What is the limit for KV Store collection batch update?

[twinspop]

This will be a self-answered question. It doesn't appear to be in answers anywhere, so I'm adding it myself.

When updating a collection, if you exceed the limit of entries in one request, you will receive this error:

Request exceeds API limits - see limits.conf for details. (Too many documents for a single batch save.)

What is the default limit? What are the stanza and key to change it?

[twinspop · Accepted solution]

The limit is controlled by the kvstore stanza in limits.conf. The key is max_queries_per_batch.

[kvstore]
max_queries_per_batch = 1000