Allow deletion of mapping/type if no documents are present

[rossbrower]

I understand that deletion of a type is no longer allowed in 2.x. However, I have a scenario where it would be helpful. I have a dedicated index for percolators which contains mappings from the types which flow into daily indices. These types are not stored in the percolators index so there (presumably) is no way for them to leave corruption behind. If I change a type mapping and the percolator that corresponds to it I now have to delete the entire percolators index? This seems pretty undesirable. Why can't the corruption be avoided or why can't it simply allow the deletion if no documents are stored corresponding to the type being deleted? Either way this seems like a weird limitation and I would appreciate some guidance.

[clintongormley]

Interesting point. I wonder if a better way to solve this would be to have the percolator fetch the mapping from the source index, instead of storing it locally. Not sure if that's possible.

[rossbrower]

That would certainly work for my purposes as writing the mapping twice is a bit redundant. If you are able to percolate a document that lives in a different index it would be more intuitive if the mappings were fetched/cached from the source index.

[martijnvg]

The percolator queries are parsed based on that doc type mapping in the percolator index, so removing that mapping and would make the already added percolator queries invalid. So it is important that the doc type mapping can't be deleted or existing fields to be changed.

The only solution here would be to reindex the all the percolator queries. Once the reindex api is added this will be easier to manage.