Storage access patterns in HLD - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to identify the storage access pattern used for sequential reads.

HLD

if access_type == [1]:
    print("Sequential read detected")

Drag options to blanks, or click blank then click option'

Abatch

Brandom

Csequential

Dstreaming

Attempts:

3 left

💡 Hint

Common Mistakes

Confusing sequential with random access.

The term sequential refers to accessing storage in a continuous, ordered manner, which is typical for sequential reads.

2fill in blank

medium

Complete the code to select the best storage type for random access patterns.

HLD

if access_pattern == 'random':
    storage = [1]

Drag options to blanks, or click blank then click option'

Assd

Btape_drive

Coptical_disk

Dmagnetic_tape

Attempts:

3 left

💡 Hint

Common Mistakes

Choosing tape or optical disk which are slow for random access.

SSDs provide fast random access, making them ideal for random access patterns.

3fill in blank

hard

Fix the error in the code that incorrectly identifies batch access pattern.

HLD

if access_pattern == [1]:
    process_batch()

Drag options to blanks, or click blank then click option'

Astreaming

Bbatch

Crandom

Dsequential

Attempts:

3 left

💡 Hint

Common Mistakes

Confusing batch with streaming or sequential.

Batch access means processing data in groups or chunks, so the correct pattern is batch.

4fill in blank

hard

Fill both blanks to complete the dictionary comprehension that maps storage types to their typical access patterns.

HLD

storage_access = {"SSD": [1], "Tape": [2]

Drag options to blanks, or click blank then click option'

A"random"

B"sequential"

C"batch"

D"streaming"

Attempts:

3 left

💡 Hint

Common Mistakes

Swapping the access patterns for SSD and Tape.

SSDs are typically used for random access, while Tape is used for sequential access.

5fill in blank

hard

Fill all three blanks to complete the code that filters storage devices by access pattern and capacity.

HLD

filtered_devices = [device for device in devices if device.access == [1] and device.capacity [2] [3]]

Drag options to blanks, or click blank then click option'

A"sequential"

B>

C1000

D"random"

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong access pattern or comparison operator.

This code filters devices with random access and capacity greater than 1000 units.

Practice

1. Which storage access pattern reads data in the order it is stored, one piece after another?

easy

A. Sequential access

B. Random access

C. Batch access

D. Streaming access

Solution

1. Step 1: Understand sequential access meaning

   Sequential access means reading data in the exact order it is stored, one after another.

2. Step 2: Compare with other patterns

   Random access reads data in any order, batch access reads groups of data, streaming processes data continuously.

3. Final Answer:

   Sequential access -> Option A

4. Quick Check:

   Sequential = ordered reading [OK]

Hint: Sequential means reading data in stored order [OK]

Common Mistakes:

• Confusing random access with sequential
• Thinking batch means single item reading
• Mixing streaming with batch processing

2. Which of the following is the correct description of random access in storage systems?

easy

A. Data is read in fixed-size batches only

B. Data is accessed only once and then discarded

C. Data is streamed continuously without breaks

D. Data can be read or written at any location without following order

Solution

1. Step 1: Define random access

   Random access allows reading or writing data at any position without following a sequence.

2. Step 2: Eliminate incorrect options

   Batch access reads fixed-size groups, streaming is continuous flow, and discarding after one access is not random access.

3. Final Answer:

   Data can be read or written at any location without following order -> Option D

4. Quick Check:

   Random access = any location access [OK]

Hint: Random means any location, no order needed [OK]

Common Mistakes:

• Confusing batch with random access
• Thinking streaming means random access
• Assuming random access is sequential

3. Consider a system that processes logs by reading 1000 entries at once, then writes results back. Which access pattern best describes this?

medium

A. Random access, because entries are accessed individually

B. Streaming access, because data flows continuously

C. Batch access, because data is processed in groups

D. Sequential access, because logs are read in order

Solution

1. Step 1: Identify processing style

   The system reads 1000 entries at once, meaning it processes data in groups or batches.

2. Step 2: Match with access patterns

   Batch access means handling data in fixed-size groups, streaming is continuous single flow, random is unordered, sequential is one by one.

3. Final Answer:

   Batch access, because data is processed in groups -> Option C

4. Quick Check:

   Batch = group processing [OK]

Hint: Batch means processing data in groups [OK]

Common Mistakes:

• Confusing batch with streaming
• Assuming sequential means batch
• Thinking random access fits batch processing

4. A developer implemented streaming access but notices high latency and data loss. What is the most likely cause?

medium

A. Not handling backpressure in the streaming pipeline

B. Reading data sequentially instead of randomly

C. Using batch processing instead of continuous streaming

D. Accessing data in random order causing delays

Solution

1. Step 1: Understand streaming issues

   Streaming requires managing data flow to avoid overload, called backpressure handling.

2. Step 2: Identify cause of latency and loss

   If backpressure is not handled, data can pile up causing delays and loss.

3. Final Answer:

   Not handling backpressure in the streaming pipeline -> Option A

4. Quick Check:

   Streaming needs backpressure control [OK]

Hint: Streaming needs backpressure handling to avoid loss [OK]

Common Mistakes:

• Confusing batch with streaming
• Ignoring backpressure importance
• Assuming random access causes streaming issues

5. You design a video streaming service that must deliver smooth playback and allow users to jump to any timestamp instantly. Which storage access pattern combination is best?

hard

A. Sequential access for playback and batch access for buffering

B. Streaming access for playback and random access for seeking

C. Batch access for playback and sequential access for seeking

D. Random access for playback and streaming access for buffering

Solution

1. Step 1: Analyze playback needs

   Smooth playback requires continuous data flow, which is streaming access.

2. Step 2: Analyze seeking needs

   Jumping to any timestamp instantly requires random access to data at any position.

3. Step 3: Combine patterns for best design

   Use streaming for continuous playback and random access for quick seeking.

4. Final Answer:

   Streaming access for playback and random access for seeking -> Option B

5. Quick Check:

   Playback = streaming, seeking = random [OK]

Hint: Streaming for play, random for jump [OK]

Common Mistakes:

• Using sequential for seeking which is slow
• Confusing batch with streaming for playback
• Ignoring random access need for seeking