{"id":31905,"date":"2019-10-31T21:43:52","date_gmt":"2019-10-31T18:43:52","guid":{"rendered":"https:\/\/prohoster.info\/blog\/happy-party-ili-para-strok-vospominanij-o-znakomstve-s-sektsionirovaniem-v-postgresql10\/"},"modified":"2019-10-31T21:43:52","modified_gmt":"2019-10-31T18:43:52","slug":"happy-party-ili-para-strok-vospominanij-o-znakomstve-s-sektsionirovaniem-v-postgresql10","status":"publish","type":"post","link":"https:\/\/prohoster.info\/it\/blog\/administrirovanie\/happy-party-ili-para-strok-vospominanij-o-znakomstve-s-sektsionirovaniem-v-postgresql10","title":{"rendered":"Happy Party o alcune righe di ricordi sulla suddivisione in PostgreSQL 10","gt_translate_keys":[{"key":"rendered","format":"text"}]},"content":{"rendered":"

Prefazione o come \u00e8 nata l'idea della partizionamento<\/h4>\n

\nL'inizio della storia qui: Ricordi come tutto \u00e8 iniziato. Era tutto nuovo e inedito.<\/a><\/noindex> Dopo aver esaurito quasi tutte le risorse per ottimizzare la query, a quel punto si \u00e8 posto il problema: e adesso cosa facciamo? Cos\u00ec \u00e8 nata l'idea del partizionamento. <\/p>\n

\"Happy
\n
\nUna digressione lirica:<\/b>
\nProprio 'in quel momento', perch\u00e9 come si \u00e8 scoperto, c'erano riserve di ottimizzazione non sfruttate<\/a><\/noindex>. Grazie asmm<\/a><\/noindex> e a Habr!<\/i><\/p>\n

Quindi, come possiamo rendere il cliente in qualche modo felice e al contempo migliorare le proprie competenze? <\/p>\n

Se semplifichiamo al massimo<\/b>, ci sono fondamentalmente solo due modi per migliorare radicalmente le prestazioni del database:
\n1) Approccio estensivo - aumentiamo le risorse, cambiamo la configurazione;
\n2) Approccio intensivo - ottimizzazione delle query<\/p>\n

Poich\u00e9, ripeto, a quel punto non era pi\u00f9 chiaro cosa modificare nella query per accelerare, si \u00e8 scelto di cambiare il design delle tabelle.<\/b><\/p>\n

Dunque, sorge la domanda principale: cosa e come cambieremo? <\/b>
\n<\/a><\/noindex><\/p>\n

Condizioni iniziali<\/h2>\n

\nInnanzitutto, abbiamo il seguente ERD (mostrato in modo schematico):
\n\"Happy
\nCaratteristiche principali:<\/p>\n

    \n
  1. relazioni 'molti a molti'<\/li>\n
  2. la tabella ha gi\u00e0 una potenziale chiave di partizionamento <\/li>\n<\/ol>\n

