Apply Fundamental Performance Optimization Techniques MB-500 Practice Questions (Page 4)

Questions 16–20

1. 16application · medium

   A developer is writing a job that processes 50,000 sales order lines. For each line, the job must calculate a discount based on a customer tier and update the line. The current implementation loops through each line and calls a method that queries the customer table each time. The job takes over an hour to run. What should the developer do to improve performance?

   • AKeep the loop but add a display method on the sales line table to compute the discount on the fly.
   • BCreate a temporary table to store the customer tier for each sales line, then loop through the temporary table to update the sales lines.
   • CUse a while select loop but cache the customer record in a variable outside the loop.
   • DReplace the loop with a set-based update that uses a join to the customer table to calculate and update all lines in one statement.
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2. 17application · medium

   A developer wants to cache a list of currency exchange rates that are used across multiple forms and services. The rates are updated once a day. The developer wants to ensure that all users see the same rates and that the cache is refreshed when the rates are updated. What should the developer do?

   • ACreate a temporary table and populate it on each form open.
   • BUse the global cache to store the rates and clear the cache when the rates are updated.
   • CUse a regular table to store the rates and read them on every request.
   • DStore the rates in a static dictionary in a singleton class and refresh it manually.
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4. 18application · medium

   A developer has created a temporary table to hold candidate records for a pricing calculation. The table currently has no indexes. The calculation loops through the temporary table and, for each record, performs a lookup on the same temporary table to find related records. The job is slow. What should the developer do to improve performance?

   • AIncrease the number of records in the temporary table to reduce relative overhead.
   • BConvert the temporary table to a regular table to use database indexes.
   • CUse a while select loop instead of a for loop to iterate the temporary table.
   • DAdd a clustered index on the temporary table's foreign key field used in the lookup.
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5. 19application · medium

   A developer is writing code that processes a small set of 10 customer records. For each customer, the code needs to call an external web service to validate their tax ID, and the validation result must be stored in a local variable for further processing. The web service call is slow and cannot be batched. What is the most appropriate approach for this scenario?

   • AUse a singleton class to cache the web service results and reuse them across all customers
   • BUse a while select loop to fetch each customer and call the web service individually, storing the result in a local variable
   • CCreate a temporary table to store the validation results and use insert_recordset to populate it
   • DUse a set-based query to fetch all customers and then call the web service in a batch using a parallel loop
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6. 20foundation · easy

   Which statement is true about modifying temporary tables in Dynamics 365 Finance and Operations?

   • ATemporary tables can be modified using the same insert, update, and delete operations as regular tables.
   • BTemporary tables are read-only and cannot be modified.
   • CTemporary tables can only be modified using set-based operations.
   • DTemporary tables require a primary key to be modified.
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