A deadlock exists between the memory accounting in the merger and the KV operations that vector indexing does to find the right location for a merged vector in the index. In constructMergeBatch(), we acquire a mutex on memory accounting and hold it until the batch is complete. Part of the encoding process for vector index entries is to do one or more KV operations to find the proper location in the index for the new entry, which can involve taking locks. If there is contention on one of the KV keys, a deadlock can result that is not detectable by KV's deadlock detection.

Jira issue: CRDB-55311