Thread: PostgreSQL array, recursion and more
MESH Data Tree:
example:
Hallux;A01.378.610.250.300.792.380
where:
A01 is Body Regions
A01.378 is Extremities
A01.378.610 is Lower Extremity
A01.378.610.250 is Foot
A01.378.610.250.300 is Forefoot, Human
A01.378.610.250.300.792 is Toes
CREATE OR REPLACE FUNCTION mesh_split(text) RETURNS text[]
AS $$
return [split('\.',$_[0])];
$$ LANGUAGE plperlu;
arancia=# select mesh_split('A01.378.610.250.300.792.380');
mesh_split
-------------------------------
{A01,378,610,250,300,792,380}
(1 row)
/*
Is it a real array?
If it is, why can I not use index to access its items?
*/
arancia=# select mesh_split('A01.378.610.250.300.792.380')[1];
ERROR: syntax error at or near "["
LINE 1: select mesh_split('A01.378.610.250.300.792.380')[1];
^
/*
but it is an array, it behaves as it is.
*/
arancia=> select array_length(mesh_split('A01.378.610.250.300.792.380'),1);
array_length
--------------
7
(1 row)
/* How to get access to its items then?
*/
Another problem related:
arancia=> select * from meshtree where code = ANY
mesh_split('A01.378.610.250.300.792.380');
ERROR: syntax error at or near "mesh_split"
LINE 1: select * from meshtree where code = ANY mesh_split('A01.378....
^
select * from meshtree,
unnest(mesh_split('A01.378.610.250.300.792.380')) as c where
c=meshtree.code;
parent | id | code | description
--------+-------+------+-------------------------------------------------------------------
10 | 11 | 300 | Dehydroepiandrosterone Sulfate
33 | 34 | 250 | Cymarine
48 | 49 | 250 | Cymarine
61 | 62 | 250 | Dihydrotachysterol
66 | 68 | 300 | Calcitriol
65 | 69 | 250 | Calcifediol
92 | 93 | 380 | Glycodeoxycholic Acid
98 | 99 | 250 | Finasteride
111 | 117 | 300 | Chenodeoxycholic Acid
145 | 146 | 300 | Dehydroepiandrosterone Sulfate
180 | 182 | 250 | Ethinyl Estradiol-Norgestrel Combination
190 | 191 | 250 | Desoximetasone
[..]
| 18638 | A01 | Body Regions
[..]
190 | 192 | 300 | Dexamethasone Isonicotinate
195 | 196 | 250 | Clobetasol
199 | 200 | 300 | Fluocinonide
206 | 207 | 250 | Diflucortolone
266 | 267 | 300 | Dexamethasone Isonicotinate
281 | 282 | 250 | Diflucortolone
290 | 293 | 250 | Dehydrocholesterols
305 | 306 | 250 | Dihydrotachysterol
312 | 314 | 300 | Calcitriol
311 | 315 | 250 | Calcifediol
320 | 321 | 250 | Cholestanol
328 | 330 | 300 | Calcitriol
[..]
52135 | 52136 | 250 | Eye Injuries
52136 | 52137 | 250 | Eye Burns
52149 | 52155 | 300 | Hematoma, Epidural, Cranial
52181 | 52196 | 300 | Gallbladder Emptying
52269 | 52277 | 300 | Caplan Syndrome
52360 | 52368 | 300 | Caplan Syndrome
52428 | 52442 | 380 | Hemothorax
52476 | 52491 | 610 | Pneumonia
52534 | 52535 | 380 | Legionnaires' Disease
(2204 rows)
I really want to write better similar query:
arancia=> with recursive t(id,parent,codeparts,idx,last,descriptions) as (
SELECT
id, parent, mesh_split('A01.378.610.250.300.792.380'), 1,
array_length(mesh_split('A01.378.610.250.300.792.380'),1),
ARRAY[description]
FROM meshtree WHERE code='A01'
UNION ALL
SELECT m.id, m.parent, t.codeparts, idx+1, last, descriptions ||
ARRAY[description]
FROM meshtree AS m JOIN t ON (t.id=m.parent)
WHERE idx<=last AND m.code=t.codeparts[idx+1])
SELECT t.* FROM t;
id | parent | codeparts | idx | last |
descriptions
-------+--------+-------------------------------+-----+------+--------...
