RE: Postgres DB Slowness

<[email protected]> Mon, 26 Aug 2019 10:14:20 +0000

Newsgroups	gmane.comp.db.postgresql.admin
Message-ID	<2A91BEF8171A5349931391E0C721CC535B627ADE@CPEMS-KPN501.KPNCNL.LOCAL>




-----Original Message-----
From: Juan José Santamaría Flecha <[email protected]>
Sent: Friday, August 23, 2019 1:08 PM
To: Bhattacharjee, Soumik <[email protected]>
Cc: [email protected]; [email protected]
Subject: Re: Postgres DB Slowness



On Fri, Aug 23, 2019 at 10:17 AM <[email protected]<mailto:[email protected]>> wrote:

>

> Query

> ===========

> SELECT

>     i.*

> FROM

>     npcurren.num_cps_instelling i,

>     npcurren.num_aangesloten_nr n

> WHERE

>     n.fk_exploit_nop_int_oper_id = 'PTT'

>     AND i.telefoonnummer != n.anr_nummer_hoog

>     AND i.telefoonnummer != n.anr_nummer_laag;

>

> Explain Plan

> ======================

> "Nested Loop  (cost=2068.47..1769226624.33 rows=101090505159 width=73)"

>



This query looks wrong, resulting in a cartesian join.



As other people have pointed out, the execution times do not seem reasonable, could you change the 'SELECT *' into a 'SELECT count(1)'

for the comparison?



Regards,



Juan José Santamaría Flecha



-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



Hi Juan,



The query plan is below -



numbes_test=# explain analyze select i.* from npcurren.NUM_CPS_INSTELLING i, npcurren.NUM_AANGESLOTEN_NR n where n.FK_EXPLOIT_NOP_INT_OPER_ID = 'PTT' and i.TELEFOONNUMMER != n.ANR_NUMMER_HOOG and i.TELEFOONNUMMER != n.ANR_NUMMER_LAAG;Â



                                                                       QUERY PLAN

--------------------------------------------------------------------------------------------------------------------------------------------------------

Nested Loop  (cost=2071.86..1817248003.24 rows=103834572306 width=73) (actual time=68.512..28074371.506 rows=98046804138 loops=1)

   Join Filter: (((i.telefoonnummer)::text <> (n.anr_nummer_hoog)::text) AND ((i.telefoonnummer)::text <> (n.anr_nummer_laag)::text))

   Rows Removed by Join Filter: 36398

   ->  Seq Scan on num_cps_instelling i  (cost=0.00..12485.52 rows=539852 width=73) (actual time=0.069..403.077 rows=539852 loops=1)

   ->  Materialize  (cost=2071.86..130606.58 rows=192339 width=22) (actual time=0.002..16.490 rows=181618 loops=539852)

         ->  Bitmap Heap Scan on num_aangesloten_nr n  (cost=2071.86..129644.88 rows=192339 width=22) (actual time=68.425..555.068 rows=181618 loops=1)

               Recheck Cond: ((fk_exploit_nop_int_oper_id)::text = 'PTT'::text)

               Heap Blocks: exact=51470

               ->  Bitmap Index Scan on anr_idx6  (cost=0.00..2023.78 rows=192339 width=0) (actual time=59.276..59.276 rows=181618 loops=1)

                     Index Cond: ((fk_exploit_nop_int_oper_id)::text = 'PTT'::text)

Planning time: 4.702 ms

Execution time: 31536903.127 ms

(12 rows)









Does this also looks bad for performance with Data types- as there is varchar in a number records field ? - The table DDL is attached



    anr_nummer_laag character varying(20) COLLATE pg_catalog."default" NOT NULL,

    anr_nummer_hoog character varying(20) COLLATE pg_catalog."default" NOT NULL,

Table_Def.txt (text/plain, 4.1 KB)

