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Re: query causes connection termination - Mailing list pgsql-general

From	Neto pr
Subject	Re: query causes connection termination
Date	November 23, 2017 06:25:55
Msg-id	CA+TZvYLXHgXVLEZyQK2H=9L0_UqMFENtQZ5tZcot7us_GMDtCA@mail.gmail.com Whole thread Raw
In response to	Re: query causes connection termination (Neto pr <netoprbr9@gmail.com>)
Responses	Re: query causes connection termination
List	pgsql-general

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Another fact is that when executing the query without the command EXPLAIN ANALYZE, the result is usually returned after a few minutes.

I do not understand, because when using the EXPLAIN ANALYZE command the dbms closes the connection.

Anyone have any tips on why this occurs?

2017-11-22 21:19 GMT-03:00 Neto pr <netoprbr9@gmail.com>:

Only complementing
I use postgresql version 10.
However the postgresql.conf file has standard settings.
My server is a 2.8 GHz Xeon (4 core) and SSDs disc.

2017-11-22 21:12 GMT-03:00 Neto pr <netoprbr9@gmail.com>:
Dear all,
when executing a query, it causes the database to close the connection.
See the error reported by the SQL TOOL DBEAVER tool:

----- -------- DBEAVER SQL tool---------------------------------
An I / O error occurred while sending to the backend.
java.io.EOFException:
---------------------------------------------------------------------------

I tried to execute the query in PSQL but the same thing happens. The query is the 19 of the TPC-H Benchmark.

---------------PSQL Cliente Sql --------------------------
tpch40gnorssd=# EXPLAIN (ANALYZE) select sum(l_extendedprice* (1 - l_discount)) as revenue
tpch40gnorssd-# from lineitem, part
tpch40gnorssd-# where (
tpch40gnorssd(# part.p_partkey = lineitem.l_partkey
tpch40gnorssd(# and part.p_brand = 'Brand#54'
tpch40gnorssd(# and part.p_container in ('SM CASE', 'SM BOX', 'SM PACK', 'SM PKG')
tpch40gnorssd(# and lineitem.l_quantity >= 4 and lineitem.l_quantity <= 4 + 10
tpch40gnorssd(# and part.p_size between 1 and 5
tpch40gnorssd(# and lineitem.l_shipmode in ('AIR', 'AIR REG')
tpch40gnorssd(# and lineitem.l_shipinstruct = 'DELIVER IN PERSON'
tpch40gnorssd(# )
tpch40gnorssd-# or
tpch40gnorssd-# (
tpch40gnorssd(# part.p_partkey = lineitem.l_partkey
tpch40gnorssd(# and part.p_brand = 'Brand#51'
tpch40gnorssd(# and part.p_container in ('MED BAG', 'MED BOX', 'MED PKG', 'MED PACK')
tpch40gnorssd(# and lineitem.l_quantity >= 11 and lineitem.l_quantity <= 11 + 10
tpch40gnorssd(# and part.p_size between 1 and 10
tpch40gnorssd(# and lineitem.l_shipmode in ('AIR', 'AIR REG')
tpch40gnorssd(# and lineitem.l_shipinstruct = 'DELIVER IN PERSON'
tpch40gnorssd(# )
tpch40gnorssd-# or
tpch40gnorssd-# (
tpch40gnorssd(# part.p_partkey = lineitem.l_partkey
tpch40gnorssd(# and part.p_brand = 'Brand#21'
tpch40gnorssd(# and part.p_container in ('LG CASE', 'LG BOX', 'LG PACK', 'LG PKG')
tpch40gnorssd(# and lineitem.l_quantity >= 28 and lineitem.l_quantity <= 28 + 10
tpch40gnorssd(# and part.p_size between 1 and 15
tpch40gnorssd(# and lineitem.l_shipmode in ('AIR', 'AIR REG')
tpch40gnorssd(# and lineitem.l_shipinstruct = 'DELIVER IN PERSON'
tpch40gnorssd(# );

server closed the connection unexpectedly
This probably means the server terminated abnormally
before or while processing the request.
The connection to the server was lost. Attempting reset: Failed.
!>
!>
------------------------------------------------------------------------

However, when executing an Explain query, no error is reported.

