Is there a way to reduce the search index? Our search index table (craft_searchindex) is over 500,000 rows and it takes a few hours to index. We have 11 languages, and each is being fully indexed. It takes a few hours to complete.

Are there any ways we can reduce the search index size (e.g. only one language, or specific sections?
Craft 3:

In Craft 3, a plugin can listen to the Element::EVENT_REGISTER_SEARCHABLE_ATTRIBUTES event to modify the searchable attribute list of an element before it is indexed.

Craft 2:

Currently the answer is no.

Maybe it makes the case for some sort of onBeforeSearchIndex event a plugin could listen to and influence what Craft adds to the search index, but given that manually updating the search index isn't meant to be a common occurrence (Craft keeps them up to date in normal element saving operations), I'd probably add the workflow you're using that requires frequent updates to the feature request.