🥇 Parti Hapus neu cwpl o linellau o atgofion am ddod i adnabod rhannu yn PostgreSQL10

Rhagair neu sut y daeth y syniad o rannu i fodolaeth

Mae'r stori yn dechrau yma: Ydych chi'n cofio sut y dechreuodd y cyfan. Roedd popeth am y tro cyntaf ac eto. Ar ôl i bron yr holl adnoddau ar gyfer optimeiddio'r cais, bryd hynny, ddod i ben, cododd y cwestiwn - beth nesaf? Fel hyn y cododd y syniad o ymrannu.

Digression telynegol:
Yn union ‘ar y foment honno’, oherwydd fel y digwyddodd, roedd cronfeydd optimeiddio heb eu defnyddio... diolch asmm a Habru!

Felly, sut arall allwch chi wneud y cwsmer yn hapus, ac ar yr un pryd wella'ch sgiliau eich hun?

I symleiddio popeth cymaint â phosibl, yna dim ond dwy ffordd sydd i wella rhywbeth yn radical ym mherfformiad y gronfa ddata:
1) Llwybr helaeth - rydym yn cynyddu adnoddau, yn newid y cyfluniad;
2) llwybr dwys - optimeiddio ymholiad

Gan fy mod yn ailadrodd, bryd hynny nad oedd yn glir bellach beth arall i'w newid yn y cais i gyflymu, dewiswyd y llwybr - newidiadau dylunio tabl.

Felly, mae'r prif gwestiwn yn codi: beth a sut y byddwn yn newid?

Amodau cychwynnol

Yn gyntaf, mae'r ERD hwn (a ddangosir mewn ffordd wedi'i symleiddio'n amodol):

Nodweddion Allweddol:

perthynas lawer-i-lawer
mae gan y tabl allwedd rhaniad posibl yn barod

Cais gwreiddiol:

SELECT
            p."PARAMETER_ID" as  parameter_id,
            pc."PC_NAME" AS pc_name,
            pc."CUSTOMER_PARTNUMBER" AS customer_partnumber,
            w."LASERMARK" AS lasermark,
            w."LOTID" AS lotid,
            w."REPORTED_VALUE" AS reported_value,
            w."LOWER_SPEC_LIMIT" AS lower_spec_limit,
            w."UPPER_SPEC_LIMIT" AS upper_spec_limit,
            p."TYPE_CALCUL" AS type_calcul,
            s."SHIPMENT_NAME" AS shipment_name,
            s."SHIPMENT_DATE" AS shipment_date,
            extract(year from s."SHIPMENT_DATE") AS year,
            extract(month from s."SHIPMENT_DATE") as month,
            s."REPORT_NAME" AS report_name,
            p."SPARAM_NAME" AS SPARAM_name,
            p."CUSTOMERPARAM_NAME" AS customerparam_name
        FROM data w INNER JOIN shipment s ON s."SHIPMENT_ID" = w."SHIPMENT_ID"
             INNER JOIN parameters p ON p."PARAMETER_ID" = w."PARAMETER_ID"
             INNER JOIN shipment_pc sp ON s."SHIPMENT_ID" = sp."SHIPMENT_ID"
             INNER JOIN pc pc ON pc."PC_ID" = sp."PC_ID"
             INNER JOIN ( SELECT w2."LASERMARK" , MAX(s2."SHIPMENT_DATE") AS "SHIPMENT_DATE"
                          FROM shipment s2 INNER JOIN data w2 ON s2."SHIPMENT_ID" = w2."SHIPMENT_ID" 
                          GROUP BY w2."LASERMARK"
                         ) md ON md."SHIPMENT_DATE" = s."SHIPMENT_DATE" AND md."LASERMARK" = w."LASERMARK"
        WHERE 
             s."SHIPMENT_DATE" >= '2018-07-01' AND s."SHIPMENT_DATE" <= '2018-09-30' ;

Canlyniadau gweithredu ar y gronfa ddata prawf:
Cost : 502 997.55
Amser cyflawni: 505 eiliad.

