ASP.NET Core Interview Question #194

Why is pagination important for performance?

Performance, Caching & HTTP Senior Advanced

Quick Interview Answer

Pagination limits the amount of data retrieved, processed, serialized, transferred, and rendered in a single request. Returning thousands of records at once increases database load, memory usage, network traffic, and response time.

Detailed Explanation

Offset pagination using Skip and Take is straightforward, but very deep offsets can become expensive on large datasets. Keyset or seek pagination can be more efficient when navigating sequentially through large ordered datasets.

Stable ordering is essential for predictable pagination.

Code Example

const int pageSize = 25;

var products = await db.Products
    .AsNoTracking()
    .OrderBy(p => p.Id)
    .Skip((page - 1) * pageSize)
    .Take(pageSize)
    .ToListAsync(cancellationToken);