18638 | | {A01,378,610,250,300,792,380} | 1 | 7 | {"Body
Regions"}
18675 | 18638 | {A01,378,610,250,300,792,380} | 2 | 7 | {"Body
Regions",Extremities}
18676 | 18675 | {A01,378,610,250,300,792,380} | 3 | 7 | {"Body
Regions",Extremities,"Lower Extremity"}
18679 | 18676 | {A01,378,610,250,300,792,380} | 4 | 7 | {"Body
Regions",Extremities,"Lower Extremity",Foot}
18682 | 18679 | {A01,378,610,250,300,792,380} | 5 | 7 | {"Body
Regions",Extremities,"Lower Extremity",Foot,"Forefoot, Human"}
18683 | 18682 | {A01,378,610,250,300,792,380} | 6 | 7 | {"Body
Regions",Extremities,"Lower Extremity",Foot,"Forefoot, Human",Toes}
18684 | 18683 | {A01,378,610,250,300,792,380} | 7 | 7 | {"Body
Regions",Extremities,"Lower Extremity",Foot,"Forefoot, Human",Toes,Hallux}
(7 rows)
explain analyze with recursive
t(id,parent,codeparts,idx,last,descriptions) as (
select
id,parent,mesh_split('A01.378.610.250.300.792.380'),1,array_length(mesh_split('A01.378.610.250.300.792.380'),1),ARRAY[description]
from meshtree where code='A01'
union all
select m.id,m.parent,t.codeparts,idx+1,last,descriptions ||
ARRAY[description] from meshtree as m join t on (t.id=m.parent) where
idx<=last and m.code=t.codeparts[idx+1]) select t.* from t;
QUERY PLAN
------------------------------------------------------------------------------------------------------------------------------------------------------
CTE Scan on t (cost=6336.53..6337.17 rows=32 width=80) (actual
time=4.850..9.453 rows=7 loops=1)
CTE t
-> Recursive Union (cost=0.00..6336.53 rows=32 width=99) (actual
time=4.839..9.397 rows=7 loops=1)
-> Index Scan using meshtree_id_code on meshtree
(cost=0.00..1030.38 rows=22 width=27) (actual time=4.828..8.895 rows=1
loops=1)
Index Cond: (code = 'A01'::text)
-> Nested Loop (cost=0.00..530.55 rows=1 width=99) (actual
time=0.051..0.061 rows=1 loops=7)
-> WorkTable Scan on t (cost=0.00..4.95 rows=73
width=76) (actual time=0.005..0.008 rows=1 loops=7)
Filter: (idx <= last)
-> Index Scan using meshtree_parent_code on meshtree
m (cost=0.00..7.18 rows=1 width=31) (actual time=0.031..0.034 rows=1
loops=7)
Index Cond: ((m.parent = t.id) AND (m.code =
t.codeparts[(t.idx + 1)]))
Total runtime: 9.758 ms
(11 rows)
PostgreSQL rocks!
Thank you in advance, \ferz
Attachment
Στις Wednesday 17 November 2010 15:22:34 ο/η Ferruccio Zamuner έγραψε:
>
> /* How to get access to its items then?
