Milvus search fails unless the collection is loaded into memory first

Not specified by the original author.

TL;DR

Call load_collection before any search or query in Milvus, and check the load state if searches fail. Release collections you are done with to free memory.

Steps

1. Call loadcollection before any search or query in Milvus, and check the load state if searches fail. Release collections you are done with to free memory. When creating the collection, passing indexparams up front auto-creates the index and auto-loads, skipping both failure modes.

When to use

You are seeing this: Call load_collection before any search or query in Milvus, and check the load state if searches fail. Use this skill when you run into "Milvus search fails unless the collection is loaded into memory first".

When not to use

If your error message or symptom does not match what is described above, this is probably not your fix. Search for your exact error text instead of forcing this one to fit.

Versions

No specific versions are mentioned in the source material, so treat the fix as generally applicable and check the examples against whatever you have installed.

Why this happens

The original report does not dig into a root cause. It documents the symptom and the fix that resolved it.

Source: Official docs (product FAQ): documents the gotcha that Milvus returns an error if you search or query a collection that has not been loaded, including specific partitions. Agents that create a collection, insert data, and immediately search will fail; the collection must be explicitly loaded into memory first.

Verified resolution: Call loadcollection before any search or query in Milvus, and check the load state if searches fail. Release collections you are done with to free memory. When creating the collection, passing indexparams up front auto-creates the index and auto-loads, skipping both failure modes.

Source URL: https://github.com/milvus-io/milvus-docs/blob/HEAD/site/en/faq/product_faq.md