Beth ydym ni'n ei weld? Cais rheolaidd, yn seiliedig ar dafell amser.
Gadewch i ni wneud y dybiaeth resymegol symlaf: os oes sampl o dafell amser, a fydd yn ein helpu ni? Mae hynny'n iawn - rhaniad.

Beth i'w rannu?

Ar yr olwg gyntaf, mae'r dewis yn amlwg - rhaniad datganiadol o'r tabl “cludo” gan ddefnyddio'r allwedd “SHIPMENT_DATE” (neidio yn rhy bell ymlaen - yn y diwedd trodd allan ychydig yn anghywir yn cynhyrchu).

Sut i rannu?

Nid yw'r cwestiwn hwn yn rhy anodd ychwaith. Yn ffodus, yn PostgreSQL 10, mae yna fecanwaith rhaniad dynol bellach.
Felly:

Arbedwch dymp o'r tabl ffynhonnell - pg_dump source_table
Dileu'r tabl gwreiddiol - tabl gollwng source_table
Creu bwrdd rhiant gyda rhaniad ystod - creu tabl source_table
Creu adrannau - creu tabl source_table, creu mynegai
Mewnforio'r domen a grëwyd yng ngham 1 - pg_adfer

Sgriptiau ar gyfer rhaniad

Er mwyn symlrwydd a chyfleustra, mae camau 2,3,4 wedi'u cyfuno'n un sgript.

Felly:
Arbed dymp o'r tabl ffynhonnell

pg_dump postgres --file=/dump/shipment.dmp --format=c --table=shipment --verbose > /dump/shipment.log 2>&1

Dileu'r tabl ffynhonnell + Creu tabl rhiant gyda rhaniad amrediad + Creu rhaniadau

--create_partition_shipment.sql
do language plpgsql $$
declare 
rec_shipment_date RECORD ;
partition_name varchar;
index_name varchar;
current_year varchar ;
current_month varchar ;
begin_year varchar ;
begin_month varchar ;
next_year varchar ;
next_month varchar ;
first_flag boolean ;
i integer ;
begin
  RAISE NOTICE 'CREATE TEMPORARY TABLE FOR SHIPMENT_DATE';
  CREATE TEMP TABLE tmp_shipment_date as select distinct "SHIPMENT_DATE" from shipment order by "SHIPMENT_DATE" ;

  RAISE NOTICE 'DROP TABLE shipment';
  drop table shipment cascade ;
  
  CREATE TABLE public.shipment
  (
    "SHIPMENT_ID" integer NOT NULL DEFAULT nextval('shipment_shipment_id_seq'::regclass),
    "SHIPMENT_NAME" character varying(30) COLLATE pg_catalog."default",
    "SHIPMENT_DATE" timestamp without time zone,
    "REPORT_NAME" character varying(40) COLLATE pg_catalog."default"
  )
  PARTITION BY RANGE ("SHIPMENT_DATE")
  WITH (
      OIDS = FALSE
  )
  TABLESPACE pg_default;

  RAISE NOTICE 'CREATE PARTITIONS FOR TABLE shipment';

  current_year:='0';
  current_month:='0';

  begin_year := '0' ;
  begin_month := '0'  ;
  next_year := '0' ;
  next_month := '0'  ;

  FOR rec_shipment_date IN SELECT * FROM tmp_shipment_date LOOP
      
      RAISE NOTICE 'SHIPMENT_DATE=%',rec_shipment_date."SHIPMENT_DATE";
      
      current_year := date_part('year' ,rec_shipment_date."SHIPMENT_DATE");
      current_month := date_part('month' ,rec_shipment_date."SHIPMENT_DATE") ; 

      IF to_number(current_month,'99') < 10 THEN
        current_month := '0'||current_month ; 
      END IF ;

      --Init borders
      IF   begin_year = '0' THEN
       first_flag := true ; --first time flag
       begin_year := current_year ;
       begin_month := current_month ;   
   
        IF current_month = '12' THEN
          next_year := date_part('year' ,rec_shipment_date."SHIPMENT_DATE" + interval '1 year') ;
        ELSE
          next_year := current_year ;
        END IF;
     
       next_month := date_part('month' ,rec_shipment_date."SHIPMENT_DATE" + interval '1 month') ;

