CS Performance Optimization 4

Question 1

Which tool category is designed to identify which functions consume the most CPU time in a running program?

Accepted Answer

Profiler

Answer

Profilers measure where a program spends time so optimization targets the true hotspots.

Question 2

What is the primary benefit of a connection pool in a database-backed application?

Accepted Answer

Avoiding the overhead of establishing a new connection per request

Answer

Reusing established connections avoids costly repeated handshakes and setup.

Question 3

A tight loop branches unpredictably on random data, causing slowdowns. Which hardware mechanism is being defeated?

Accepted Answer

Branch prediction

Answer

Random branch outcomes cause frequent mispredictions, flushing the pipeline each time.

Question 4

Which database optimization most directly speeds up a frequently run query filtering on a specific column?

Accepted Answer

Creating an index on that column

Answer

An index lets the database locate matching rows without scanning the full table.

Question 5

What trade-off does loop unrolling typically make to improve performance?

Accepted Answer

Larger code size in exchange for fewer branch instructions

Answer

Unrolling replicates the loop body, growing code size but reducing loop-control and branch overhead.

(CS) Computer Science Practice Test