[COUCHDB-1084] Remove unnecessary btree lookup inside couch_db_updater

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Won't Fix
• Affects Version/s: 1.2
• Component/s: Database Core
• Skill Level: Committers Level (Medium to Hard)
• Assignee: Damien Katz
• Reporter: Damien Katz
• Created: 08/Mar/11 02:07
• Updated: 02/Sep/18 06:31
• Resolved: 02/Sep/18 06:31

Description

The CouchDB update process has an unnecessary btree lookup, where it reads the values in bulks, checks for conflicts, writes the docs to disk, updates the values appropriately and writes them to the btree out in a second step. It's possible to avoid this second step, and instead do all the checking, doc writing and value transformation in a single btree lookup, thereby reducing the number of btree traversals and disk IO.