Initial insert

Hi,
I'm trying to create datas on an initial import and i'm encountering a
performance issue.
I've 2 tables, my process create a record in each table and execute a sum
with join on this 2 tables. (and other requests but there are very fast)

My 2 tables are empty before the import.

My count query is :
select sum(quantitest0_.quantite_valeur) as col_0_0_ from dm5_quantitestock
quantitest0_, dm5_caracteristiquearticlestock caracteris1_ where
quantitest0_.id_caracteristiquearticlestock=caracteris1_.id and
caracteris1_.id_article='4028804c4a311178014a346546967c59'

i use parameterized request.

My process create only 6000 records in each table.

During the whole process this sum request lasts longer and longer.

The auto-explain plan show an seq scan

----------
Query Text: select sum(quantitest0_.quantite_valeur) as col_0_0_ from
dm5_quantitestock quantitest0_, dm5_caracteristiquearticlestock
caracteris1_ where
quantitest0_.id_caracteristiquearticlestock=caracteris1_.id and
caracteris1_.id_article=$1
Aggregate (cost=2.04..2.05 rows=1 width=26) (actual
time=862.621..862.621 rows=1 loops=1)
Output: sum(quantitest0_.quantite_valeur)
-> Nested Loop (cost=0.00..2.04 rows=1 width=26) (actual
time=862.618..862.618 rows=0 loops=1)
Output: quantitest0_.quantite_valeur
Join Filter:
((quantitest0_.id_caracteristiquearticlestock)::text =
(caracteris1_.id)::text)
Rows Removed by Join Filter: 1869
-> Seq Scan on public.dm5_quantitestock quantitest0_
(cost=0.00..1.01 rows=1 width=164) (actual time=0.004..0.408 rows=1869
loops=1)
Output: quantitest0_.id,
quantitest0_.datefinvalidite, quantitest0_.quantite_valeur,
quantitest0_.id_caracteristiquearticlestock,
quantitest0_.id_caracteristiquelieustock, quantitest0_.datecreationsysteme,
quantitest0_.datemodificationsysteme, quantitest0_.id_creeparsysteme,
quantitest0_.id_modifieparsysteme
-> Seq Scan on public.dm5_caracteristiquearticlestock
caracteris1_ (cost=0.00..1.01 rows=1 width=42) (actual time=0.456..0.456
rows=1 loops=1869)
Output: caracteris1_.id,
caracteris1_.datefinvalidite, caracteris1_.id_lot, caracteris1_.id_article,
caracteris1_.id_numeroserie, caracteris1_.datecreationsysteme,
caracteris1_.datemodificationsysteme, caracteris1_.id_modifieparsysteme,
caracteris1_.id_creeparsysteme
Filter: ((caracteris1_.id_article)::text = ($1)::text)
Rows Removed by Filter: 1869
-----------

if a launch an analyse during the process, the explain use index, but the
time remains the same.

---------
Query Text: select sum(quantitest0_.quantite_valeur) as col_0_0_ from
dm5_quantitestock quantitest0_, dm5_caracteristiquearticlestock
caracteris1_ where
quantitest0_.id_caracteristiquearticlestock=caracteris1_.id and
caracteris1_.id_article=$1
Aggregate (cost=16.55..16.56 rows=1 width=26) (actual
time=654.998..654.998 rows=1 loops=1)
Output: sum(quantitest0_.quantite_valeur)
-> Nested Loop (cost=0.00..16.55 rows=1 width=26) (actual
time=654.994..654.994 rows=0 loops=1)
Output: quantitest0_.quantite_valeur
Join Filter: ((quantitest0_.id_caracteristiquearticlestock)::text =
(caracteris1_.id)::text)
Rows Removed by Join Filter: 1651
-> Index Scan using x_dm5_quantitestock_00 on
public.dm5_quantitestock quantitest0_ (cost=0.00..8.27 rows=1 width=164)
(actual time=0.011..0.579 rows=1651 loops=1)
Output: quantitest0_.id, quantitest0_.datefinvalidite,
quantitest0_.quantite_valeur, quantitest0_.id_caracteristiquearticlestock,
quantitest0_.id_caracteristiquelieustock, quantitest0_.datecreationsysteme,
quantitest0_.datemodificationsysteme, quantitest0_.id_creeparsysteme,
quantitest0_.id_modifieparsysteme
-> Index Scan using dm5_caracteristiquearticlestock_pkey on
public.dm5_caracteristiquearticlestock caracteris1_ (cost=0.00..8.27
rows=1 width=42) (actual time=0.395..0.395 rows=1 loops=1651)
Output: caracteris1_.id, caracteris1_.datefinvalidite,
caracteris1_.id_lot, caracteris1_.id_article, caracteris1_.id_numeroserie,
caracteris1_.datecreationsysteme, caracteris1_.datemodificationsysteme,
caracteris1_.id_modifieparsysteme, caracteris1_.id_creeparsysteme
Filter: ((caracteris1_.id_article)::text =
'4028804c4a311178014a346547307cce'::text)
Rows Removed by Filter: 1651

----------

If i create the first 1000 records, commit and end transaction, the whole
import is very fast.

I can't change my process to cut the process in little part...

An idea ?

Thanks.

*Laurent CATHALA*Architecte
lca(at)sylob(dot)com

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