Perché il prefisso di pg_search non funziona come mi aspetto?

Question

Questo è il mio metodo pg_search:

pg_search_scope :node_search, against: [:name, :user_id, :circa, :cached_tagged_user_names, :cached_user_tag_list], 
    using: { tsearch: { any_word: true, dictionary: :english, prefix: true} }, 
    :associated_against => { 
     comments: [:message], 
     user: [:first_name, :last_name, :email], 
     memberships: [:relation], 
     user_tags: [:name] 
    } 

Non il prefix: true per tsearch come il docs recommend.

Tuttavia, almeno in un caso particolare, non funziona come mi aspetto.

Ho un oggetto Node che assomiglia a questo:

=> [#<Node id: 85, name: "House Fire 2", family_tree_id: 57, user_id: 57, media_id: 228, media_type: "Video", created_at: "2015-05-15 00:20:26", updated_at: "2015-06-08 22:25:49", circa: nil, is_comment: nil, cached_votes_total: 0, cached_votes_score: 0, cached_votes_up: 0, cached_votes_down: 0, cached_weighted_score: 0, cached_weighted_total: 0, cached_weighted_average: 0.0, cached_user_tag_list: "danny@test.com, abc@test.com", cached_num_user_tags: 2, cached_tagged_user_names: ["Daniel Marty", "Marcamus Prime"]>] 

Nota l'attributo: cached_user_tag_list che include l'indirizzo di posta elettronica: danny@test.com.

Eppure, quando faccio le seguenti ricerche questi sono i risultati che ottengo:

[185] pry(main)> Node.node_search("dann") 
    Node Load (11.3ms) SELECT "nodes".*, ((ts_rank((to_tsvector('english', coalesce("nodes"."name"::text, '')) || to_tsvector('english', coalesce("nodes"."user_id"::text, '')) || to_tsvector('english', coalesce("nodes"."circa"::text, '')) || to_tsvector('english', coalesce("nodes"."cached_tagged_user_names"::text, '')) || to_tsvector('english', coalesce("nodes"."cached_user_tag_list"::text, '')) || to_tsvector('english', coalesce(pg_search_121ea89914a721445aee70.pg_search_344e3c62d13849726da22e::text, '')) || to_tsvector('english', coalesce(pg_search_4aab10cdca183dac25f479.pg_search_acfcdbc0b3d3a65f40eab7::text, '')) || to_tsvector('english', coalesce(pg_search_4aab10cdca183dac25f479.pg_search_eeb842708b24d4f7fcf549::text, '')) || to_tsvector('english', coalesce(pg_search_4aab10cdca183dac25f479.pg_search_cb8eb1b84bf18ee1412ffd::text, '')) || to_tsvector('english', coalesce(pg_search_b1bc4c0f44e7f4799d8caf.pg_search_9474fb5b090e75ade5136f::text, '')) || to_tsvector('english', coalesce(pg_search_93dd21271636bd02b16bc3.pg_search_484f77386a5aecc6e01094::text, ''))), (to_tsquery('english', ''' ' || 'dann' || ' ''' || ':*')), 0))) AS pg_search_rank FROM "nodes" LEFT OUTER JOIN (SELECT "nodes"."id" AS id, string_agg("comments"."message"::text, ' ') AS pg_search_344e3c62d13849726da22e FROM "nodes" INNER JOIN "comments" ON "comments"."node_id" = "nodes"."id" GROUP BY "nodes"."id") pg_search_121ea89914a721445aee70 ON pg_search_121ea89914a721445aee70.id = "nodes"."id" LEFT OUTER JOIN (SELECT "nodes"."id" AS id, string_agg("users"."first_name"::text, ' ') AS pg_search_acfcdbc0b3d3a65f40eab7, string_agg("users"."last_name"::text, ' ') AS pg_search_eeb842708b24d4f7fcf549, string_agg("users"."email"::text, ' ') AS pg_search_cb8eb1b84bf18ee1412ffd FROM "nodes" INNER JOIN "users" ON "users"."id" = "nodes"."user_id" GROUP BY "nodes"."id") pg_search_4aab10cdca183dac25f479 ON pg_search_4aab10cdca183dac25f479.id = "nodes"."id" LEFT OUTER JOIN (SELECT "nodes"."id" AS id, string_agg("memberships"."relation"::text, ' ') AS pg_search_9474fb5b090e75ade5136f FROM "nodes" INNER JOIN "family_trees" ON "family_trees"."id" = "nodes"."family_tree_id" INNER JOIN "memberships" ON "memberships"."family_tree_id" = "family_trees"."id" GROUP BY "nodes"."id") pg_search_b1bc4c0f44e7f4799d8caf ON pg_search_b1bc4c0f44e7f4799d8caf.id = "nodes"."id" LEFT OUTER JOIN (SELECT "nodes"."id" AS id, string_agg("tags"."name"::text, ' ') AS pg_search_484f77386a5aecc6e01094 FROM "nodes" INNER JOIN "taggings" ON "taggings"."taggable_id" = "nodes"."id" AND "taggings"."taggable_type" = 'Node' AND "taggings"."context" = 'user_tags' INNER JOIN "tags" ON "tags"."id" = "taggings"."tag_id" GROUP BY "nodes"."id") pg_search_93dd21271636bd02b16bc3 ON pg_search_93dd21271636bd02b16bc3.id = "nodes"."id" WHERE (((to_tsvector('english', coalesce("nodes"."name"::text, '')) || to_tsvector('english', coalesce("nodes"."user_id"::text, '')) || to_tsvector('english', coalesce("nodes"."circa"::text, '')) || to_tsvector('english', coalesce("nodes"."cached_tagged_user_names"::text, '')) || to_tsvector('english', coalesce("nodes"."cached_user_tag_list"::text, '')) || to_tsvector('english', coalesce(pg_search_121ea89914a721445aee70.pg_search_344e3c62d13849726da22e::text, '')) || to_tsvector('english', coalesce(pg_search_4aab10cdca183dac25f479.pg_search_acfcdbc0b3d3a65f40eab7::text, '')) || to_tsvector('english', coalesce(pg_search_4aab10cdca183dac25f479.pg_search_eeb842708b24d4f7fcf549::text, '')) || to_tsvector('english', coalesce(pg_search_4aab10cdca183dac25f479.pg_search_cb8eb1b84bf18ee1412ffd::text, '')) || to_tsvector('english', coalesce(pg_search_b1bc4c0f44e7f4799d8caf.pg_search_9474fb5b090e75ade5136f::text, '')) || to_tsvector('english', coalesce(pg_search_93dd21271636bd02b16bc3.pg_search_484f77386a5aecc6e01094::text, ''))) @@ (to_tsquery('english', ''' ' || 'dann' || ' ''' || ':*')))) ORDER BY pg_search_rank DESC, "nodes"."id" ASC 
=> [#<Node id: 85, name: "House Fire 2", family_tree_id: 57, user_id: 57, media_id: 228, media_type: "Video", created_at: "2015-05-15 00:20:26", updated_at: "2015-06-08 22:25:49", circa: nil, is_comment: nil, cached_votes_total: 0, cached_votes_score: 0, cached_votes_up: 0, cached_votes_down: 0, cached_weighted_score: 0, cached_weighted_total: 0, cached_weighted_average: 0.0, cached_user_tag_list: "danny@test.com, abc@test.com", cached_num_user_tags: 2, cached_tagged_user_names: ["Daniel Marty", "Marcamus Prime"]>] 
[186] pry(main)> Node.node_search("dan") 
    Node Load (4.2ms) SELECT "nodes".*, ((ts_rank((to_tsvector('english', coalesce("nodes"."name"::text, '')) || to_tsvector('english', coalesce("nodes"."user_id"::text, '')) || to_tsvector('english', coalesce("nodes"."circa"::text, '')) || to_tsvector('english', coalesce("nodes"."cached_tagged_user_names"::text, '')) || to_tsvector('english', coalesce("nodes"."cached_user_tag_list"::text, '')) || to_tsvector('english', coalesce(pg_search_121ea89914a721445aee70.pg_search_344e3c62d13849726da22e::text, '')) || to_tsvector('english', coalesce(pg_search_4aab10cdca183dac25f479.pg_search_acfcdbc0b3d3a65f40eab7::text, '')) || to_tsvector('english', coalesce(pg_search_4aab10cdca183dac25f479.pg_search_eeb842708b24d4f7fcf549::text, '')) || to_tsvector('english', coalesce(pg_search_4aab10cdca183dac25f479.pg_search_cb8eb1b84bf18ee1412ffd::text, '')) || to_tsvector('english', coalesce(pg_search_b1bc4c0f44e7f4799d8caf.pg_search_9474fb5b090e75ade5136f::text, '')) || to_tsvector('english', coalesce(pg_search_93dd21271636bd02b16bc3.pg_search_484f77386a5aecc6e01094::text, ''))), (to_tsquery('english', ''' ' || 'dan' || ' ''' || ':*')), 0))) AS pg_search_rank FROM "nodes" LEFT OUTER JOIN (SELECT "nodes"."id" AS id, string_agg("comments"."message"::text, ' ') AS pg_search_344e3c62d13849726da22e FROM "nodes" INNER JOIN "comments" ON "comments"."node_id" = "nodes"."id" GROUP BY "nodes"."id") pg_search_121ea89914a721445aee70 ON pg_search_121ea89914a721445aee70.id = "nodes"."id" LEFT OUTER JOIN (SELECT "nodes"."id" AS id, string_agg("users"."first_name"::text, ' ') AS pg_search_acfcdbc0b3d3a65f40eab7, string_agg("users"."last_name"::text, ' ') AS pg_search_eeb842708b24d4f7fcf549, string_agg("users"."email"::text, ' ') AS pg_search_cb8eb1b84bf18ee1412ffd FROM "nodes" INNER JOIN "users" ON "users"."id" = "nodes"."user_id" GROUP BY "nodes"."id") pg_search_4aab10cdca183dac25f479 ON pg_search_4aab10cdca183dac25f479.id = "nodes"."id" LEFT OUTER