Sherehe ya Furaha au safu kadhaa za kumbukumbu juu ya kujua kugawa katika PostgreSQL10

Dibaji au jinsi wazo la kugawa lilivyotokea

Hadithi inaanzia hapa: Unakumbuka jinsi yote yalianza. Kila kitu kilikuwa kwa mara ya kwanza na tena. Baada ya karibu rasilimali zote za kuongeza ombi, wakati huo, zilikuwa zimechoka, swali liliibuka - nini baadaye? Hivi ndivyo wazo la kugawa lilivyoibuka.

Upungufu wa sauti:
Hasa 'wakati huo', kwa sababu kama ilivyotokea, kulikuwa na akiba ya uboreshaji ambayo haijatumika. Asante asmm na Habru!

Kwa hiyo, ni jinsi gani nyingine unaweza kufanya mteja furaha, na wakati huo huo kuboresha ujuzi wako mwenyewe?

Ili kurahisisha kila kitu iwezekanavyo, basi kuna njia mbili tu za kuboresha kwa kiasi kikubwa kitu katika utendaji wa hifadhidata:
1) Njia ya kina - tunaongeza rasilimali, kubadilisha usanidi;
2) Njia ya kina - uboreshaji wa hoja

Kwa kuwa, narudia, wakati huo haikuwa wazi tena ni nini kingine cha kubadilisha katika ombi la kuharakisha, njia ilichaguliwa - mabadiliko ya muundo wa meza.

Kwa hiyo, swali kuu linatokea: nini na jinsi gani tutabadilika?

Masharti ya awali

Kwanza, kuna ERD hii (iliyoonyeshwa kwa njia iliyorahisishwa kwa masharti):

Makala kuu:

1. mahusiano ya wengi kwa wengi
2. jedwali tayari lina ufunguo unaowezekana wa kugawa

Ombi la asili:

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' ;

Matokeo ya utekelezaji kwenye hifadhidata ya majaribio:
gharama : 502 997.55
Muda wa utekelezaji: Sekunde 505.

Tunaona nini? Ombi la kawaida, kulingana na kipande cha wakati.
Wacha tufanye dhana rahisi zaidi ya kimantiki: ikiwa kuna sampuli ya kipande cha wakati, itatusaidia? Hiyo ni kweli - kugawa.

Sehemu gani?

Kwa mtazamo wa kwanza, chaguo ni dhahiri - ugawaji tangazo wa jedwali la "usafirishaji" kwa kutumia kitufe cha "SHIPMENT_DATE" (kuruka mbele sana - mwishowe ikawa mbaya kidogo katika uzalishaji).

Jinsi ya kugawanya?

Swali hili pia si gumu sana. Kwa bahati nzuri, katika PostgreSQL 10, sasa kuna utaratibu wa kugawanya kwa wanadamu.
Hivyo:

1. Okoa utupaji wa jedwali la chanzo - pg_dump source_table
2. Futa meza asili - dondosha jedwali_jedwali la chanzo
3. Unda jedwali la mzazi na ugawaji wa anuwai - unda source_table ya jedwali
4. Unda sehemu - tengeneza source_table ya jedwali, tengeneza faharisi
5. Ingiza dampo iliyoundwa katika hatua ya 1 - pg_rejesha

Hati za kugawa

Kwa urahisi na urahisi, hatua 2,3,4 zimeunganishwa kuwa hati moja.

Hivyo:
Hifadhi utupaji wa jedwali la chanzo

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

Futa jedwali la chanzo + Unda jedwali kuu na ugawaji wa masafa + Unda sehemu

--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
$$;

Kuagiza dampo

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

Kuangalia matokeo ya kugawa

Tuna nini kama matokeo? Nakala kamili ya mpango wa utekelezaji ni kubwa na ya kuchosha, kwa hivyo inawezekana kabisa kujizuia kwa nambari za mwisho.

Ilikuwa

Gharama: 502 997.55
Muda wa utekelezaji: 505 sekunde.

Imekuwa

Gharama: 77 872.36
Muda wa utekelezaji: 79 sekunde.