      END IF;

      -- Check current date into borders NOT for First time
      IF to_date( current_year||'.'||current_month, 'YYYY.MM') >= to_date( begin_year||'.'||begin_month, 'YYYY.MM') AND 
         to_date( current_year||'.'||current_month, 'YYYY.MM') < to_date( next_year||'.'||next_month, 'YYYY.MM') AND 
         NOT first_flag 
      THEN
         CONTINUE ; 
      ELSE
       --NEW borders only for second and after time 
       begin_year := current_year ;
       begin_month := current_month ;   
   
        IF current_month = '12' THEN
          next_year := date_part('year' ,rec_shipment_date."SHIPMENT_DATE" + interval '1 year') ;
        ELSE
          next_year := current_year ;
        END IF;
     
       next_month := date_part('month' ,rec_shipment_date."SHIPMENT_DATE" + interval '1 month') ;

      END IF;      

      partition_name := 'shipment_shipment_date_'||begin_year||'-'||begin_month||'-01-'|| next_year||'-'||next_month||'-01'  ;
 
     EXECUTE format('CREATE TABLE ' || quote_ident(partition_name) || ' PARTITION OF shipment FOR VALUES FROM ( %L ) TO ( %L )  ' , current_year||'-'||current_month||'-01' , next_year||'-'||next_month||'-01'  ) ; 

      index_name := partition_name||'_shipment_id_idx';
      RAISE NOTICE 'INDEX NAME =%',index_name;
      EXECUTE format('CREATE INDEX ' || quote_ident(index_name) || ' ON '|| quote_ident(partition_name) ||' USING btree ("SHIPMENT_ID") TABLESPACE pg_default ' ) ; 

      --Drop first time flag
      first_flag := false ;
   
  END LOOP;

end
$$;

Mewnforio'r domen

pg_restore -d postgres --data-only --format=c --table=shipment --verbose  shipment.dmp > /tmp/data_dump/shipment_restore.log 2>&1

Gwirio canlyniadau rhaniad

Beth sydd gennym ni o ganlyniad? Mae testun llawn y cynllun gweithredu yn fawr ac yn ddiflas, felly mae'n eithaf posibl cyfyngu'ch hun i'r niferoedd terfynol.

Oedd

Cost: 502 997.55
Amser cyflawni: 505 eiliad.

Wedi dod yn

Cost: 77 872.36
Amser cyflawni: 79 eiliad.

Canlyniad eithaf da. Llai o gost ac amser gweithredu. Felly, mae defnyddio rhaniad yn rhoi'r effaith ddisgwyliedig ac, yn gyffredinol, nid oes unrhyw syndod.

Gwnewch y cwsmer yn hapus

Cyflwynwyd canlyniadau'r profion i'r cwsmer i'w hadolygu. Ac ar ôl ei adolygu, cawsant reithfarn braidd yn annisgwyl: “Gwych, rhannwch y tabl “data”.

Do, ond fe wnaethom archwilio tabl “cludo” hollol wahanol; nid oes gan y tabl “data” y maes “SHIPMENT_DATE”.

Dim problem, ychwanegu, newid. Y prif beth yw bod y cwsmer yn fodlon â'r canlyniad; nid yw'r manylion gweithredu yn arbennig o bwysig.

Rhannu'r prif dabl “data”

Yn gyffredinol, ni chododd unrhyw anawsterau penodol. Er, mae'r algorithm rhaniad, wrth gwrs, wedi newid rhywfaint.

