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Re: Full Text index is not using during OR operation

From: Oleg Bartunov <oleg(at)sai(dot)msu(dot)su>
To: AI Rumman <rummandba(at)gmail(dot)com>
Cc: pgsql-performance(at)postgresql(dot)org
Subject: Re: Full Text index is not using during OR operation
Date: 2010-11-29 12:37:54
Message-ID: Pine.LNX.4.64.1011291536130.12632@sn.sai.msu.ru (view raw or flat)
Thread:
Lists: pgsql-performance
What does replace(' Dhaka University of Bangladesh:*', ' ',':* & ') means ?
I see it produces something wrong for to_tsquery:

test=# select replace(' Dhaka University of Bangladesh:*', ' ',':* & ');
                       replace 
---------------------------------------------------
  :* & Dhaka:* & University:* & of:* & Bangladesh:*
(1 row)

Oleg

On Mon, 29 Nov 2010, AI Rumman wrote:

> explain
> SELECT crmentity.crmid, crmentity.setype, crmentity.modifiedtime,
> activity.subject,case when ( users.user_name not like '') then
> users.user_name else groups.groupname end as user_name, activity.date_start
> FROM crmentity INNER JOIN activity ON crmentity.crmid = activity.activityid
> and crmentity.deleted = 0
> LEFT JOIN activitygrouprelation ON activitygrouprelation.activityid =
> crmentity.crmid
> LEFT JOIN groups ON groups.groupname = activitygrouprelation.groupname
> LEFT join users ON crmentity.smownerid= users.id
> WHERE
> to_tsvector(' en', for_fts( activity.subject)) @@ to_tsquery(' en',
> replace(' Dhaka University of Bangladesh:*', ' ',':* & '))
> or
> to_tsvector(' en', for_fts( crmentity.description)) @@ to_tsquery(' en',
> replace(' Dhaka University of Bangladesh:*', ' ',':* & '))
> ORDER BY crmentity.modifiedtime DESC LIMIT 100
>
>  QUERY PLAN
>
> ------------------------------------------------------------------------------------------------------------------------------------------
> Limit (cost=112724.54..112724.54 rows=1 width=99)
>  -> Sort (cost=112724.54..112724.54 rows=1 width=99)
>  Sort Key: crmentity.modifiedtime
>  -> Nested Loop Left Join (cost=0.00..112724.53 rows=1 width=99)
>  -> Nested Loop Left Join (cost=0.00..112724.24 rows=1 width=82)
>  -> Nested Loop Left Join (cost=0.00..112723.96 rows=1 width=79)
>  -> Nested Loop (cost=0.00..112723.68 rows=1 width=56)
>  Join Filter: ((to_tsvector('en'::regconfig,
> regexp_replace((activity.subject)::text,
> '(&[^;]+;)|(<[^>]+>)|([\\s\\r\\n\\t]+)'::text, ''::text, 'gs'::text)) @@ '''
> Dhaka'':* & ''univers'':* & ''bangladesh'':*'::tsquery) OR
> (to_tsvector('en'::regconfig, regexp_replace(crmentity.description,
> '(&[^;]+;)|(<[^>]+>)|([\\s\\r\\n\\t]+)'::text, ' '::text, 'gs'::text)) @@
> ''' Dhaka'':* & ''univers'':* & ''bangladesh'':*'::tsquery))
>  -> Index Scan using activity_pkey on activity (cost=0.00..10223.89
> rows=343070 width=36)
>  -> Index Scan using crmentity_pkey on crmentity (cost=0.00..0.27 rows=1
> width=151)
>  Index Cond: (crmentity.crmid = activity.activityid)
>  Filter: (crmentity.deleted = 0)
>  -> Index Scan using activitygrouprelation_activityid_idx on
> activitygrouprelation (cost=0.00..0.27 rows=1 width=27)
>  Index Cond: (activitygrouprelation.activityid = crmentity.crmid)
>  -> Index Scan using groups_groupname_idx on groups (cost=0.00..0.27 rows=1
> width=26)