JOIN (SELECT "nodes"."id" AS id, string_agg("memberships"."relation"::text, ' ') AS pg_search_9474fb5b090e75ade5136f FROM "nodes" INNER JOIN "family_trees" ON "family_trees"."id" = "nodes"."family_tree_id" INNER JOIN "memberships" ON "memberships"."family_tree_id" = "family_trees"."id" GROUP BY "nodes"."id") pg_search_b1bc4c0f44e7f4799d8caf ON pg_search_b1bc4c0f44e7f4799d8caf.id = "nodes"."id" LEFT OUTER JOIN (SELECT "nodes"."id" AS id, string_agg("tags"."name"::text, ' ') AS pg_search_484f77386a5aecc6e01094 FROM "nodes" INNER JOIN "taggings" ON "taggings"."taggable_id" = "nodes"."id" AND "taggings"."taggable_type" = 'Node' AND "taggings"."context" = 'user_tags' INNER JOIN "tags" ON "tags"."id" = "taggings"."tag_id" GROUP BY "nodes"."id") pg_search_93dd21271636bd02b16bc3 ON pg_search_93dd21271636bd02b16bc3.id = "nodes"."id" WHERE (((to_tsvector('english', coalesce("nodes"."name"::text, '')) || to_tsvector('english', coalesce("nodes"."user_id"::text, '')) || to_tsvector('english', coalesce("nodes"."circa"::text, '')) || to_tsvector('english', coalesce("nodes"."cached_tagged_user_names"::text, '')) || to_tsvector('english', coalesce("nodes"."cached_user_tag_list"::text, '')) || to_tsvector('english', coalesce(pg_search_121ea89914a721445aee70.pg_search_344e3c62d13849726da22e::text, '')) || to_tsvector('english', coalesce(pg_search_4aab10cdca183dac25f479.pg_search_acfcdbc0b3d3a65f40eab7::text, '')) || to_tsvector('english', coalesce(pg_search_4aab10cdca183dac25f479.pg_search_eeb842708b24d4f7fcf549::text, '')) || to_tsvector('english', coalesce(pg_search_4aab10cdca183dac25f479.pg_search_cb8eb1b84bf18ee1412ffd::text, '')) || to_tsvector('english', coalesce(pg_search_b1bc4c0f44e7f4799d8caf.pg_search_9474fb5b090e75ade5136f::text, '')) || to_tsvector('english', coalesce(pg_search_93dd21271636bd02b16bc3.pg_search_484f77386a5aecc6e01094::text, ''))) @@ (to_tsquery('english', ''' ' || 'dan' || ' ''' || ':*')))) ORDER BY pg_search_rank DESC, "nodes"."id" ASC 
=> [#<Node id: 85, name: "House Fire 2", family_tree_id: 57, user_id: 57, media_id: 228, media_type: "Video", created_at: "2015-05-15 00:20:26", updated_at: "2015-06-08 22:25:49", circa: nil, is_comment: nil, cached_votes_total: 0, cached_votes_score: 0, cached_votes_up: 0, cached_votes_down: 0, cached_weighted_score: 0, cached_weighted_total: 0, cached_weighted_average: 0.0, cached_user_tag_list: "danny@test.com, abc@test.com", cached_num_user_tags: 2, cached_tagged_user_names: ["Daniel Marty", "Marcamus Prime"]>] 
[187] pry(main)> Node.node_search("danny") 
    Node Load (2.8ms) SELECT "nodes".*, ((ts_rank((to_tsvector('english', coalesce("nodes"."name"::text, '')) || to_tsvector('english', coalesce("nodes"."user_id"::text, '')) || to_tsvector('english', coalesce("nodes"."circa"::text, '')) || to_tsvector('english', coalesce("nodes"."cached_tagged_user_names"::text, '')) || to_tsvector('english', coalesce("nodes"."cached_user_tag_list"::text, '')) || to_tsvector('english', coalesce(pg_search_121ea89914a721445aee70.pg_search_344e3c62d13849726da22e::text, '')) || to_tsvector('english', coalesce(pg_search_4aab10cdca183dac25f479.pg_search_acfcdbc0b3d3a65f40eab7::text, '')) || to_tsvector('english', coalesce(pg_search_4aab10cdca183dac25f479.pg_search_eeb842708b24d4f7fcf549::text, '')) || to_tsvector('english', coalesce(pg_search_4aab10cdca183dac25f479.pg_search_cb8eb1b84bf18ee1412ffd::text, '')) || to_tsvector('english', coalesce(pg_search_b1bc4c0f44e7f4799d8caf.pg_search_9474fb5b090e75ade5136f::text, '')) || to_tsvector('english', coalesce(pg_search_93dd21271636bd02b16bc3.pg_search_484f77386a5aecc6e01094::text, ''))), (to_tsquery('english', ''' ' || 