Why distance score not equal to 0 (searching exactly the same words)

Hi! @Khorppun_Sontipanya !!

Welcome to our community!!

This is the correct behavior.

When you query (“A”) gets vectorized, it will not return the exact same vectors. So some difference is expected on the distance calculation.

Take this example:

import weaviate
from weaviate.util import generate_uuid5

client = weaviate.connect_to_local()

client.collections.delete("Test")
collection = client.collections.get("Test")
collection.data.insert({"text": "example a"}, uuid=generate_uuid5("example a"))
collection.data.insert({"text": "example b"}, uuid=generate_uuid5("example b"))
collection.data.insert({"text": "example c"}, uuid=generate_uuid5("example c"))

Now if I search with nearText:

from weaviate.classes.query import MetadataQuery
for object in collection.query.near_text("example a", return_metadata=MetadataQuery(distance=True)).objects:
    print(object)
    print(object.metadata.distance)

I will not get the 0 distance for a.

If you search using nearObject, or nearVector, then you can get it:

from weaviate.classes.query import MetadataQuery
for object in collection.query.near_object(near_object=generate_uuid5("example a"), return_metadata=MetadataQuery(distance=True)).objects:
    print(object.properties)
    print(object.metadata.distance)

will output:

{‘text’: ‘example a’}
0.0
{‘text’: ‘example b’}
0.05546557903289795
{‘text’: ‘example c’}
0.08070778846740723

Let me know if this helps!

Thanks!