Desktop Application Desktop Application Performance & Optimization 2 — Questions and Answers
Question 1: What is 'garbage collection' and how does it affect desktop application performance?
- Automatic memory management that reclaims unused objects, but can cause brief pauses (Correct answer)
- A background process that removes temporary files from disk
- A feature that closes idle application windows automatically
- A routine that clears the application cache on a schedule
Correct answer: Automatic memory management that reclaims unused objects, but can cause brief pauses
Garbage collection frees memory from objects no longer in use, but collection cycles can cause brief UI freezes in managed runtimes.
Question 2: What is 'database indexing' and why is it important for desktop applications with local databases?
- Creating data structures that speed up query lookups at the cost of additional storage (Correct answer)
- Compressing the database file to reduce its size on disk
- Backing up the database automatically at set intervals
- Encrypting sensitive columns within the database
Correct answer: Creating data structures that speed up query lookups at the cost of additional storage
Indexes allow the database engine to find rows quickly without scanning the entire table, dramatically improving query performance.
Question 3: Which approach reduces the time a desktop application takes to render a large list of items?
- Virtual/windowed list rendering that only renders visible items (Correct answer)
- Pre-rendering all items at startup and hiding non-visible ones
- Reducing the font size to fit more items on screen
- Loading all items into memory before displaying the list
Correct answer: Virtual/windowed list rendering that only renders visible items
Virtual list rendering creates only the DOM/UI elements currently visible in the viewport, regardless of how large the total dataset is.
Question 4: What is 'asynchronous I/O' and why is it important for desktop application responsiveness?
- Performing file or network operations without blocking the UI thread (Correct answer)
- Writing files twice for redundancy
- Reading and writing files simultaneously
- Batching multiple file writes into a single operation
Correct answer: Performing file or network operations without blocking the UI thread
Asynchronous I/O allows file or network operations to proceed in the background while the UI thread remains free to handle user input.
Question 5: What is 'JIT compilation' and how does it benefit desktop application performance?
- Compiling code to native machine instructions at runtime for faster execution than interpretation (Correct answer)
- Downloading and installing updates just in time before launching
- Loading application modules exactly when they are first needed
- Compressing code before storing it in memory
Correct answer: Compiling code to native machine instructions at runtime for faster execution than interpretation
JIT compilation converts intermediate bytecode to optimized native code at runtime, providing near-native performance for managed languages.
Question 6: What is a 'thread pool' in desktop application architecture?
- A collection of pre-created worker threads reused for background tasks to avoid thread creation overhead (Correct answer)
- A group of CPU cores dedicated exclusively to one application
- A set of backup threads that activate when the main thread crashes
- A pool of database connections shared across the application
Correct answer: A collection of pre-created worker threads reused for background tasks to avoid thread creation overhead
Thread pools maintain ready-to-use threads, eliminating the expensive overhead of creating and destroying threads for every short task.
Desktop Application Desktop Application Performance & Optimization 2
What is 'garbage collection' and how does it affect desktop application performance?