>  Index Cond: ((groups.groupname)::text =
> (activitygrouprelation.groupname)::text)
>  -> Index Scan using users_pkey on users (cost=0.00..0.27 rows=1 width=25)
>  Index Cond: (crmentity.smownerid = users.id)
>
>
> The above query are not using fts indexes, even hang the server.
>
> But,
>
>
> explain
> SELECT crmentity.crmid, crmentity.setype, crmentity.modifiedtime,
> activity.subject,case when ( users.user_name not like '') then
> users.user_name else groups.groupname end as user_name, activity.date_start
> FROM crmentity INNER JOIN activity ON crmentity.crmid = activity.activityid
> and crmentity.deleted = 0
> LEFT JOIN activitygrouprelation ON activitygrouprelation.activityid =
> crmentity.crmid
> LEFT JOIN groups ON groups.groupname = activitygrouprelation.groupname
> LEFT join users ON crmentity.smownerid= users.id
> WHERE
> to_tsvector(' en', for_fts( activity.subject)) @@ to_tsquery(' en',
> replace(' Dhaka University of Bangladesh:*', ' ',':* & '))
> ORDER BY crmentity.modifiedtime DESC LIMIT 100
>
> ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
>
> Limit (cost=1.46..1.47 rows=1 width=99) (actual time=0.824..0.824 rows=0
> loops=1)
>  -> Sort (cost=1.46..1.47 rows=1 width=99) (actual time=0.819..0.819 rows=0
> loops=1)
>  Sort Key: crmentity.modifiedtime
>  Sort Method: quicksort Memory: 17kB
>  -> Nested Loop Left Join (cost=0.27..1.45 rows=1 width=99) (actual
> time=0.752..0.752 rows=0 loops=1)
>  -> Nested Loop Left Join (cost=0.27..1.17 rows=1 width=82) (actual
> time=0.750..0.750 rows=0 loops=1)
>  -> Nested Loop Left Join (cost=0.27..0.88 rows=1 width=79) (actual
> time=0.748..0.748 rows=0 loops=1)
>  -> Nested Loop (cost=0.27..0.60 rows=1 width=56) (actual time=0.746..0.746
> rows=0 loops=1)
>  -> Bitmap Heap Scan on activity (cost=0.27..0.30 rows=1 width=36) (actual
> time=0.744..0.744 rows=0 loops=1)
>  Recheck Cond: (to_tsvector('en'::regconfig,
> regexp_replace((subject)::text,
> '(&[^;]+;)|(<[^>]+>)|([\\s\\r\\n\\t]+)'::text, ' '::text,
> 'gs'::text)) @@ ''' Dhaka'':* & ''univers'':* & ''bangladesh'':*'::tsquery)
>  -> Bitmap Index Scan on ftx_en_activity_subject (cost=0.00..0.27 rows=1
> width=0) (actual time=0.740..0.740 rows=0 loops=1)
>  Index Cond: (to_tsvector('en'::regconfig, regexp_replace((subject)::text,
> '(&[^;]+;)|(<[^>]+>)|([\\s\\r\\n\\t]+)'::text, ' '::te
> xt, 'gs'::text)) @@ ''' Dhaka'':* & ''univers'':* &
> ''bangladesh'':*'::tsquery)
>  -> Index Scan using crmentity_pkey on crmentity (cost=0.00..0.29 rows=1
> width=24) (never executed)
>  Index Cond: (crmentity.crmid = activity.activityid)
>  Filter: (crmentity.deleted = 0)
>  -> Index Scan using activitygrouprelation_activityid_idx on
> activitygrouprelation (cost=0.00..0.27 rows=1 width=27) (never executed)
>  Index Cond: (activitygrouprelation.activityid = crmentity.crmid)
>  -> Index Scan using groups_groupname_idx on groups (cost=0.00..0.27 rows=1
> width=26) (never executed)
>  Index Cond: ((groups.groupname)::text =
> (activitygrouprelation.groupname)::text)
>  -> Index Scan using users_pkey on users (cost=0.00..0.27 rows=1 width=25)
> (never executed)
>  Index Cond: (crmentity.smownerid = users.id)
> Total runtime: 1.188 ms
>
>
>
>
> explain
> SELECT crmentity.crmid, crmentity.setype, crmentity.modifiedtime,
