How do I prevent documents from being indexed?

Question

How do I prevent documents from being indexed?

Answer

To prevent keys from being indexed, you can create a FILTER at index creation time.

FT.CREATE item_idx ON JSON PREFIX 1 item: FILTER '@__key!="item:2"' SCHEMA id AS id NUMERIC 

Test now adding records:

JSON.SET item:1 $ '{"id":1}'
JSON.SET item:2 $ '{"id":2}'
JSON.SET item:3 $ '{"id":3}'

And verify that FT.INFO item_idx reports the number of indexed keys:

 9) num_docs
10) "2"

You can also verify that an index scan does not return the filtered key:

FT.SEARCH item_idx * RETURN 0
1) (integer) 2
2) "item:1"
3) "item:3"

References

Learn more about the FILTER expression.