------------- EXPLAIN ONLY ------------------------

Finalize Aggregate (cost=280394.81..280394.82 rows=1 width=32)
-> Gather (cost=280394.59..280394.80 rows=2 width=32)
Workers Planned: 2
-> Partial Aggregate (cost=279394.59..279394.60 rows=1 width=32)
-> Nested Loop (cost=29935.44..279381.95 rows=1685 width=12)
-> Parallel Bitmap Heap Scan on part (cost=29934.87..48103.87 rows=7853 width=30)
Recheck Cond: (((p_brand = 'Brand#54'::bpchar) AND (p_size <= 5) AND (p_size >= 1) AND (p_container = ANY ('{"SM CASE","SM BOX","SM PACK","SM PKG"}'::bpchar[]))) OR ((p_brand =
'Brand#51'::bpchar) AND (p_size <= 10) AND (p_size >= 1) AND (p_container = ANY ('{"MED BAG","MED BOX","MED PKG","MED PACK"}'::bpchar[]))) OR ((p_brand = 'Brand#21'::bpchar) AND (p_size <= 15) AND (p_si
ze >= 1) AND (p_container = ANY ('{"LG CASE","LG BOX","LG PACK","LG PKG"}'::bpchar[]))))
-> BitmapOr (cost=29934.87..29934.87 rows=18861 width=0)
-> BitmapAnd (cost=9559.76..9559.76 rows=3140 width=0)
-> Bitmap Index Scan on idx_p_brand_p_size (cost=0.00..508.37 rows=31035 width=0)
Index Cond: ((p_brand = 'Brand#54'::bpchar) AND (p_size <= 5) AND (p_size >= 1))
-> Bitmap Index Scan on idx_p_containerpart000 (cost=0.00..9041.72 rows=809333 width=0)
Index Cond: (p_container = ANY ('{"SM CASE","SM BOX","SM PACK","SM PKG"}'::bpchar[]))
-> BitmapAnd (cost=9837.67..9837.67 rows=6022 width=0)
-> Bitmap Index Scan on idx_p_brand_p_size (cost=0.00..997.27 rows=60947 width=0)
Index Cond: ((p_brand = 'Brand#51'::bpchar) AND (p_size <= 10) AND (p_size >= 1))
-> Bitmap Index Scan on idx_p_containerpart000 (cost=0.00..8830.73 rows=790400 width=0)
Index Cond: (p_container = ANY ('{"MED BAG","MED BOX","MED PKG","MED PACK"}'::bpchar[]))
-> BitmapAnd (cost=10536.93..10536.93 rows=9700 width=0)
-> Bitmap Index Scan on idx_p_brand_p_size (cost=0.00..1586.52 rows=96967 width=0)
Index Cond: ((p_brand = 'Brand#21'::bpchar) AND (p_size <= 15) AND (p_size >= 1))
-> Bitmap Index Scan on idx_p_containerpart000 (cost=0.00..8940.74 rows=800267 width=0)
Index Cond: (p_container = ANY ('{"LG CASE","LG BOX","LG PACK","LG PKG"}'::bpchar[]))
-> Index Scan using idx_l_partkeylineitem000 on lineitem (cost=0.57..29.44 rows=1 width=25)
Index Cond: (l_partkey = part.p_partkey)
Filter: ((l_shipmode = ANY ('{AIR,"AIR REG"}'::bpchar[])) AND (l_shipinstruct = 'DELIVER IN PERSON'::bpchar) AND (((l_quantity >= '4'::numeric) AND (l_quantity <= '14'::numeric
)) OR ((l_quantity >= '11'::numeric) AND (l_quantity <= '21'::numeric)) OR ((l_quantity >= '28'::numeric) AND (l_quantity <= '38'::numeric))) AND (((part.p_brand = 'Brand#54'::bpchar) AND (part.p_contain
er = ANY ('{"SM CASE","SM BOX","SM PACK","SM PKG"}'::bpchar[])) AND (l_quantity >= '4'::numeric) AND (l_quantity <= '14'::numeric) AND (part.p_size <= 5)) OR ((part.p_brand = 'Brand#51'::bpchar) AND (par
t.p_container = ANY ('{"MED BAG","MED BOX","MED PKG","MED PACK"}'::bpchar[])) AND (l_quantity >= '11'::numeric) AND (l_quantity <= '21'::numeric) AND (part.p_size <= 10)) OR ((part.p_brand = 'Brand#21'::
bpchar) AND (part.p_container = ANY ('{"LG CASE","LG BOX","LG PACK","LG PKG"}'::bpchar[])) AND (l_quantity >= '28'::numeric) AND (l_quantity <= '38'::numeric) AND (part.p_size <= 15))))
(26 rows)
--------------------------------------------------------

I checked it and the DBMS has a lot of space yet. I also have no concurrent connections, because the environment is development.
Anyone have any idea why a query can cause the database to close the connection ?

Best Regards
Neto

pgsql-general by date:

From: Neto pr
Date: 23 November 2017, 06:19:28
Subject: Re: query causes connection termination

From: Tomas Vondra
Date: 23 November 2017, 06:32:20
Subject: Re: query causes connection termination

Re: query causes connection termination - Mailing list pgsql-general

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