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如何我可以索引这个查询免费文本搜索

2012-08-13 38 views
3

嗨亲爱的Postgres的用户，如何我可以索引这个查询免费文本搜索

短的故事，我有相关的国家（每个地址都有一个状态）地址表。我将运行以下查询进行搜索：

SELECT "addresses".*, (ts_rank((to_tsvector('simple', coalesce("addresses"."name"::text, '')) || to_tsvector('simple', coalesce(pg_search_85240c410826a2b0e0f0e5.pg_search_442c4ad3183a256248ef8d::text, ''))), (to_tsquery('simple', ''' ' || 'test' || ' ''' || ':*')), 0)) AS pg_search_rank 
FROM "addresses" 
LEFT OUTER JOIN (SELECT "addresses"."id" AS id, string_agg("states"."name"::text, ' ') AS pg_search_442c4ad3183a256248ef8d 
      FROM "addresses" INNER JOIN "states" ON "states"."id" = "addresses"."state_id" GROUP BY "addresses"."id") pg_search_85240c410826a2b0e0f0e5 ON pg_search_85240c410826a2b0e0f0e5.id = "addresses"."id" 
      WHERE (((to_tsvector('simple', coalesce("addresses"."name"::text, '')) || to_tsvector('simple', coalesce(pg_search_85240c410826a2b0e0f0e5.pg_search_442c4ad3183a256248ef8d::text, ''))) @@ (to_tsquery('simple', ''' ' || 'test' || ' ''' || ':*')))) AND (company_id = 2142) 
      ORDER BY pg_search_rank DESC, "addresses"."id" ASC

直向前，对吗？这在一台好的机器和8581个地址上需要大约1.226ms。我需要改善这一点，所以我创建这个索引2

CREATE INDEX index_addresses_search_by_name ON addresses USING gin(to_tsvector('simple', COALESCE((public.addresses.name)::text, ''))) 
CREATE INDEX index_state_search_by_name ON states USING gin(to_tsvector('simple', COALESCE((public.states.name)::text, '')))

这将有助于创建上解决了指数，并在美国一个指标，但它并不:(查询速度慢和以前一样解释显示未使用的指标

请提供一个建议，

编辑：

这里是解释分析会显示：

"Sort (cost=11.39..11.40 rows=1 width=4824) (actual time=0.947..0.947 rows=0 loops=1)" 
" Sort Key: (ts_rank((to_tsvector('simple'::regconfig, COALESCE((public.addresses.name)::text, ''::text)) || to_tsvector('simple'::regconfig, COALESCE((string_agg((states.name)::text, ' '::text)), ''::text))), '''test'':*'::tsquery, 0)), public.addresses.id" 
" Sort Method: quicksort Memory: 17kB" 
" -> Nested Loop Left Join (cost=6.19..11.38 rows=1 width=4824) (actual time=0.905..0.905 rows=0 loops=1)" 
"  Join Filter: (public.addresses.id = public.addresses.id)" 
"  Filter: ((to_tsvector('simple'::regconfig, COALESCE((public.addresses.name)::text, ''::text)) || to_tsvector('simple'::regconfig, COALESCE((string_agg((states.name)::text, ' '::text)), ''::text))) @@ '''test'':*'::tsquery)" 
"  -> Seq Scan on addresses (cost=0.00..5.14 rows=1 width=4792) (actual time=0.904..0.904 rows=0 loops=1)" 
"    Filter: (company_id = 2142)" 
"  -> HashAggregate (cost=6.19..6.20 rows=1 width=520) (never executed)" 
"    -> Hash Join (cost=1.02..6.18 rows=1 width=520) (never executed)" 
"     Hash Cond: (public.addresses.state_id = states.id)" 
"     -> Seq Scan on addresses (cost=0.00..5.11 rows=11 width=8) (never executed)" 
"     -> Hash (cost=1.01..1.01 rows=1 width=520) (never executed)" 
"       -> Seq Scan on states (cost=0.00..1.01 rows=1 width=520) (never executed)" 
"Total runtime: 1.226 ms"

EDIT2

地址DDL

-- 
-- PostgreSQL database dump 
-- 

SET statement_timeout = 0; 
SET client_encoding = 'UTF8'; 
SET standard_conforming_strings = on; 
SET check_function_bodies = false; 
SET client_min_messages = warning; 

SET search_path = public, pg_catalog; 

SET default_tablespace = ''; 

SET default_with_oids = false; 

-- 
-- Name: addresses; Type: TABLE; Schema: public; Owner: trucking; Tablespace: 
-- 