Ychwanegu'r golofn “SHIPMENT_DATA” i'r tabl “data”.

psql -h хост -U база -d юзер
=> ALTER TABLE data ADD COLUMN "SHIPMENT_DATE" timestamp without time zone ;

Llenwch werthoedd y golofn “SHIPMENT_DATA” yn y tabl “data” gyda gwerthoedd y golofn o'r un enw o'r tabl “cludo”

-----------------------------
--update_data.sql
--updating for altered table "data" to values of "shipment_data" from the table "shipment"
--version 1.0
do language plpgsql $$
declare 
rec_shipment_data RECORD ;
shipment_date timestamp without time zone ; 
row_count integer ;
total_rows integer ;
begin

  select count(*) into total_rows from shipment ; 
  RAISE NOTICE 'Total %',total_rows;
  row_count:= 0 ;

  FOR rec_shipment_data IN SELECT * FROM shipment LOOP

   update data set "SHIPMENT_DATE" = rec_shipment_data."SHIPMENT_DATE" where "SHIPMENT_ID" = rec_shipment_data."SHIPMENT_ID";
   
   row_count:=  row_count +1 ;
   RAISE NOTICE 'row count = % , from %',row_count,total_rows;
  END LOOP;

end
$$;

Arbedwch dymp o'r tabl “data”.

pg_dump postgres --file=/dump/data.dmp --format=c --table=data --verbose > /dump/data.log 2>&1</source

Ail-greu'r tabl rhanedig “data”

--create_partition_data.sql
--create partitions for the table "wafer data" by range column "shipment_data" with one month duration
--version 1.0
do language plpgsql $$
declare 
rec_shipment_date RECORD ;
partition_name varchar;
index_name varchar;
current_year varchar ;
current_month varchar ;
begin_year varchar ;
begin_month varchar ;
next_year varchar ;
next_month varchar ;
first_flag boolean ;
i integer ;

begin

  RAISE NOTICE 'CREATE TEMPORARY TABLE FOR SHIPMENT_DATE';
  CREATE TEMP TABLE tmp_shipment_date as select distinct "SHIPMENT_DATE" from shipment order by "SHIPMENT_DATE" ;


  RAISE NOTICE 'DROP TABLE data';
  drop table data cascade ;


  RAISE NOTICE 'CREATE PARTITIONED TABLE data';
  
  CREATE TABLE public.data
  (
    "RUN_ID" integer,
    "LASERMARK" character varying(20) COLLATE pg_catalog."default" NOT NULL,
    "LOTID" character varying(80) COLLATE pg_catalog."default",
    "SHIPMENT_ID" integer NOT NULL,
    "PARAMETER_ID" integer NOT NULL,
    "INTERNAL_VALUE" character varying(75) COLLATE pg_catalog."default",
    "REPORTED_VALUE" character varying(75) COLLATE pg_catalog."default",
    "LOWER_SPEC_LIMIT" numeric,
    "UPPER_SPEC_LIMIT" numeric , 
    "SHIPMENT_DATE" timestamp without time zone
  )
  PARTITION BY RANGE ("SHIPMENT_DATE")
  WITH (
    OIDS = FALSE
  )
  TABLESPACE pg_default ;


  RAISE NOTICE 'CREATE PARTITIONS FOR TABLE data';

  current_year:='0';
  current_month:='0';

  begin_year := '0' ;
  begin_month := '0'  ;
  next_year := '0' ;
  next_month := '0'  ;
  i := 1;

  FOR rec_shipment_date IN SELECT * FROM tmp_shipment_date LOOP
      
      RAISE NOTICE 'SHIPMENT_DATE=%',rec_shipment_date."SHIPMENT_DATE";
      
      current_year := date_part('year' ,rec_shipment_date."SHIPMENT_DATE");
      current_month := date_part('month' ,rec_shipment_date."SHIPMENT_DATE") ; 

      --Init borders
      IF   begin_year = '0' THEN
       RAISE NOTICE '***Init borders';
       first_flag := true ; --first time flag
       begin_year := current_year ;
       begin_month := current_month ;   
   
        IF current_month = '12' THEN
          next_year := date_part('year' ,rec_shipment_date."SHIPMENT_DATE" + interval '1 year') ;
        ELSE
          next_year := current_year ;
        END IF;
     
       next_month := date_part('month' ,rec_shipment_date."SHIPMENT_DATE" + interval '1 month') ;

      END IF;

