From 5bf0a0893b3e508383e1fe2558cc54e12147a4f3 Mon Sep 17 00:00:00 2001 From: Guo Xiang Tan Date: Wed, 15 Jul 2020 11:41:45 +0800 Subject: [PATCH] FIX: Search by relevance may return incorrect post number. MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Follow up to d8c796bc4. Note that his change increases query time by around 40% in the following benchmark against `dev.discourse.org` but this is a tradeoff that has to be taken so that relevance search is accurate. ``` require 'benchmark/ips' Benchmark.ips do |x| x.config(time: 10, warmup: 2) x.report("current aggregate search query") do DB.exec <<~SQL SELECT "posts"."id", "posts"."user_id", "posts"."topic_id", "posts"."post_number", "posts"."raw", "posts"."cooked", "posts"."created_at", "posts"."updated_at", "posts"."reply_to_post_number", "posts"."reply_count", "posts"."quote_count", "posts"."deleted_at", "posts"."off_topic_count", "posts"."like_count", "posts"."incoming_link_count", "posts"."bookmark_count", "posts"."score", "posts"."reads", "posts"."post_type", "posts"."sort_order", "posts"."last_editor_id", "posts"."hidden", "posts"."hidden_reason_id", "posts"."notify_moderators_count", "posts"."spam_count", "posts"."illegal_count", "posts"."inappropriate_count", "posts"."last_version_at", "posts"."user_deleted", "posts"."reply_to_user_id", "posts"."percent_rank", "posts"."notify_user_count", "posts"."like_score", "posts"."deleted_by_id", "posts"."edit_reason", "posts"."word_count", "posts"."version", "posts"."cook_method", "posts"."wiki", "posts"."baked_at", "posts"."baked_version", "posts"."hidden_at", "posts"."self_edits", "posts"."reply_quoted", "posts"."via_email", "posts"."raw_email", "posts"."public_version", "posts"."action_code", "posts"."locked_by_id", "posts"."image_upload_id" FROM "posts" JOIN (SELECT *, row_number() over() row_number FROM (SELECT topics.id, min(posts.post_number) post_number FROM "posts" INNER JOIN "post_search_data" ON "post_search_data"."post_id" = "posts"."id" INNER JOIN "topics" ON "topics"."id" = "posts"."topic_id" AND ("topics"."deleted_at" IS NULL) LEFT JOIN categories ON categories.id = topics.category_id WHERE ("posts"."deleted_at" IS NULL) AND "posts"."post_type" IN (1, 2, 3, 4) AND (topics.visible) AND (topics.archetype <> 'private_message') AND (post_search_data.search_data @@ TO_TSQUERY('english', '''postgres'':*ABCD')) AND (categories.id NOT IN ( SELECT categories.id WHERE categories.search_priority = 1 ) ) AND ((categories.id IS NULL) OR (NOT categories.read_restricted)) GROUP BY topics.id ORDER BY MAX(( TS_RANK_CD( post_search_data.search_data, TO_TSQUERY('english', '''postgres'':*ABCD'), 1|32 ) * ( CASE categories.search_priority WHEN 2 THEN 0.6 WHEN 3 THEN 0.8 WHEN 4 THEN 1.2 WHEN 5 THEN 1.4 ELSE CASE WHEN topics.closed THEN 0.9 ELSE 1 END END ) ) ) DESC, topics.bumped_at DESC LIMIT 51 OFFSET 0) xxx) x ON x.id = posts.topic_id AND x.post_number = posts.post_number WHERE ("posts"."deleted_at" IS NULL) ORDER BY row_number; SQL end x.report("current aggregate search query with proper ranking") do DB.exec <<~SQL SELECT "posts"."id", "posts"."user_id", "posts"."topic_id", "posts"."post_number", "posts"."raw", "posts"."cooked", "posts"."created_at", "posts"."updated_at", "posts"."reply_to_post_number", "posts"."reply_count", "posts"."quote_count", "posts"."deleted_at", "posts"."off_topic_count", "posts"."like_count", "posts"."incoming_link_count", "posts"."bookmark_count", "posts"."score", "posts"."reads", "posts"."post_type", "posts"."sort_order", "posts"."last_editor_id", "posts"."hidden", "posts"."hidden_reason_id", "posts"."notify_moderators_count", "posts"."spam_count", "posts"."illegal_count", "posts"."inappropriate_count", "posts"."last_version_at", "posts"."user_deleted", "posts"."reply_to_user_id", "posts"."percent_rank", "posts"."notify_user_count", "posts"."like_score", "posts"."deleted_by_id", "posts"."edit_reason", "posts"."word_count", "posts"."version", "posts"."cook_method", "posts"."wiki", "posts"."baked_at", "posts"."baked_version", "posts"."hidden_at", "posts"."self_edits", "posts"."reply_quoted", "posts"."via_email", "posts"."raw_email", "posts"."public_version", "posts"."action_code", "posts"."locked_by_id", "posts"."image_upload_id" FROM "posts" JOIN (SELECT *, row_number() over() row_number FROM (SELECT subquery.topic_id id, (ARRAY_AGG(subquery.post_number ORDER BY rank DESC, bumped_at DESC))[1] post_number, MAX(subquery.rank) rank, MAX(subquery.bumped_at) bumped_at FROM (SELECT "posts"."id", "posts"."user_id", "posts"."topic_id", "posts"."post_number", "posts"."raw", "posts"."cooked", "posts"."created_at", "posts"."updated_at", "posts"."reply_to_post_number", "posts"."reply_count", "posts"."quote_count", "posts"."deleted_at", "posts"."off_topic_count", "posts"."like_count", "posts"."incoming_link_count", "posts"."bookmark_count", "posts"."score", "posts"."reads", "posts"."post_type", "posts"."sort_order", "posts"."last_editor_id", "posts"."hidden", "posts"."hidden_reason_id", "posts"."notify_moderators_count", "posts"."spam_count", "posts"."illegal_count", "posts"."inappropriate_count", "posts"."last_version_at", "posts"."user_deleted", "posts"."reply_to_user_id", "posts"."percent_rank", "posts"."notify_user_count", "posts"."like_score", "posts"."deleted_by_id", "posts"."edit_reason", "posts"."word_count", "posts"."version", "posts"."cook_method", "posts"."wiki", "posts"."baked_at", "posts"."baked_version", "posts"."hidden_at", "posts"."self_edits", "posts"."reply_quoted", "posts"."via_email", "posts"."raw_email", "posts"."public_version", "posts"."action_code", "posts"."locked_by_id", "posts"."image_upload_id", ( TS_RANK_CD( post_search_data.search_data, TO_TSQUERY('english', '''postgres'':*ABCD'), 1|32 ) * ( CASE categories.search_priority WHEN 2 THEN 0.6 WHEN 3 THEN 0.8 WHEN 4 THEN 1.2 WHEN 5 THEN 1.4 ELSE CASE WHEN topics.closed THEN 0.9 ELSE 1 END END ) ) rank, topics.bumped_at bumped_at FROM "posts" INNER JOIN "post_search_data" ON "post_search_data"."post_id" = "posts"."id" INNER JOIN "topics" ON "topics"."id" = "posts"."topic_id" AND ("topics"."deleted_at" IS NULL) LEFT JOIN categories ON categories.id = topics.category_id WHERE ("posts"."deleted_at" IS NULL) AND "posts"."post_type" IN (1, 2, 3, 4) AND (topics.visible) AND (topics.archetype <> 'private_message') AND (post_search_data.search_data @@ TO_TSQUERY('english', '''postgres'':*ABCD')) AND (categories.id NOT IN ( SELECT categories.id WHERE categories.search_priority = 1 ) ) AND ((categories.id IS NULL) OR (NOT categories.read_restricted))) subquery GROUP BY subquery.topic_id ORDER BY rank DESC, bumped_at DESC LIMIT 51 OFFSET 0) xxx) x ON x.id = posts.topic_id AND x.post_number = posts.post_number WHERE ("posts"."deleted_at" IS NULL) ORDER BY row_number; SQL end x.compare! end ``` ``` Warming up -------------------------------------- current