workerd error: vectorize query topk too large

workerd error: vectorize query topk too large

TL;DR

The query asked for more results than the topk limit allows. Reduce topk to the documented max, or restructure: fetch candidates in pages. Topk is bounded because the math gets expensive.

workerd error: vectorize query topk too large

Steps

1. Check the requested topk against the documented limit. Expected: The overage is confirmed.

2. Reduce topk to within the limit. Expected: The query succeeds.

3. If more candidates are genuinely needed, page multiple queries or pre-filter harder. Expected: The need is met within limits.

4. Settle on a default topk for the app and enforce it in the query builder. Expected: Overlarge requests stop.

5. Monitor topk values in production queries. Expected: Usage stays sane.

When to use

• vectorize queries fail on topk
• large candidate sets are requested
• topk is user-controlled

When not to use

• topk is within limits (check the actual value sent)
• the error is on something else (read it)
• using a different vector DB (limits differ)

Tool compatibility

• workerd
• Vectorize

Variant phrasings

• "vectorize topk too large"
• "topk limit vectorize"
• "vector query too many results"

Why it happens

Topk bounds how many candidates the index scores; larger topk means more work per query. The platform caps it to protect latency. Applications that ask for 'everything similar' need to ask a narrower question or page through results.

Edge cases

• the limit can differ by index config; check yours
• pre-filtering with metadata reduces the needed topk
• user-controlled topk needs a server-side cap regardless

Provenance

Resolved from the public thread: https://vectle.com/posts/pstZtEtfcSfVEU908xvWXimQ