--      RAISE NOTICE 'current_year=% , current_month=% ',current_year,current_month;
--      RAISE NOTICE 'begin_year=% , begin_month=% ',begin_year,begin_month;
--      RAISE NOTICE 'next_year=% , next_month=% ',next_year,next_month;

      -- Check current date into borders NOT for First time

      RAISE NOTICE 'Current data = %',to_char( to_date( current_year||'.'||current_month, 'YYYY.MM'), 'YYYY.MM');
      RAISE NOTICE 'Begin data = %',to_char( to_date( begin_year||'.'||begin_month, 'YYYY.MM'), 'YYYY.MM');
      RAISE NOTICE 'Next data = %',to_char( to_date( next_year||'.'||next_month, 'YYYY.MM'), 'YYYY.MM');

      IF to_date( current_year||'.'||current_month, 'YYYY.MM') >= to_date( begin_year||'.'||begin_month, 'YYYY.MM') AND 
         to_date( current_year||'.'||current_month, 'YYYY.MM') < to_date( next_year||'.'||next_month, 'YYYY.MM') AND 
         NOT first_flag 
      THEN
         RAISE NOTICE '***CONTINUE';
         CONTINUE ; 
      ELSE
       --NEW borders only for second and after time 
       RAISE NOTICE '***NEW BORDERS';
       begin_year := current_year ;
       begin_month := current_month ;   
   
        IF current_month = '12' THEN
          next_year := date_part('year' ,rec_shipment_date."SHIPMENT_DATE" + interval '1 year') ;
        ELSE
          next_year := current_year ;
        END IF;
     
       next_month := date_part('month' ,rec_shipment_date."SHIPMENT_DATE" + interval '1 month') ;


      END IF;      

      IF to_number(current_month,'99') < 10 THEN
        current_month := '0'||current_month ; 
      END IF ;

      IF to_number(begin_month,'99') < 10 THEN
        begin_month := '0'||begin_month ; 
      END IF ;

      IF to_number(next_month,'99') < 10 THEN
        next_month := '0'||next_month ; 
      END IF ;

      RAISE NOTICE 'current_year=% , current_month=% ',current_year,current_month;
      RAISE NOTICE 'begin_year=% , begin_month=% ',begin_year,begin_month;
      RAISE NOTICE 'next_year=% , next_month=% ',next_year,next_month;

      partition_name := 'data_'||begin_year||begin_month||'01_'||next_year||next_month||'01'  ;

      RAISE NOTICE 'PARTITION NUMBER % , TABLE NAME =%',i , partition_name;
      
      EXECUTE format('CREATE TABLE ' || quote_ident(partition_name) || ' PARTITION OF data FOR VALUES FROM ( %L ) TO ( %L )  ' , begin_year||'-'||begin_month||'-01' , next_year||'-'||next_month||'-01'  ) ; 

      index_name := partition_name||'_shipment_id_parameter_id_idx';
      RAISE NOTICE 'INDEX NAME =%',index_name;
      EXECUTE format('CREATE INDEX ' || quote_ident(index_name) || ' ON '|| quote_ident(partition_name) ||' USING btree ("SHIPMENT_ID", "PARAMETER_ID") TABLESPACE pg_default ' ) ; 

      index_name := partition_name||'_lasermark_idx';
      RAISE NOTICE 'INDEX NAME =%',index_name;
      EXECUTE format('CREATE INDEX ' || quote_ident(index_name) || ' ON '|| quote_ident(partition_name) ||' USING btree ("LASERMARK" COLLATE pg_catalog."default") TABLESPACE pg_default ' ) ; 

      index_name := partition_name||'_shipment_id_idx';
      RAISE NOTICE 'INDEX NAME =%',index_name;
      EXECUTE format('CREATE INDEX ' || quote_ident(index_name) || ' ON '|| quote_ident(partition_name) ||' USING btree ("SHIPMENT_ID") TABLESPACE pg_default ' ) ; 

      index_name := partition_name||'_parameter_id_idx';
      RAISE NOTICE 'INDEX NAME =%',index_name;
      EXECUTE format('CREATE INDEX ' || quote_ident(index_name) || ' ON '|| quote_ident(partition_name) ||' USING btree ("PARAMETER_ID") TABLESPACE pg_default ' ) ; 

      index_name := partition_name||'_shipment_date_idx';
      RAISE NOTICE 'INDEX NAME =%',index_name;
      EXECUTE format('CREATE INDEX ' || quote_ident(index_name) || ' ON '|| quote_ident(partition_name) ||' USING btree ("SHIPMENT_DATE") TABLESPACE pg_default ' ) ; 

