discourse-ai/lib/tasks/modules/embeddings/database.rake

41 lines
1.6 KiB
Ruby

# frozen_string_literal: true
desc "Backfill embeddings for all topics"
task "ai:embeddings:backfill", [:start_topic] => [:environment] do |_, args|
public_categories = Category.where(read_restricted: false).pluck(:id)
strategy = DiscourseAi::Embeddings::Strategies::Truncation.new
vector_rep = DiscourseAi::Embeddings::VectorRepresentations::Base.current_representation(strategy)
table_name = vector_rep.table_name
Topic
.joins("LEFT JOIN #{table_name} ON #{table_name}.topic_id = topics.id")
.where("#{table_name}.topic_id IS NULL")
.where("topics.id >= ?", args[:start_topic].to_i || 0)
.where("category_id IN (?)", public_categories)
.where(deleted_at: nil)
.order("topics.id ASC")
.find_each do |t|
print "."
vector_rep.generate_topic_representation_from(t)
end
end
desc "Creates indexes for embeddings"
task "ai:embeddings:index", [:work_mem] => [:environment] do |_, args|
# Using extension maintainer's recommendation for ivfflat indexes
# Results are not as good as without indexes, but it's much faster
# Disk usage is ~1x the size of the table, so this doubles table total size
count = Topic.count
lists = count < 1_000_000 ? count / 1000 : Math.sqrt(count).to_i
probes = count < 1_000_000 ? lists / 10 : Math.sqrt(lists).to_i
vector_representation_klass = DiscourseAi::Embeddings::Vectors::Base.find_vector_representation
strategy = DiscourseAi::Embeddings::Strategies::Truncation.new
DB.exec("SET work_mem TO '#{args[:work_mem] || "1GB"}';")
vector_representation_klass.new(strategy).create_index(lists, probes)
DB.exec("RESET work_mem;")
DB.exec("SET ivfflat.probes = #{probes};")
end