'danny' || ' ''' || ':*')), 0))) AS pg_search_rank FROM "nodes" LEFT OUTER JOIN (SELECT "nodes"."id" AS id, string_agg("comments"."message"::text, ' ') AS pg_search_344e3c62d13849726da22e FROM "nodes" INNER JOIN "comments" ON "comments"."node_id" = "nodes"."id" GROUP BY "nodes"."id") pg_search_121ea89914a721445aee70 ON pg_search_121ea89914a721445aee70.id = "nodes"."id" LEFT OUTER JOIN (SELECT "nodes"."id" AS id, string_agg("users"."first_name"::text, ' ') AS pg_search_acfcdbc0b3d3a65f40eab7, string_agg("users"."last_name"::text, ' ') AS pg_search_eeb842708b24d4f7fcf549, string_agg("users"."email"::text, ' ') AS pg_search_cb8eb1b84bf18ee1412ffd FROM "nodes" INNER JOIN "users" ON "users"."id" = "nodes"."user_id" GROUP BY "nodes"."id") pg_search_4aab10cdca183dac25f479 ON pg_search_4aab10cdca183dac25f479.id = "nodes"."id" LEFT OUTER JOIN (SELECT "nodes"."id" AS id, string_agg("memberships"."relation"::text, ' ') AS pg_search_9474fb5b090e75ade5136f FROM "nodes" INNER JOIN "family_trees" ON "family_trees"."id" = "nodes"."family_tree_id" INNER JOIN "memberships" ON "memberships"."family_tree_id" = "family_trees"."id" GROUP BY "nodes"."id") pg_search_b1bc4c0f44e7f4799d8caf ON pg_search_b1bc4c0f44e7f4799d8caf.id = "nodes"."id" LEFT OUTER JOIN (SELECT "nodes"."id" AS id, string_agg("tags"."name"::text, ' ') AS pg_search_484f77386a5aecc6e01094 FROM "nodes" INNER JOIN "taggings" ON "taggings"."taggable_id" = "nodes"."id" AND "taggings"."taggable_type" = 'Node' AND "taggings"."context" = 'user_tags' INNER JOIN "tags" ON "tags"."id" = "taggings"."tag_id" GROUP BY "nodes"."id") pg_search_93dd21271636bd02b16bc3 ON pg_search_93dd21271636bd02b16bc3.id = "nodes"."id" WHERE (((to_tsvector('english', coalesce("nodes"."name"::text, '')) || to_tsvector('english', coalesce("nodes"."user_id"::text, '')) || to_tsvector('english', coalesce("nodes"."circa"::text, '')) || to_tsvector('english', coalesce("nodes"."cached_tagged_user_names"::text, '')) || to_tsvector('english', coalesce("nodes"."cached_user_tag_list"::text, '')) || to_tsvector('english', coalesce(pg_search_121ea89914a721445aee70.pg_search_344e3c62d13849726da22e::text, '')) || to_tsvector('english', coalesce(pg_search_4aab10cdca183dac25f479.pg_search_acfcdbc0b3d3a65f40eab7::text, '')) || to_tsvector('english', coalesce(pg_search_4aab10cdca183dac25f479.pg_search_eeb842708b24d4f7fcf549::text, '')) || to_tsvector('english', coalesce(pg_search_4aab10cdca183dac25f479.pg_search_cb8eb1b84bf18ee1412ffd::text, '')) || to_tsvector('english', coalesce(pg_search_b1bc4c0f44e7f4799d8caf.pg_search_9474fb5b090e75ade5136f::text, '')) || to_tsvector('english', coalesce(pg_search_93dd21271636bd02b16bc3.pg_search_484f77386a5aecc6e01094::text, ''))) @@ (to_tsquery('english', ''' ' || 'danny' || ' ''' || ':*')))) ORDER BY pg_search_rank DESC, "nodes"."id" ASC 
=> [] 