> */
select (mesh_split('A01.378.610.250.300.792.380')::text[])[1];
--
Achilleas Mantzios
Hey Ferruccio,<br /><br />Also consider ltree contrib module as alternative.<br /><a href="http://www.postgresql.org/docs/9.0/static/ltree.html">http://www.postgresql.org/docs/9.0/static/ltree.html</a><br /><br/>;-)<br /><br /><div class="gmail_quote"> 2010/11/17 Ferruccio Zamuner <span dir="ltr"><<a href="mailto:nonsolosoft@diff.org">nonsolosoft@diff.org</a>></span><br/><blockquote class="gmail_quote" style="margin:0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;"> MESH Data Tree:<br /><br/> example:<br /> Hallux;A01.378.610.250.300.792.380<br /><br /> where:<br /> A01 is Body Regions<br /> A01.378 is Extremities<br/> A01.378.610 is Lower Extremity<br /> A01.378.610.250 is Foot<br /> A01.378.610.250.300 is Forefoot, Human<br/> A01.378.610.250.300.792 is Toes<br /><br /> CREATE OR REPLACE FUNCTION mesh_split(text) RETURNS text[]<br /> AS$$<br /> return [split('\.',$_[0])];<br /> $$ LANGUAGE plperlu;<br /><br /> arancia=# select mesh_split('A01.378.610.250.300.792.380');<br/> mesh_split<br /> -------------------------------<br /> {A01,378,610,250,300,792,380}<br/> (1 row)<br /><br /><br /> /*<br /> Is it a real array?<br /> If it is, why can Inot use index to access its items?<br /> */<br /><br /> arancia=# select mesh_split('A01.378.610.250.300.792.380')[1];<br/> ERROR: syntax error at or near "["<br /> LINE 1: select mesh_split('A01.378.610.250.300.792.380')[1];<br/> ^<br /> /*<br /> but it is an array, it behaves as it is.<br /> */<br /> arancia=> select array_length(mesh_split('A01.378.610.250.300.792.380'),1);<br/> array_length<br /> --------------<br /> 7<br/> (1 row)<br /><br /> /* How to get access to its items then?<br /> */<br /><br /><br /> Another problem related:<br/><br /> arancia=> select * from meshtree where code = ANY mesh_split('A01.378.610.250.300.792.380');<br />ERROR: syntax error at or near "mesh_split"<br /> LINE 1: select * from meshtree where code = ANY mesh_split('A01.378....<br/> ^<br /><br /> select * from meshtree, unnest(mesh_split('A01.378.610.250.300.792.380'))as c where c=meshtree.code;<br /> parent | id | code | description <br /> --------+-------+------+-------------------------------------------------------------------<br/> 10 | 11 | 300 |Dehydroepiandrosterone Sulfate<br /> 33 | 34 | 250 | Cymarine<br /> 48 | 49 | 250 | Cymarine<br /> 61 | 62 | 250 | Dihydrotachysterol<br /> 66 | 68 | 300 | Calcitriol<br /> 65 | 69 | 250 | Calcifediol<br/> 92 | 93 | 380 | Glycodeoxycholic Acid<br /> 98 | 99 | 250 | Finasteride<br /> 111 | 117 | 300 | Chenodeoxycholic Acid<br /> 145 | 146 | 300 | Dehydroepiandrosterone Sulfate<br /> 180 | 182 | 250 | Ethinyl Estradiol-Norgestrel Combination<br /> 190 | 191 | 250 | Desoximetasone<br /> [..]<br /> | 18638| A01 | Body Regions<br /> [..]<br /> 190 | 192 | 300 | Dexamethasone Isonicotinate<br /> 195 | 196 | 250 | Clobetasol<br /> 199 | 200 | 300 | Fluocinonide<br /> 206 | 207 | 250 | Diflucortolone<br /> 266 | 267 | 300 | Dexamethasone Isonicotinate<br /> 281 | 282 | 250 | Diflucortolone<br /> 290 | 293 | 250 | Dehydrocholesterols<br/> 305 | 306 | 250 | Dihydrotachysterol<br /> 312 | 314 | 300 | Calcitriol<br /> 311| 315 | 250 | Calcifediol<br /> 320 | 321 | 250 | Cholestanol<br /> 328 | 330 | 300 | Calcitriol<br />[..]