> activity.subject,case when ( users.user_name not like '') then
> users.user_name else groups.groupname end as user_name, activity.date_start
> FROM crmentity INNER JOIN activity ON crmentity.crmid = activity.activityid
> and crmentity.deleted = 0
> LEFT JOIN activitygrouprelation ON activitygrouprelation.activityid =
> crmentity.crmid
> LEFT JOIN groups ON groups.groupname = activitygrouprelation.groupname
> LEFT join users ON crmentity.smownerid= users.id
> WHERE
> to_tsvector(' en', for_fts( crmentity.description)) @@ to_tsquery(' en',
> replace(' Dhaka University of Bangladesh:*', ' ',':* & '))
> ORDER BY crmentity.modifiedtime DESC LIMIT 100
>
>  QUERY PLAN
>
> ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
>
> Limit (cost=1.50..1.51 rows=1 width=99) (actual time=5.044..5.047 rows=1
> loops=1)
>  -> Sort (cost=1.50..1.51 rows=1 width=99) (actual time=5.041..5.042 rows=1
> loops=1)
>  Sort Key: crmentity.modifiedtime
>  Sort Method: quicksort Memory: 17kB
>  -> Nested Loop Left Join (cost=0.27..1.49 rows=1 width=99) (actual
> time=4.998..5.012 rows=1 loops=1)
>  -> Nested Loop Left Join (cost=0.27..1.19 rows=1 width=82) (actual
> time=4.952..4.961 rows=1 loops=1)
>  -> Nested Loop Left Join (cost=0.27..0.90 rows=1 width=79) (actual
> time=4.949..4.956 rows=1 loops=1)
>  -> Nested Loop (cost=0.27..0.60 rows=1 width=56) (actual time=4.943..4.948
> rows=1 loops=1)
>  -> Bitmap Heap Scan on crmentity (cost=0.27..0.30 rows=1 width=24) (actual
> time=4.727..4.799 rows=3 loops=1)
>  Recheck Cond: (to_tsvector('en'::regconfig, regexp_replace(description,
> '(&[^;]+;)|(<[^>]+>)|([\\s\\r\\n\\t]+)'::text, ' '::text, 'gs'
> ::text)) @@ ''' Dhaka'':* & ''univers'':* & ''bangladesh'':*'::tsquery)
>  Filter: (deleted = 0)
>  -> Bitmap Index Scan on ftx_en_crmentity_description (cost=0.00..0.27
> rows=1 width=0) (actual time=4.687..4.687 rows=3 loops=1)
>  Index Cond: (to_tsvector('en'::regconfig, regexp_replace(description,
> '(&[^;]+;)|(<[^>]+>)|([\\s\\r\\n\\t]+)'::text, ' '::text,
> 'gs'::text)) @@ ''' Dhaka'':* & ''univers'':* & ''bangladesh'':*'::tsquery)
>  -> Index Scan using activity_pkey on activity (cost=0.00..0.29 rows=1
> width=36) (actual time=0.043..0.043 rows=0 loops=3)
>  Index Cond: (activity.activityid = crmentity.crmid)
>  -> Index Scan using activitygrouprelation_activityid_idx on
> activitygrouprelation (cost=0.00..0.29 rows=1 width=27) (actual
> time=0.003..0.003
> rows=0 loops=1)
>  Index Cond: (activitygrouprelation.activityid = crmentity.crmid)
>  -> Index Scan using groups_groupname_idx on groups (cost=0.00..0.27 rows=1
> width=26) (actual time=0.001..0.001 rows=0 loops=1)
>  Index Cond: ((groups.groupname)::text =
> (activitygrouprelation.groupname)::text)
>  -> Index Scan using users_pkey on users (cost=0.00..0.29 rows=1 width=25)
> (actual time=0.033..0.035 rows=1 loops=1)
>  Index Cond: (crmentity.smownerid = users.id)
> Total runtime: 5.229 ms
> (22 rows)
>
>
>
> \d crmentity
>  Table "public.crmentity"
>  Column | Type | Modifiers
> --------------+-----------------------------+--------------------
> crmid | integer | not null
> smcreatorid | integer | not null default 0
> smownerid | integer | not null default 0
> modifiedby | integer | not null default 0
