Microsoft Updated MB-820 Exam Questions and Answers by karim

Read Scale-Out:

Read scale-out is a feature in Business Central that allows you to improve performance by distributing read-only queries (such as the ones from the ticketAPI) across multiple read replicas in the cloud database. This reduces the load on the primary database and helps improve the response time for read-intensive operations, like analyzing POS data through the ticketAPI.

Data Access Intent - ReadOnly:

When enabling read scale-out, you can configure the DataAccessIntent property of APIs to be ReadOnly. This directs the system to use read replicas to handle read-only queries, which enhances performance by offloading such queries from the primary database.

Why Not Other Options?

Option A (ODataReadonlyGetEnabled): This parameter is unrelated to read scale-out and primarily affects OData services behavior, not API performance tuning.

Option B (AccessByPermission): Setting the permission to Read does not directly affect the performance. It only controls access based on user permissions.

Option D (DataAccessIntent ReadOnly): While setting this property to ReadOnly helps in read-only operations, enabling read scale-out (option C) ensures the underlying infrastructure is optimized to handle such read operations, which is the fundamental action required.

Reference Documentation:

Read Scale-Out in Business Central

Data Access Intent in AL

codeunit 52102 "POS API Management"

{

Access = Public;

Permissions = TableData "POS Information" = rwdx;

trigger OnRun()

begin

readAPI();

end;

procedure readAPI()

begin

// Your code here to read from the POS API

end;

}

field(3; "Receipt No."; Code[20])

{

DataClassification = CustomerContent;

TableRelation = "Purch. Rcpt. Header"."No." where ("Buy-from Vendor No." = field("Vendor No."));

}

Field Declaration:

The field(3; "Receipt No."; Code[20]) part defines the field in the table with ID 3 and type Code with a length of 20. This field will hold the receipt number.

DataClassification:

CustomerContent is selected for the DataClassification property, which categorizes the data for privacy and compliance management. This aligns with Business Central's recommendations for handling sensitive data in customer-related tables.

TableRelation Property:

The TableRelation property links the "Receipt No." field to another table, which in this case is the "Purch. Rcpt. Header" table. This ensures that only valid receipt numbers from the Purchase Receipt Header table can be selected or entered in this field.

Relation Filter:

The filter condition is applied using the where clause. It ensures that the Receipt No. is only from the Purchase Receipt Header records where the "Buy-from Vendor No." matches the "Vendor No." of the current record.

The condition field("Vendor No.") is selected from the drop-down as shown in the image. This links the vendor information in the non-conformity table to the receipt in the Purchase Receipt Header table.

By linking the "Vendor No." fields, you ensure that only receipt numbers from the correct vendor are available, which improves data consistency and reduces errors during data entry.

References to AL Language:

The TableRelation property is frequently used to create references between tables in Business Central. In this case, the correct relationship between the "Purch. Rcpt. Header" and the Non-conformity table is established using the TableRelation and filter.

Reference Documentation:

AL TableRelation Property

AL Field Syntax