WebSockets are simply a bidirectional communication protocol
Both parties can talk at once instead of client asks, server responds
Indexing is like making a directory of all noted that have certain criteria.
Discussion
I see. It at all what I had imagined.
And yes, I have a vague sense of what indexing does, from having joined some large dbs here and there along the way, and learning it worked faster if I enabled some index option. But I'm sure the details are interesting, and that there's lots of room for different choices that fall under the heading of "indexing".
Not* at all (regarding web socket)