On 5/26/2017 11:00 AM, Jaroslaw Rozanski wrote: > What is the impact of changing "precisionStep" without re-indexing > document preceding the change? > > Scenario: > > Assume you have index with field: > <field name="event" type="tdate" indexed="true" stored="true"/> > <fieldType name="tdate" class="solr.TrieDateField" precisionStep="6" > positionIncrementGap="0"/> > > So `tdate` of precision 6. Now let's assume you were to change `tdate` > to be of precision 8. > > According to [1] the change will affect how many terms will be stored in > index after type change is in place. > > But will that affect queries and sorting if index contains documents > with date precisionStep 6 and 8 at the same time?
Some queries could mysteriously stop working correctly, in a way that might take a long time to notice. I'm pretty sure that the precisionStep is used in the query process, to speed up the queries based on the step indicated in the schema. The values searched first (at higher tiers) could be way off what's correct for the documents indexed with a different step. At query time, Solr can only go by what's in the schema, it doesn't look at the index when it is putting its queries together. At a minimum, this could mean you won't get some results that match your query, particularly for range queries, but if the planets align just right, I can also imagine it including at least one document that shouldn't be there. I've got no idea about how it might affect sorting. My instinct says that it won't affect sorting, but I do not actually know. You should definitely completely reindex. This is probably one situation where deleting the entire index and restarting is NOT required, but if it were me, that is the way I'd do it. Thanks, Shawn