> setype | character varying(30) | not null
> description | text |
> createdtime | timestamp without time zone | not null
> modifiedtime | timestamp without time zone | not null
> viewedtime | timestamp without time zone |
> status | character varying(50) |
> version | integer | not null default 0
> presence | integer | default 1
> deleted | integer | not null default 0
> Indexes:
>  "crmentity_pkey" PRIMARY KEY, btree (crmid)
>  "crmentity_createdtime_idx" btree (createdtime)
>  "crmentity_modifiedby_idx" btree (modifiedby)
>  "crmentity_modifiedtime_idx" btree (modifiedtime)
>  "crmentity_smcreatorid_idx" btree (smcreatorid)
>  "crmentity_smownerid_idx" btree (smownerid)
>  "ftx_en_crmentity_description" gin (to_tsvector('vcrm_en'::regconfig,
> for_fts(description)))
>  "crmentity_deleted_idx" btree (deleted)
> Referenced by:
>  TABLE "service" CONSTRAINT "fk_1_service" FOREIGN KEY (serviceid)
> REFERENCES crmentity(crmid) ON DELETE CASCADE
>  TABLE "cc2crmentity" CONSTRAINT "fk_cc2crmentity_crmentity" FOREIGN KEY
> (crm_id) REFERENCES crmentity(crmid) ON UPDATE CASCADE ON DELETE CASCADE
>
>
> \d activity
>
>  Table "public.activity"
>  Column | Type | Modifiers
> ------------------+------------------------+-------------------------------------------
> activityid | integer | not null default 0
> subject | character varying(250) | not null
> semodule | character varying(20) |
> activitytype | character varying(200) | not null
> date_start | date | not null
> due_date | date |
> time_start | character varying(50) |
> time_end | character varying(50) |
> sendnotification | character varying(3) | not null default '0'::character
> varying
> duration_hours | character varying(2) |
> duration_minutes | character varying(200) |
> status | character varying(200) |
> eventstatus | character varying(200) |
> priority | character varying(200) |
> location | character varying(150) |
> notime | character varying(3) | not null default '0'::character varying
> visibility | character varying(50) | not null default 'all'::character
> varying
> recurringtype | character varying(200) |
> end_date | date |
> end_time | character varying(50) |
> Indexes:
>  "activity_pkey" PRIMARY KEY, btree (activityid)
>  "activity_activitytype_idx" btree (activitytype)
>  "activity_date_start_idx" btree (date_start)
>  "activity_due_date_idx" btree (due_date)
>  "activity_eventstatus_idx" btree (eventstatus)
>  "activity_status_idx" btree (status)
>  "activity_subject_idx" btree (subject)
>  "activity_time_start_idx" btree (time_start)
>  "ftx_en_activity_subject" gin (to_tsvector('vcrm_en'::regconfig,
> for_fts(subject::text)))
>

 	Regards,
 		Oleg
_____________________________________________________________
Oleg Bartunov, Research Scientist, Head of AstroNet (www.astronet.ru),
Sternberg Astronomical Institute, Moscow University, Russia
Internet: oleg(at)sai(dot)msu(dot)su, http://www.sai.msu.su/~megera/
phone: +007(495)939-16-83, +007(495)939-23-83

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Subject: Re: Full Text index is not using during OR operation
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Subject: Re: SELECT INTO large FKyed table is slow

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