qdrant/docs/wal.md

What guarantees should be provided:

• Once data is submitter successfully, it should not be lost (assuming power loss didn't happened in given persistence time interval).
• While indexing, power loss may appear in any moment. Index should not be corrupted.
• All submitted data should eventually be available.

graph TB
	request --> WAL
	WAL --> indexer
	subgraph collections
		register
		segments
	end
	searchers>searchers] -- read --> register
	indexer>indexer] -- write --> register
	register -- owns --> segments

Update stages

Initial structure

graph LR
	collection -- names -->register
	subgraph collection1
		subgraph segment1
			meta1 --> raw_data1
			meta1 --> index1
			index1 -.- raw_data1
		end
		subgraph segment2
			meta2 --> raw_data2
			meta2 --> index2
			index2 -.- raw_data2
		end
		register --> meta1
		register --> meta2
	end

Update

What could be updated?

• Alter labels (Update or delete)
  • It involves index update + statistics update
• Insert new point
• Delete point
• Rename collection
• Optimize \ merge segments
• Collection dropped
• Collection created