Understanding Ordering in Magic IndexedDB

Published: March 26, 2025

The Key Concept: Intent-Based Ordering vs. Return Ordering

Magic IndexedDB is not a traditional in-memory LINQ provider, nor is it a SQL engine. It’s the world’s first true LINQ-to-IndexedDB translation layer — meaning it interprets your queries as intent, decomposes and optimizes them into efficient IndexedDB calls, and then reassembles the data according to your query semantics.

Your ordering intent is always honored.

If you write .OrderByDescending(x => x.Created).Take(2).Skip(4), that logic is applied correctly during query translation.

But return order is not guaranteed due to performance-first streaming.

Results are often streamed or yielded as they are resolved — eliminating full memory buffering, but also not preserving final sort order.

Why This Happens: Performance & Yield-First Design

Magic IndexedDB was built around performance-first streaming:

Queries are split across indexes, cursors, and compound paths for speed.

Results start returning as soon as possible, with minimal memory overhead.

No in-memory sorting is applied before returning the data.

Full buffering would negate the performance advantages of streaming, especially on large datasets.

What About .ToList() or Non-Yielded Queries?

Some methods like .ToListAsync() buffer results — but Magic IndexedDB applies the same behavior regardless.

Whether you use .ToListAsync() or .AsAsyncEnumerable(), you should assume results will not be sorted on return.

What Should I Do If I Need Ordered Results?

Sort the results in-memory after retrieval. You can rely on the correct filtering, skipping, and taking having been applied.

var result = await db.Items
    .Where(x => x.Type == "Important")
    .OrderByDescending(x => x.Created)
    .Take(10)
    .ToListAsync();

// Reapply ordering in-memory (if needed)
var sorted = result.OrderByDescending(x => x.Created).ToList();

Can I Build a Wrapper That Orders for Me?

Absolutely. Since the universal query format preserves intent, any wrapper or framework built on top can re-apply the order in-memory if needed.

Magic IndexedDB will always prioritize streaming, performance, and early returns — and leave sorting up to your app if needed. But Magic IndexedDB felt it was important to uphold consistency. Whether you utilize the ToListAsync() or the AsAsyncEnumerable() the ordering logic is the same.

Final Thoughts

This is one of the few intentional differences from LINQ-to-SQL — but it’s what gives Magic IndexedDB its high performance and low memory footprint.

Ordering is applied in logic — but not guaranteed in output. Once you understand this, you gain predictable control with incredible performance.