CREATE TABLE npcurren.num_aangesloten_nr
(
    anr_nummer_laag character varying(20) COLLATE pg_catalog."default" NOT NULL,
    anr_nummer_hoog character varying(20) COLLATE pg_catalog."default" NOT NULL,
    fk_eigenaar_nop_int_oper_id character varying(6) COLLATE pg_catalog."default",
    fk_sta_id character varying(1) COLLATE pg_catalog."default",
    fk_sac_id character varying(1) COLLATE pg_catalog."default",
    fk_moeder_hst_spc_id character varying(4) COLLATE pg_catalog."default",
    fk_moeder_cgb_code integer,
    fk_exploit_nop_int_oper_id character varying(6) COLLATE pg_catalog."default",
    fk_dienst_hst_spc_id character varying(4) COLLATE pg_catalog."default",
    fk_dienst_cgb_code integer,
    anr_soort_dienst character varying(2) COLLATE pg_catalog."default",
    anr_roepnummer character varying(20) COLLATE pg_catalog."default",
    anr_lri character varying(24) COLLATE pg_catalog."default",
    anr_logisch_mutatiemoment timestamp without time zone,
    anr_technisch_mutatiemoment timestamp without time zone NOT NULL,
    anr_mutatie_gebruiker_id character varying(8) COLLATE pg_catalog."default" NOT NULL,
    anr_netnummer character varying(4) COLLATE pg_catalog."default",
    anr_heeft_cvi_dienst_jn character varying(1) COLLATE pg_catalog."default",
    fk_num_voip_platform_id smallint,
    anr_heeft_cvi_zm_dienst_yn character varying(1) COLLATE pg_catalog."default",
    anr_cvi_kenmerk character varying(10) COLLATE pg_catalog."default",
    anr_cvi_telco character varying(8) COLLATE pg_catalog."default" NOT NULL,
    CONSTRAINT anr_prx PRIMARY KEY (anr_nummer_laag),
    CONSTRAINT sys_c0012384 FOREIGN KEY (fk_sac_id)
        REFERENCES npcurren.num_soort_actie (sac_id) MATCH SIMPLE
        ON UPDATE NO ACTION
        ON DELETE NO ACTION,
    CONSTRAINT sys_c0012385 FOREIGN KEY (fk_sta_id)
        REFERENCES npcurren.num_status (sta_id) MATCH SIMPLE
        ON UPDATE NO ACTION
        ON DELETE NO ACTION,
    CONSTRAINT sys_c0012386 FOREIGN KEY (fk_num_voip_platform_id)
        REFERENCES npcurren.num_voip_platform (platform_id) MATCH SIMPLE
        ON UPDATE NO ACTION
        ON DELETE NO ACTION
)
WITH (
    OIDS = FALSE
)
TABLESPACE pg_default;

ALTER TABLE npcurren.num_aangesloten_nr
    OWNER to postgres;

-- Index: anr_idx1

-- DROP INDEX npcurren.anr_idx1;

CREATE INDEX anr_idx1
    ON npcurren.num_aangesloten_nr USING btree
    (fk_moeder_hst_spc_id COLLATE pg_catalog."default", fk_moeder_cgb_code)
    TABLESPACE pg_default;

-- Index: anr_idx2

-- DROP INDEX npcurren.anr_idx2;

CREATE INDEX anr_idx2
    ON npcurren.num_aangesloten_nr USING btree
    (fk_dienst_hst_spc_id COLLATE pg_catalog."default", fk_dienst_cgb_code)
    TABLESPACE pg_default;

-- Index: anr_idx3

-- DROP INDEX npcurren.anr_idx3;

CREATE INDEX anr_idx3
    ON npcurren.num_aangesloten_nr USING btree
    (fk_sac_id COLLATE pg_catalog."default")
    TABLESPACE pg_default;

-- Index: anr_idx4

-- DROP INDEX npcurren.anr_idx4;

CREATE INDEX anr_idx4
    ON npcurren.num_aangesloten_nr USING btree
    (fk_sta_id COLLATE pg_catalog."default")
    TABLESPACE pg_default;

-- Index: anr_idx5

-- DROP INDEX npcurren.anr_idx5;

CREATE INDEX anr_idx5
    ON npcurren.num_aangesloten_nr USING btree
    (fk_eigenaar_nop_int_oper_id COLLATE pg_catalog."default")
    TABLESPACE pg_default;

-- Index: anr_idx6

-- DROP INDEX npcurren.anr_idx6;

CREATE INDEX anr_idx6
    ON npcurren.num_aangesloten_nr USING btree
    (fk_exploit_nop_int_oper_id COLLATE pg_catalog."default")
    TABLESPACE pg_default;

-- Index: anr_idx7

-- DROP INDEX npcurren.anr_idx7;

CREATE INDEX anr_idx7
    ON npcurren.num_aangesloten_nr USING btree
    (anr_nummer_hoog COLLATE pg_catalog."default")
    TABLESPACE pg_default;

-- Index: anr_idx8

-- DROP INDEX npcurren.anr_idx8;

CREATE INDEX anr_idx8
    ON npcurren.num_aangesloten_nr USING btree
    (anr_netnummer COLLATE pg_catalog."default")
    TABLESPACE pg_default;

-- Index: anr_idx9

-- DROP INDEX npcurren.anr_idx9;

CREATE INDEX anr_idx9
    ON npcurren.num_aangesloten_nr USING btree
    (fk_num_voip_platform_id)
    TABLESPACE pg_default;