noti che restituisce un risultato vuoto sulla query danny, tuttavia restituisce i record giusti sulla query dan e dann .

Dato che la stringa è danny@test.com, non è danny un prefisso di quella stringa?

Si noti che per l'indirizzo di posta elettronica abc@test.com, la ricerca di abc restituisce i risultati corretti come si vede qui sotto:

[188] pry(main)> Node.node_search("abc") 
    Node Load (6.9ms) SELECT "nodes".*, ((ts_rank((to_tsvector('english', coalesce("nodes"."name"::text, '')) || to_tsvector('english', coalesce("nodes"."user_id"::text, '')) || to_tsvector('english', coalesce("nodes"."circa"::text, '')) || to_tsvector('english', coalesce("nodes"."cached_tagged_user_names"::text, '')) || to_tsvector('english', coalesce("nodes"."cached_user_tag_list"::text, '')) || to_tsvector('english', coalesce(pg_search_121ea89914a721445aee70.pg_search_344e3c62d13849726da22e::text, '')) || to_tsvector('english', coalesce(pg_search_4aab10cdca183dac25f479.pg_search_acfcdbc0b3d3a65f40eab7::text, '')) || to_tsvector('english', coalesce(pg_search_4aab10cdca183dac25f479.pg_search_eeb842708b24d4f7fcf549::text, '')) || to_tsvector('english', coalesce(pg_search_4aab10cdca183dac25f479.pg_search_cb8eb1b84bf18ee1412ffd::text, '')) || to_tsvector('english', coalesce(pg_search_b1bc4c0f44e7f4799d8caf.pg_search_9474fb5b090e75ade5136f::text, '')) || to_tsvector('english', coalesce(pg_search_93dd21271636bd02b16bc3.pg_search_484f77386a5aecc6e01094::text, ''))), (to_tsquery('english', ''' ' || 'abc' || ' ''' || ':*')), 0))) AS pg_search_rank FROM "nodes" LEFT OUTER JOIN (SELECT "nodes"."id" AS id, string_agg("comments"."message"::text, ' ') AS pg_search_344e3c62d13849726da22e FROM "nodes" INNER JOIN "comments" ON "comments"."node_id" = "nodes"."id" GROUP BY "nodes"."id") pg_search_121ea89914a721445aee70 ON pg_search_121ea89914a721445aee70.id = "nodes"."id" LEFT OUTER JOIN (SELECT "nodes"."id" AS id, string_agg("users"."first_name"::text, ' ') AS pg_search_acfcdbc0b3d3a65f40eab7, string_agg("users"."last_name"::text, ' ') AS pg_search_eeb842708b24d4f7fcf549, string_agg("users"."email"::text, ' ') AS pg_search_cb8eb1b84bf18ee1412ffd FROM "nodes" INNER JOIN "users" ON "users"."id" = "nodes"."user_id" GROUP BY "nodes"."id") pg_search_4aab10cdca183dac25f479 ON pg_search_4aab10cdca183dac25f479.id = "nodes"."id" LEFT OUTER JOIN (SELECT "nodes"."id" AS id, string_agg("memberships"."relation"::text, ' ') AS pg_search_9474fb5b090e75ade5136f FROM "nodes" INNER JOIN "family_trees" ON "family_trees"."id" = "nodes"."family_tree_id" INNER JOIN "memberships" ON "memberships"."family_tree_id" = "family_trees"."id" GROUP BY "nodes"."id") pg_search_b1bc4c0f44e7f4799d8caf ON pg_search_b1bc4c0f44e7f4799d8caf.id = "nodes"."id" LEFT OUTER JOIN (SELECT "nodes"."id" AS id, string_agg("tags"."name"::text, ' ') AS pg_search_484f77386a5aecc6e01094 FROM "nodes" INNER JOIN "taggings" ON "taggings"."taggable_id" = "nodes"."id" AND "taggings"."taggable_type" = 'Node' AND "taggings"."context" = 'user_tags' INNER JOIN "tags" ON "tags"."id" = "taggings"."tag_id" GROUP BY "nodes"."id") pg_search_93dd21271636bd02b16bc3 ON pg_search_93dd21271636bd02b16bc3.id = "nodes"."id" WHERE (((to_tsvector('english', coalesce("nodes"."name"::text, '')) || to_tsvector('english', coalesce("nodes"."user_id"::text, '')) || to_tsvector('english', coalesce("nodes"."circa"::text, '')) || to_tsvector('english', coalesce("nodes"."cached_tagged_user_names"::text, '')) || to_tsvector('english', coalesce("nodes"."cached_user_tag_list"::text, '')) || to_tsvector('english', coalesce(pg_search_121ea89914a721445aee70.pg_search_344e3c62d13849726da22e::text, '')) || to_tsvector('english', coalesce(pg_search_4aab10cdca183dac25f479.pg_search_acfcdbc0b3d3a65f40eab7::text, '')) || to_tsvector('english', coalesce(pg_search_4aab10cdca183dac25f479.pg_search_eeb842708b24d4f7fcf549::text, '')) || to_tsvector('english', coalesce(pg_search_4aab10cdca183dac25f479.pg_search_cb8eb1b84bf18ee1412ffd::text, '')) || to_tsvector('english', coalesce(pg_search_b1bc4c0f44e7f4799d8caf.pg_search_9474fb5b090e75ade5136f::text, '')) || to_tsvector('english', coalesce(pg_search_93dd21271636bd02b16bc3.pg_search_484f77386a5aecc6e01094::text, ''))) @@ (to_tsquery('english', ''' ' || 'abc' || ' ''' || ':*')))) ORDER BY pg_search_rank DESC, "nodes"."id" ASC 
=> [#<Node id: 85, name: "House Fire 2", family_tree_id: 57, user_id: 57, media_id: 228, media_type: "Video", created_at: "2015-05-15 00:20:26", updated_at: "2015-06-08 22:25:49", circa: nil, is_comment: nil, cached_votes_total: 0, cached_votes_score: 0, cached_votes_up: 0, cached_votes_down: 0, cached_weighted_score: 0, cached_weighted_total: 0, cached_weighted_average: 0.0, cached_user_tag_list: "danny@test.com, abc@test.com", cached_num_user_tags: 2, cached_tagged_user_names: ["Daniel Marty", "Marcamus Prime"]>, 
#<Node id: 86, name: "10PP Form Video", family_tree_id: 57, user_id: 57, media_id: 229, media_type: "Video", created_at: "2015-05-15 01:26:28", updated_at: "2015-06-05 21:10:09", circa: nil, is_comment: nil, cached_votes_total: 1, cached_votes_score: 1, cached_votes_up: 1, cached_votes_down: 0, cached_weighted_score: 1, cached_weighted_total: 1, cached_weighted_average: 0.0, cached_user_tag_list: "gerry@test.com", cached_num_user_tags: 1, cached_tagged_user_names: ["Gerry Atrick"]>] 

quello che potrebbe essere la causa di questo?

Modifica 1

Per rendere le cose più strane, ho pensato che fosse la @ che potrebbe essere gettando via la ricerca di prefisso, quindi ho provato semplicemente cambiando l'attributo di cached_user_tag_listdanny@test.com-dannyk@test.com. Quindi ho cercato dannyk e ho restituito il risultato corretto, ma quando ho cercato danny restituisce ancora []. Non ho idea del perché.

Answer 1

È possibile attivare :trigram search e specificare la soglia. Corrisponde a sotto-stringhe arbitrarie che appaiono ovunque nel testo ricercabile. Il tuo codice finale sarebbe simile a questo.

pg_search_scope :node_search, against: [:name, :user_id, :circa, :cached_tagged_user_names, :cached_user_tag_list], 
    using: { tsearch: { any_word: true, dictionary: :english, prefix: true}, :trigram => { :threshold => 0.1 } }, 
     :associated_against => { 
      comments: [:message], 
      user: [:first_name, :last_name, :email], 
      memberships: [:relation], 
      user_tags: [:name] 
     }