Matokeo mazuri kabisa. Kupunguza gharama na muda wa utekelezaji. Kwa hivyo, utumiaji wa kugawa hutoa athari inayotarajiwa na, kwa ujumla, hakuna mshangao.

Mfurahishe mteja

Matokeo ya jaribio yaliwasilishwa kwa mteja kwa ukaguzi. Na baada ya kukagua, walipewa uamuzi ambao haukutarajiwa: "Nzuri, gawanya jedwali la "data".

Ndiyo, lakini tulikagua jedwali tofauti kabisa la "usafirishaji"; jedwali la "data" halina sehemu ya "SHIPMENT_DATE".

Hakuna shida, ongeza, badilisha. Jambo kuu ni kwamba mteja ameridhika na matokeo, maelezo ya utekelezaji sio muhimu sana.

Kugawanya meza kuu "data"

Kwa ujumla, hakuna matatizo fulani yaliyotokea. Ingawa, algorithm ya kugawa, kwa kweli, imebadilika kwa kiasi fulani.

Inaongeza safu wima ya "SHIPMENT_DATA" kwenye jedwali la "data".

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

Jaza maadili ya safu wima ya "SHIPMENT_DATA" kwenye jedwali la "data" na maadili ya safu wima ya jina moja kutoka kwa jedwali la "usafirishaji".

-----------------------------
--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
$$;

Hifadhi utupaji wa jedwali la "data".

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

Unda upya jedwali lililogawanywa "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
$$;

Pakia dampo lililoundwa katika hatua ya 3.

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

Unda sehemu tofauti kwa data ya zamani

---------------------------------------------------
--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
$$;

Matokeo ya mwisho:

Ilikuwa
Gharama: 502 997.55
Muda wa utekelezaji: Sekunde 505.

Imekuwa
Gharama: 68 533.70
Muda wa utekelezaji: 69 sekunde

Inastahili, inastahili kabisa. Na kwa kuzingatia kwamba njiani tuliweza kusimamia zaidi au chini ya utaratibu wa kugawa katika PostgreSQL 10 - matokeo bora.

Utapeli wa Lyrical

Je, inawezekana kufanya vizuri zaidi - NDIYO, UNAWEZA!Ili kufanya hivyo unahitaji kutumia MATERIALIZED VIEW.
UTANDA MTAZAMO UNAOFANYA 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 ;

Kwa mara nyingine tena tunaandika ombi tena:
Hoja kwa kutumia mwonekano wa kimaumbile

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';

Na tunapata matokeo mengine:
Ilikuwa
Gharama: 502 997.55
Muda wa utekelezaji: Sekunde 505

Imekuwa
Gharama: 42 481.16
Muda wa utekelezaji: 43 sekunde.

Ingawa, bila shaka, matokeo kama hayo ya kuahidi ni ya udanganyifu; mawazo yanahitaji kuburudishwa. Kwa hivyo muda wa jumla wa kupokea data hautasaidia sana. Lakini kama jaribio ni ya kuvutia sana.

Kwa kweli, kama ilivyotokea, asante tena asmm na Habru!- Hoja inaweza kuboreshwa zaidi.

Baada ya

Kwa hivyo, mteja ameridhika. NA unahitaji kuchukua fursa ya hali hiyo.

Jukumu jipya: Unaweza kuja na nini ili kukuza na kupanua?

Na kisha nakumbuka - jamani, hatuna ufuatiliaji wa hifadhidata zetu za PostgreSQL.

Kwa moyo mkunjufu, bado kuna ufuatiliaji katika mfumo wa Cloud Watch kwenye AWS. Lakini ni nini faida ya ufuatiliaji huu kwa DBA? Kwa ujumla, kivitendo hakuna.

Ikiwa una nafasi ya kufanya kitu muhimu na cha kuvutia kwako mwenyewe, huwezi kuchukua fursa hii ...
KWA



Hivi ndivyo tunavyofika sehemu ya kuvutia zaidi:

Desemba 3, 2018.
Kufanya uamuzi wa kuanza utafiti katika uwezo unaopatikana wa kufuatilia utendakazi wa hoja za PostgreSQL.

Lakini hiyo ni hadithi tofauti kabisa.

Itaendelea…

Chanzo: mapenzi.com