Queries with large character counts in fields

cjcenizal · July 26, 2019, 9:58pm

Thanks Jason! I believe the highlighter is the culprit here. Using highlighter with large fields will always incur performance considerations because it has to load the entire text, analyze it, and search it.

Here's a thread from a user with a similar problem as yours: Highlighting takes long time for large documents.

Here are some solutions to consider:

Set index_options to offsets in the mapping. You'll have to reindex your data to try this solution. This will allow the default unified highlighter to skip the analysis step. See https://www.elastic.co/guide/en/elasticsearch/reference/current/search-request-highlighting.html#offsets-strategy for more info.
Set term_vector to with_position_offsets in the mapping. This also requires reindexing. It will also increase the size of the index significantly. See the above links for more info on this option.
Use the fast vector highlighter by setting your highlighter type to fvh. Use this option in conjunction with the term_vector option. Comes with the same tradeoff. See https://www.elastic.co/guide/en/elasticsearch/reference/current/search-request-highlighting.html#fast-vector-highlighter.