      --Drop first time flag
      first_flag := false ;

  END LOOP;
end
$$;

Llwythwch y dymp a grëwyd yng ngham 3.

pg_restore -h хост -юзер -d база --data-only --format=c --table=data --verbose  data.dmp > data_restore.log 2>&1

Creu adran ar wahân ar gyfer hen ddata

---------------------------------------------------
--create_partition_for_old_dates.sql
--create partitions for keeping old dates 
--version 1.0
do language plpgsql $$
declare 
rec_shipment_date RECORD ;
partition_name varchar;
index_name varchar;

begin

      SELECT min("SHIPMENT_DATE") AS min_date INTO rec_shipment_date from data ;

      RAISE NOTICE 'Old date is %',rec_shipment_date.min_date ;

      partition_name := 'data_old_dates'  ;

      RAISE NOTICE 'PARTITION NAME IS %',partition_name;

      EXECUTE format('CREATE TABLE ' || quote_ident(partition_name) || ' PARTITION OF data FOR VALUES FROM ( %L ) TO ( %L )  ' , '1900-01-01' , 
              to_char( rec_shipment_date.min_date,'YYYY')||'-'||to_char(rec_shipment_date.min_date,'MM')||'-01'  ) ; 

      index_name := partition_name||'_shipment_id_parameter_id_idx';
      EXECUTE format('CREATE INDEX ' || quote_ident(index_name) || ' ON '|| quote_ident(partition_name) ||' USING btree ("SHIPMENT_ID", "PARAMETER_ID") TABLESPACE pg_default ' ) ; 

      index_name := partition_name||'_lasermark_idx';
      EXECUTE format('CREATE INDEX ' || quote_ident(index_name) || ' ON '|| quote_ident(partition_name) ||' USING btree ("LASERMARK" COLLATE pg_catalog."default") TABLESPACE pg_default ' ) ; 

      index_name := partition_name||'_shipment_id_idx';
      EXECUTE format('CREATE INDEX ' || quote_ident(index_name) || ' ON '|| quote_ident(partition_name) ||' USING btree ("SHIPMENT_ID") TABLESPACE pg_default ' ) ; 

      index_name := partition_name||'_parameter_id_idx';
      EXECUTE format('CREATE INDEX ' || quote_ident(index_name) || ' ON '|| quote_ident(partition_name) ||' USING btree ("PARAMETER_ID") TABLESPACE pg_default ' ) ; 

      index_name := partition_name||'_shipment_date_idx';
      EXECUTE format('CREATE INDEX ' || quote_ident(index_name) || ' ON '|| quote_ident(partition_name) ||' USING btree ("SHIPMENT_DATE") TABLESPACE pg_default ' ) ; 

end
$$;

Canlyniadau terfynol:

Oedd
Cost: 502 997.55
Amser cyflawni: 505 eiliad.

Wedi dod yn
Cost: 68 533.70
Amser cyflawni: Eiliad 69

Teilwng, eithaf teilwng. Ac o ystyried ein bod ar hyd y ffordd wedi llwyddo i feistroli'r mecanwaith rhaniad yn PostgreSQL 10 fwy neu lai - canlyniad rhagorol.

