@ export class PostgresLambdaStack extends cdk.Stack {
       serverlessV2MaxCapacity: 1,
       defaultDatabaseName: 'demodb',
       credentials: rds.Credentials.fromGeneratedSecret('postgres'),
-      parameterGroup: parameterGroup,
     });
 
 
@@ -144,9 +136,6 @@ export class PostgresLambdaStack extends cdk.Stack {
 
     new cdk.CustomResource(this, 'PostgresSetupResource', {
       serviceToken: setupProvider.serviceToken,
-      properties: {
-        test: 'yo'
-      },
     });
 
     // Output the database endpoint and secret ARN