What is the blocks.index

Question

Why is this important, and how is this used by a client.

There's no documentation that describes blocks.index. I understand that it is an index, but from a data management perspective, how is this being used and what happens if this file is deleted

Answer 1

blocks.index file stores an index into the block log file. You can find a block via number quickly in the index and the index will have the location of the block in the block log file.