<br /> 52135 | 52136 | 250 | Eye Injuries<br /> 52136 | 52137 | 250 | Eye Burns<br /> 52149 | 52155 | 300 | Hematoma,Epidural, Cranial<br /> 52181 | 52196 | 300 | Gallbladder Emptying<br /> 52269 | 52277 | 300 | Caplan Syndrome<br/> 52360 | 52368 | 300 | Caplan Syndrome<br /> 52428 | 52442 | 380 | Hemothorax<br /> 52476 | 52491 | 610 | Pneumonia<br /> 52534 | 52535 | 380 | Legionnaires' Disease<br /> (2204 rows)<br /><br /> I really want to writebetter similar query:<br /><br /> arancia=> with recursive t(id,parent,codeparts,idx,last,descriptions) as (<br /> SELECT<br /> id, parent, mesh_split('A01.378.610.250.300.792.380'), 1, array_length(mesh_split('A01.378.610.250.300.792.380'),1),ARRAY[description]<br /> FROM meshtree WHERE code='A01'<br /> UNION ALL<br /> SELECT <a href="http://m.id" target="_blank">m.id</a>, m.parent, t.codeparts, idx+1, last, descriptions|| ARRAY[description]<br /> FROM meshtree AS m JOIN t ON (<a href="http://t.id" target="_blank">t.id</a>=m.parent)<br/> WHERE idx<=last AND m.code=t.codeparts[idx+1])<br /> SELECT t.* FROM t;<br/> id | parent | codeparts | idx | last | descriptions<br /> -------+--------+-------------------------------+-----+------+--------...<br/> 18638 | | {A01,378,610,250,300,792,380}| 1 | 7 | {"Body Regions"}<br /> 18675 | 18638 | {A01,378,610,250,300,792,380} | 2| 7 | {"Body Regions",Extremities}<br /> 18676 | 18675 | {A01,378,610,250,300,792,380} | 3 | 7 | {"Body Regions",Extremities,"LowerExtremity"}<br /> 18679 | 18676 | {A01,378,610,250,300,792,380} | 4 | 7 | {"Body Regions",Extremities,"LowerExtremity",Foot}<br /> 18682 | 18679 | {A01,378,610,250,300,792,380} | 5 | 7 | {"Body Regions",Extremities,"LowerExtremity",Foot,"Forefoot, Human"}<br /> 18683 | 18682 | {A01,378,610,250,300,792,380} | 6| 7 | {"Body Regions",Extremities,"Lower Extremity",Foot,"Forefoot, Human",Toes}<br /> 18684 | 18683 | {A01,378,610,250,300,792,380}| 7 | 7 | {"Body Regions",Extremities,"Lower Extremity",Foot,"Forefoot, Human",Toes,Hallux}<br/> (7 rows)<br /><br /> explain analyze with recursive t(id,parent,codeparts,idx,last,descriptions)as (<br /> select id,parent,mesh_split('A01.378.610.250.300.792.380'),1,array_length(mesh_split('A01.378.610.250.300.792.380'),1),ARRAY[description] frommeshtree where code='A01'<br /> union all<br /> select <a href="http://m.id" target="_blank">m.id</a>,m.parent,t.codeparts,idx+1,last,descriptions|| ARRAY[description] from meshtree as m join t on (<ahref="http://t.id" target="_blank">t.id</a>=m.parent) where idx<=last and m.code=t.codeparts[idx+1]) select t.* fromt;<br /><br /> QUERY PLAN <br /> ------------------------------------------------------------------------------------------------------------------------------------------------------<br /> CTE Scan on t (cost=6336.53..6337.17 rows=32 width=80) (actual time=4.850..9.453 rows=7 loops=1)<br /> CTE t<br /> -> Recursive Union (cost=0.00..6336.53 rows=32 width=99) (actual time=4.839..9.397 rows=7 loops=1)<br /> -> Index Scan using meshtree_id_code on meshtree (cost=0.00..1030.38 rows=22 width=27) (actual time=4.828..8.895rows=1 loops=1)<br /> Index Cond: (code = 'A01'::text)<br /> -> Nested Loop (cost=0.00..530.55 rows=1 width=99) (actual time=0.051..0.061 rows=1 loops=7)<br /> -> WorkTableScan on t (cost=0.00..4.95 rows=73 width=76) (actual time=0.005..0.008 rows=1 loops=7)<br /> Filter: (idx <= last)<br /> -> Index Scan using meshtree_parent_code on meshtree m (cost=0.00..7.18rows=1 width=31) (actual time=0.031..0.034 rows=1 loops=7)<br /> Index Cond: ((m.parent= <a href="http://t.id" target="_blank">t.id</a>) AND (m.code = t.codeparts[(t.idx + 1)]))<br /> Total runtime:9.758 ms<br /> (11 rows)<br /><br /><br /> PostgreSQL rocks!<br /><br /><br /> Thank you in advance, \ferz<br /><br /><br /> --<br /> Sent via pgsql-sql mailing list (<a href="mailto:pgsql-sql@postgresql.org">pgsql-sql@postgresql.org</a>)<br/> To make changes to your subscription:<br /><a href="http://www.postgresql.org/mailpref/pgsql-sql"target="_blank">http://www.postgresql.org/mailpref/pgsql-sql</a><br /><br/></blockquote></div><br /><br clear="all" /><br />-- <br />// Dmitriy.<br /><br /><br />