CREATE TABLE addresses (
    id integer NOT NULL, 
    name character varying(255), 
    street character varying(255), 
    city character varying(255), 
    zip_code character varying(255), 
    primary_phone character varying(255), 
    alternate_phone character varying(255), 
    fax character varying(255), 
    email character varying(255), 
    contact character varying(255), 
    company_id integer DEFAULT 0 NOT NULL, 
    motor_carrier_number character varying(12), 
    state_id integer, 
    created_at timestamp without time zone, 
    updated_at timestamp without time zone, 
    alternate_phone2 character varying(12), 
    insurance_expires_on date, 
    notes text 
); 


ALTER TABLE public.addresses OWNER TO trucking; 

-- 
-- Name: addresses_id_seq; Type: SEQUENCE; Schema: public; Owner: trucking 
-- 

CREATE SEQUENCE addresses_id_seq 
    START WITH 1 
    INCREMENT BY 1 
    NO MINVALUE 
    NO MAXVALUE 
    CACHE 1; 


ALTER TABLE public.addresses_id_seq OWNER TO trucking; 

-- 
-- Name: addresses_id_seq; Type: SEQUENCE OWNED BY; Schema: public; Owner: trucking 
-- 

ALTER SEQUENCE addresses_id_seq OWNED BY addresses.id; 


-- 
-- Name: id; Type: DEFAULT; Schema: public; Owner: trucking 
-- 

ALTER TABLE ONLY addresses ALTER COLUMN id SET DEFAULT nextval('addresses_id_seq'::regclass); 


-- 
-- Name: addresses_pkey; Type: CONSTRAINT; Schema: public; Owner: trucking; Tablespace: 
-- 

ALTER TABLE ONLY addresses 
    ADD CONSTRAINT addresses_pkey PRIMARY KEY (id); 


-- 
-- Name: index_addresses_on_company_id; Type: INDEX; Schema: public; Owner: trucking; Tablespace: 
-- 

CREATE INDEX index_addresses_on_company_id ON addresses USING btree (company_id); 


-- 
-- Name: index_addresses_on_state_id; Type: INDEX; Schema: public; Owner: trucking; Tablespace: 
-- 

CREATE INDEX index_addresses_on_state_id ON addresses USING btree (state_id); 


-- 
-- Name: index_addresses_search_by_city; Type: INDEX; Schema: public; Owner: trucking; Tablespace: 
-- 

CREATE INDEX index_addresses_search_by_city ON addresses USING gin (to_tsvector('simple'::regconfig, COALESCE((city)::text, ''::text))); 


-- 
-- Name: index_addresses_search_by_email; Type: INDEX; Schema: public; Owner: trucking; Tablespace: 
-- 

CREATE INDEX index_addresses_search_by_email ON addresses USING gin (to_tsvector('simple'::regconfig, COALESCE((email)::text, ''::text))); 


-- 
-- Name: index_addresses_search_by_name; Type: INDEX; Schema: public; Owner: trucking; Tablespace: 
-- 

CREATE INDEX index_addresses_search_by_name ON addresses USING gin (to_tsvector('simple'::regconfig, COALESCE((name)::text, ''::text))); 


-- 
-- Name: index_addresses_search_by_street; Type: INDEX; Schema: public; Owner: trucking; Tablespace: 
-- 

CREATE INDEX index_addresses_search_by_street ON addresses USING gin (to_tsvector('simple'::regconfig, COALESCE((street)::text, ''::text))); 


-- 
-- PostgreSQL database dump complete 
--

美国DDL

-- 
-- PostgreSQL database dump 
-- 

SET statement_timeout = 0; 
SET client_encoding = 'UTF8'; 
SET standard_conforming_strings = on; 
SET check_function_bodies = false; 
SET client_min_messages = warning; 

SET search_path = public, pg_catalog; 

SET default_tablespace = ''; 

SET default_with_oids = false; 

-- 
-- Name: states; Type: TABLE; Schema: public; Owner: trucking; Tablespace: 
-- 

CREATE TABLE states (
    id integer NOT NULL, 
    name character varying(255) NOT NULL, 
    abbrev character varying(255) NOT NULL, 
    country character varying(255) 
); 


ALTER TABLE public.states OWNER TO trucking; 

-- 
-- Name: states_id_seq; Type: SEQUENCE; Schema: public; Owner: trucking 
-- 

CREATE SEQUENCE states_id_seq 
    START WITH 1 
    INCREMENT BY 1 
    NO MINVALUE 
    NO MAXVALUE 
    CACHE 1; 


ALTER TABLE public.states_id_seq OWNER TO trucking; 

-- 
-- Name: states_id_seq; Type: SEQUENCE OWNED BY; Schema: public; Owner: trucking 
-- 

ALTER SEQUENCE states_id_seq OWNED BY states.id; 


-- 
-- Name: id; Type: DEFAULT; Schema: public; Owner: trucking 
-- 

ALTER TABLE ONLY states ALTER COLUMN id SET DEFAULT nextval('states_id_seq'::regclass); 


-- 
-- Name: states_pkey; Type: CONSTRAINT; Schema: public; Owner: trucking; Tablespace: 
-- 