Treuliad telynegol

A yw'n bosibl gwneud hyd yn oed yn well - OES, GALLWCH CHI!I wneud hyn mae angen i chi ddefnyddio VIEW MATERIALIZED.
CREATE MATERIALIZED VIEW LASERMARK_VIEW

CREATE MATERIALIZED VIEW LASERMARK_VIEW 
AS
SELECT w."LASERMARK" , MAX(s."SHIPMENT_DATE") AS "SHIPMENT_DATE"
FROM shipment s INNER JOIN data w ON s."SHIPMENT_ID" = w."SHIPMENT_ID" 
GROUP BY w."LASERMARK" ;

CREATE INDEX lasermark_vw_shipment_date_ind on lasermark_view USING btree ("SHIPMENT_DATE") TABLESPACE pg_default;
analyze lasermark_view ;

Unwaith eto rydym yn ailysgrifennu'r cais:
Ymholiad gan ddefnyddio golygfa wedi'i gwireddu

SELECT
            p."PARAMETER_ID" as  parameter_id,
            pc."PC_NAME" AS pc_name,
            pc."CUSTOMER_PARTNUMBER" AS customer_partnumber,
            w."LASERMARK" AS lasermark,
            w."LOTID" AS lotid,
            w."REPORTED_VALUE" AS reported_value,
            w."LOWER_SPEC_LIMIT" AS lower_spec_limit,
            w."UPPER_SPEC_LIMIT" AS upper_spec_limit,
            p."TYPE_CALCUL" AS type_calcul,
            s."SHIPMENT_NAME" AS shipment_name,
            s."SHIPMENT_DATE" AS shipment_date,
            extract(year from s."SHIPMENT_DATE") AS year,
            extract(month from s."SHIPMENT_DATE") as month,
            s."REPORT_NAME" AS report_name,
            p."STC_NAME" AS STC_name,
            p."CUSTOMERPARAM_NAME" AS customerparam_name
        FROM data w INNER JOIN shipment s ON s."SHIPMENT_ID" = w."SHIPMENT_ID"
             INNER JOIN parameters p ON p."PARAMETER_ID" = w."PARAMETER_ID"
             INNER JOIN shipment_pc sp ON s."SHIPMENT_ID" = sp."SHIPMENT_ID"
             INNER JOIN pc pc ON pc."PC_ID" = sp."PC_ID"
             INNER JOIN LASERMARK_VIEW md ON md."SHIPMENT_DATE" = s."SHIPMENT_DATE" AND md."LASERMARK" = w."LASERMARK"
        WHERE 
              s."SHIPMENT_DATE" >= '2018-07-01' AND s."SHIPMENT_DATE" <= '2018-09-30';

A chawn ganlyniad arall:
Oedd
Cost: 502 997.55
Amser cyflawni: 505 eiliad

Wedi dod yn
Cost: 42 481.16
Amser cyflawni: 43 eiliad.

Er, wrth gwrs, mae canlyniad mor addawol yn dwyllodrus; mae angen adnewyddu syniadau. Felly ni fydd cyfanswm yr amser i dderbyn data yn helpu llawer. Ond fel arbrawf mae'n eithaf diddorol.

A dweud y gwir, fel y digwyddodd, diolch eto asmm a Habru!- Gellir gwella'r ymholiad ymhellach.

Afterword

Felly, mae'r cwsmer yn fodlon. AC i manteisio ar y sefyllfa.

Tasg newydd: Beth allwch chi ei wneud i ddyfnhau ac ehangu?

Ac yna rwy'n cofio - bois, nid oes gennym ni fonitro ein cronfeydd data PostgreSQL.

Yn ymarferol, mae rhywfaint o fonitro o hyd ar ffurf Cloud Watch ar AWS. Ond beth yw budd y monitro hwn ar gyfer y DBA? Yn gyffredinol, bron dim.

Os cewch gyfle i wneud rhywbeth defnyddiol a diddorol drosoch eich hun, ni allwch fanteisio ar y cyfle hwn...
ER MWYN

Dyma sut rydyn ni'n dod at y rhan fwyaf diddorol:

Rhagfyr 3, 2018.
Gwneud penderfyniad i ddechrau ymchwil i'r galluoedd sydd ar gael ar gyfer monitro perfformiad ymholiadau PostgreSQL.

Ond stori hollol wahanol yw honno.

I'w barhau…

Ffynhonnell: hab.com

Parti Hapus neu cwpl o linellau-atgofion o gydnabod â rhaniad yn PostgreSQL10