Hi Leandro Freitas,

Thanks for the report! Yes, it seems we failed to update the documentation a long time ago (https://github.com/hibernate/hibernate-search/commit/46f5f5c70094265e338a76f9725dbbf10a64ad3b, while developing 5.0.0).

The current implementation of BigDecimalFieldBridge (and the one that should be in the documentation) is still in our tests, and it looks a lot like yours (though you dropped the "storeFactor"): https://github.com/hibernate/hibernate-search/blob/6dfbb22d3dc3093f6c4231a7601fc08afc5c1476/engine/src/test/java/org/hibernate/search/test/engine/numeric/BigDecimalNumericFieldBridge.java#L19-L18

If you want to submit a PR, I'll be glad to merge it. I think we should keep the changes to a minimum though, simply updating the code and stating that implementing MetadataProvidingFieldBridge is necessary so that Hibernate Search knows the field should be treated as numeric when querying/sorting. There's a lot more we could improve in the documentation, but we'll have to rewrite a big part of it in 6.0, so any improvement now would be a short-lived one.