ALTER TABLE ONLY states 
    ADD CONSTRAINT states_pkey PRIMARY KEY (id); 


-- 
-- Name: index_states_search_by_abbrev; Type: INDEX; Schema: public; Owner: trucking; Tablespace: 
-- 

CREATE INDEX index_states_search_by_abbrev ON states USING gin (to_tsvector('simple'::regconfig, COALESCE((abbrev)::text, ''::text))); 


-- 
-- Name: index_states_search_by_name; Type: INDEX; Schema: public; Owner: trucking; Tablespace: 
-- 

CREATE INDEX index_states_search_by_name ON states USING gin (to_tsvector('simple'::regconfig, COALESCE((name)::text, ''::text))); 


-- 
-- PostgreSQL database dump complete 
--

最佳改写到目前为止

SELECT consolidated_address.id, (ts_rank((to_tsvector('simple', coalesce(consolidated_address.name::text, '')) || to_tsvector('simple', coalesce(consolidated_address.state_name::text, ''))), (to_tsquery('simple', ''' ' || 'Gallaway' || ' ''' || ':*')), 0)) AS pg_search_rank 
FROM (
SELECT "addresses".id, 
    "addresses".name, 
    string_agg("states".name::text, ' ') as state_name 
    FROM addresses 
    LEFT OUTER JOIN "states" 
    ON "states".id = "addresses".state_id 
    GROUP BY "addresses".id) consolidated_address 
WHERE 
    (((to_tsvector('simple', coalesce(consolidated_address.name::text, '')) || to_tsvector('simple', coalesce(consolidated_address.state_name::text, ''))) @@ (to_tsquery('simple', ''' ' || 'Gallaway' || ' ''' || ':*'))))

这是一个快一点，但还是做ES没有用任何指标

的谢谢，

来源

2012-08-13 Calin

+0

对于将来的问题，请确保显示您的Pg版本，并且对于缓慢的查询问题“EXPLAIN ANALYZE SELECT ....的输出....您的查询....”。查看https://wiki.postgresql.org/wiki/Slow_Query_Questions – 2012-08-14 00:17:41

+0

编辑了这个问题，谢谢@CraigRinger – Calin 2012-08-14 12:14:59

+0

你有索引创建后分析你的表吗？我们可以看到涉及的表格和约束的DDL吗？ – vyegorov 2012-08-14 12:44:36

回答

0

这个查询慢是因为你是通过左外侧连接到联接的查询使用聚合整个地址表然后通过COMPANY_ID限制。地址表是否有company_id？尝试将where子句移到内部查询中以限制返回的记录数。

来源

2012-08-13 23:42:17 andycamp

+0

感谢您的答案，但这并不能解释为什么索引不使用 – Calin 2012-08-14 11:28:21

+0

顺便说一句，我会+1这个答案，如果你能请你重写与您的建议查询。 – Calin 2012-08-14 11:28:49

1

回答交叉张贴在https://github.com/Casecommons/pg_search/issues/51

从GitHub我产生这个查询pg_search红宝石宝石的作者。

呀，可惜我不知道的一种方式来获得：associated_against查询对索引工作，至少事物的方式正在实现。

这是因为：associated_against搜索所有关联记录的文本连接在一起，而不是在一个单独的记录上。例如，如果你加入了一个标签表，并且有3条记录（“foo”，“bar”和“baz”），那么你会希望搜索“foo baz”来找到它。更容易索引的解决方案只适用于“foo”或“baz”查询，但不适用于“foo baz”，因为如果您知道我的意思，则单个标签行中没有任何一个符合这两个条款。

不可能为多个记录建立索引（至少据我所知）。

也许我们可以在pg_search中选择一个选项来执行逐条记录搜索，它可以使用索引但不匹配记录。

来源

2012-08-14 17:48:50 nertzy

+0

我希望看到一个熟练的sql dude重写这个查询，如果有一种方法 – Calin 2012-08-14 19:09:34

+0

如果有办法做到这一点，让我知道，我会更新pg_search使用这种方式。 – nertzy 2012-09-09 22:40:04

1

我对你的解释分析输出的阅读是你的表太小而无法使用索引。 PostgreSQL上的顺序扫描相对便宜，因为表格被加载为物理文件，PostgreSQL可以利用操作系统预取等。

请记住，没有计划比从磁盘加载单个页面并按顺序扫描更快。使用索引只会增加开销。在顺序扫描上没有任何重要的时间，所以不用担心，直到你有真正的数据可以玩。

值得注意的是，在PostgreSQL上，在有数据之前优化查询是比解决方案更多问题的秘诀。我真诚的建议是等待分析查询，直到您有真实的数据返回。然后我们可以确定哪些索引会有帮助。

编辑：你说查询很慢。但该计划显示它在1ms内执行。你预计会花多少时间？

来源

2012-09-30 01:25:19

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