Scott Stults
Category: Uncategorized
Back in 2012 Luca Cavanna opened an issue on the Solr Jirarequesting a field exclusion syntax. Right now it’s the 5th highest-voted ticket, and it’s easy to understand why.Documents consisting of dozens, even hundreds of fields are common and without an exclusion syntax your choices arelimited to:
- All fields (“*”)
- Some fields that match a specific naming convention (“section_*”)
- Each field (“section_1, section_2, section_3”…)
With atomic updates you need to store each field, so unwieldy field lists are quickly becoming the norm.
About a year later Andrea Gazzarini added an excellent patch that went above andbeyond the original request and added a more flexible expression syntax for both exclusions and inclusions. What’s morehe provided excellent documentation about the patchas well. In short, with this patch you can do things like:
- Exclude a single field:
fl=-forbidden_field - Exclude similarly named fields:
fl=-forbidden_* - Use a question mark for a single character wildcard:
fl=-forbidden_5?
I should also mention some of the things you could already do with field lists like supply functions, transformers,and aliases (and aliases to functions and transformers). So when you use wt=csv to generate a report on your indexyou can let Solr do a lot of the busywork for you.
For now this exists only as a patch, so you’ll need to download the source, apply the patch, and build Solr yourself.If you’d like to see this included as part of Solr I encourage you to vote on it!