aggregate search query 1.000 i/100ms current aggregate search query with proper ranking 1.000 i/100ms Calculating ------------------------------------- current aggregate search query 18.040 (± 0.0%) i/s - 181.000 in 10.035241s current aggregate search query with proper ranking 12.992 (± 0.0%) i/s - 130.000 in 10.007214s Comparison: current aggregate search query: 18.0 i/s current aggregate search query with proper ranking: 13.0 i/s - 1.39x (± 0.00) slower ``` --- lib/search.rb | 25 +++++++++++++++++-------- spec/components/search_spec.rb | 6 +++++- 2 files changed, 22 insertions(+), 9 deletions(-) diff --git a/lib/search.rb b/lib/search.rb index 040f149b460..34893db6d05 100644 --- a/lib/search.rb +++ b/lib/search.rb @@ -896,10 +896,7 @@ class Search if aggregate_search aggregate_relation = Post.unscoped - .select( - "subquery.topic_id id", - "(ARRAY_AGG(subquery.post_number))[1] post_number", - ) + .select("subquery.topic_id id") .group("subquery.topic_id") posts = posts.select(posts.arel.projections) @@ -910,7 +907,10 @@ class Search if aggregate_search aggregate_relation = aggregate_relation - .select("MAX(subquery.created_at) created_at") + .select( + "(ARRAY_AGG(subquery.post_number ORDER BY subquery.created_at DESC))[1] post_number", + "MAX(subquery.created_at) created_at" + ) .order("created_at DESC") end elsif @order == :latest_topic @@ -920,7 +920,10 @@ class Search posts = posts.select("topics.created_at topic_created_at") aggregate_relation = aggregate_relation - .select("MAX(subquery.topic_created_at) topic_created_at") + .select( + "(ARRAY_AGG(subquery.post_number ORDER BY subquery.topic_created_at DESC))[1] post_number", + "MAX(subquery.topic_created_at) topic_created_at" + ) .order("topic_created_at DESC") end elsif @order == :views @@ -930,7 +933,10 @@ class Search posts = posts.select("topics.views topic_views") aggregate_relation = aggregate_relation - .select("MAX(subquery.topic_views) topic_views") + .select( + "(ARRAY_AGG(subquery.post_number ORDER BY subquery.topic_views DESC))[1] post_number", + "MAX(subquery.topic_views) topic_views" + ) .order("topic_views DESC") end elsif @order == :likes @@ -976,7 +982,10 @@ class Search .order("rank DESC", "topic_bumped_at DESC") aggregate_relation = aggregate_relation - .select("MAX(subquery.rank) rank", "MAX(subquery.topic_bumped_at) topic_bumped_at") + .select( + "(ARRAY_AGG(subquery.post_number ORDER BY subquery.rank DESC, subquery.topic_bumped_at DESC))[1] post_number", + "MAX(subquery.rank) rank", "MAX(subquery.topic_bumped_at) topic_bumped_at" + ) .order("rank DESC", "topic_bumped_at DESC") else posts = posts.order("#{data_ranking} DESC", "topics.bumped_at DESC") diff --git a/spec/components/search_spec.rb b/spec/components/search_spec.rb index 075043d8f77..4f3fd88a673 100644 --- a/spec/components/search_spec.rb +++ b/spec/components/search_spec.rb @@ -447,9 +447,13 @@ describe Search do it 'aggregates searches in a topic by returning the post with the highest rank' do post = Fabricate(:post, topic: topic, raw: "this is a play post") - post2 = Fabricate(:post, topic: topic, raw: "play playing played") + post2 = Fabricate(:post, topic: topic, raw: "play play playing played play") post3 = Fabricate(:post, raw: "this is a play post") + 5.times do + Fabricate(:post, topic: topic, raw: "play playing played") + end + results = Search.execute('play') expect(results.posts.map(&:id)).to eq([