    Query iniziale:<\/p>\n

    SELECT\n            p.\"PARAMETER_ID\" as  parameter_id,\n            pc.\"PC_NAME\" AS pc_name,\n            pc.\"CUSTOMER_PARTNUMBER\" AS customer_partnumber,\n            w.\"LASERMARK\" AS lasermark,\n            w.\"LOTID\" AS lotid,\n            w.\"REPORTED_VALUE\" AS reported_value,\n            w.\"LOWER_SPEC_LIMIT\" AS lower_spec_limit,\n            w.\"UPPER_SPEC_LIMIT\" AS upper_spec_limit,\n            p.\"TYPE_CALCUL\" AS type_calcul,\n            s.\"SHIPMENT_NAME\" AS shipment_name,\n            s.\"SHIPMENT_DATE\" AS shipment_date,\n            extract(year from s.\"SHIPMENT_DATE\") AS year,\n            extract(month from s.\"SHIPMENT_DATE\") as month,\n            s.\"REPORT_NAME\" AS report_name,\n            p.\"SPARAM_NAME\" AS SPARAM_name,\n            p.\"CUSTOMERPARAM_NAME\" AS customerparam_name\n        FROM data w INNER JOIN shipment s ON s.\"SHIPMENT_ID\" = w.\"SHIPMENT_ID\"\n             INNER JOIN parameters p ON p.\"PARAMETER_ID\" = w.\"PARAMETER_ID\"\n             INNER JOIN shipment_pc sp ON s.\"SHIPMENT_ID\" = sp.\"SHIPMENT_ID\"\n             INNER JOIN pc pc ON pc.\"PC_ID\" = sp.\"PC_ID\"\n             INNER JOIN ( SELECT w2.\"LASERMARK\" , MAX(s2.\"SHIPMENT_DATE\") AS \"SHIPMENT_DATE\"\n                          FROM shipment s2 INNER JOIN data w2 ON s2.\"SHIPMENT_ID\" = w2.\"SHIPMENT_ID\" \n                          GROUP BY w2.\"LASERMARK\"\n                         ) md ON md.\"SHIPMENT_DATE\" = s.\"SHIPMENT_DATE\" AND md.\"LASERMARK\" = w.\"LASERMARK\"\n        WHERE \n             s.\"SHIPMENT_DATE\" >= '2018-07-01' AND s.\"SHIPMENT_DATE\" <= '2018-09-30' ;\n<\/code><\/pre>\n
    \nRisultati dell'esecuzione sul database di test:<\/b>
    \nCosto <\/b>: 502 997.55
    \nTempo di esecuzione<\/b>: 505 secondi.<\/p>\n
    Cosa vediamo? \u00c8 una query normale, su un intervallo temporale. 
    \nFacciamo un semplice presupposto logico: se c'\u00e8 un campione di intervallo temporale, ci aiuter\u00e0? Esatto - il partizionamento.<\/p>\n
    Cosa partizionare?<\/h2>\n
    \nA prima vista, la scelta \u00e8 ovvia - partizionamento dichiarativo della tabella 'shipment' per chiave 'SHIPMENT_DATE' (anticipando un po' - alla fine in produzione \u00e8 andata un po' diversamente<\/i>). <\/p>\n
    Come partizionare?<\/h2>\n
    \nQuesto quesito non \u00e8 neanche troppo complesso. Fortunatamente, in PostgreSQL 10, ora c'\u00e8 un meccanismo di partizionamento accessibile. 
    \nQuindi: <\/p>\n
      \n
    1.  Salviamo il dump della tabella originale - pg_dump source_table<\/i><\/li>\n
    2.  Eliminiamo la tabella originale - drop table source_table<\/i><\/li>\n
    3. Creiamo la tabella principale con partizionamento per intervallo - create table source_table<\/i><\/li>\n
    4.  Creiamo le sezioni - create table source_table, create index<\/i><\/li>\n
    5.  Importiamo il dump creato al passo 1 - pg_restore<\/i><\/li>\n<\/ol>\n
      <\/p>\n
      Script per il partizionamento <\/h2>\n
      \nPer semplicit\u00e0 e comodit\u00e0, i passaggi 2, 3, 4 sono stati uniti in un unico script. <\/p>\n
      Quindi: 
      \nSalviamo il dump della tabella originale<\/b><\/p>\n
      pg_dump postgres --file=\/dump\/shipment.dmp --format=c --table=shipment --verbose > \/dump\/shipment.log 2>&1<\/code><\/pre>\n
      \nEliminiamo la tabella originale + Creiamo la tabella principale con partizionamento per intervallo + Creiamo le sezioni<\/b><\/p>\n
      --create_partition_shipment.sql\ndo language plpgsql $$\ndeclare \nrec_shipment_date RECORD ;\npartition_name varchar;\nindex_name varchar;\ncurrent_year varchar ;\ncurrent_month varchar ;\nbegin_year varchar ;\nbegin_month varchar ;\nnext_year varchar ;\nnext_month varchar ;\nfirst_flag boolean ;\ni integer ;\nbegin\n  RAISE NOTICE 'CREA TABELLA TEMPORANEA PER SHIPMENT_DATE';\n  CREATE TEMP TABLE tmp_shipment_date as select distinct \"SHIPMENT_DATE\" from shipment order by \"SHIPMENT_DATE\" ;\n\n  RAISE NOTICE 'DROP TABLE shipment';\n  drop table shipment cascade ;\n  \n  CREATE TABLE public.shipment\n  (\n    \"SHIPMENT_ID\" integer NOT NULL DEFAULT nextval('shipment_shipment_id_seq'::regclass),\n    \"SHIPMENT_NAME\" character varying(30) COLLATE pg_catalog.\"default\",\n    \"SHIPMENT_DATE\" timestamp without time zone,\n    \"REPORT_NAME\" character varying(40) COLLATE pg_catalog.\"default\"\n  )\n  PARTITION BY RANGE (\"SHIPMENT_DATE\")\n  WITH (\n      OIDS = FALSE\n  )\n  TABLESPACE pg_default;\n\n  RAISE NOTICE 'CREA PARTIZIONI PER LA TABELLA shipment';\n\n  current_year:='0';\n  current_month:='0';\n\n  begin_year := '0' ;\n  begin_month := '0'  ;\n  next_year := '0' ;\n  next_month := '0'  ;\n\n  FOR rec_shipment_date IN SELECT * FROM tmp_shipment_date LOOP\n      \n      RAISE NOTICE 'SHIPMENT_DATE=%',rec_shipment_date.\"SHIPMENT_DATE\";\n      \n      current_year := date_part('year' ,rec_shipment_date.\"SHIPMENT_DATE\");\n      current_month := date_part('month' ,rec_shipment_date.\"SHIPMENT_DATE\") ; \n\n      IF to_number(current_month,'99') = to_date( begin_year||'.'||begin_month, 'YYYY.MM') AND \n         to_date( current_year||'.'||current_month, 'YYYY.MM') < to_date( next_year||'.'||next_month, 'YYYY.MM') AND \n         NOT first_flag \n      THEN\n         CONTINUE ; \n      ELSE\n       --NUOVI confini solo per la seconda e le volte successive \n       begin_year := current_year ;\n       begin_month := current_month ;   \n   \n        IF current_month = '12' THEN\n          next_year := date_part('year' ,rec_shipment_date."SHIPMENT_DATE" + interval '1 year') ;\n        ELSE\n          next_year := current_year ;\n        END IF;\n     \n       next_month := date_part('month' ,rec_shipment_date."SHIPMENT_DATE" + interval '1 month') ;\n\n      END IF;      \n\n      partition_name := 'shipment_shipment_date_'||begin_year||'-'||begin_month||'-01-'|| next_year||'-'||next_month||'-01'  ;\n \n     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'  ) ; \n\n      index_name := partition_name||'_shipment_id_idx';\n      RAISE NOTICE 'NOME INDICE =%',index_name;\n      EXECUTE format('CREATE INDEX ' || quote_ident(index_name) || ' ON '|| quote_ident(partition_name) ||' USING btree ("SHIPMENT_ID") TABLESPACE pg_default ' ) ; \n\n      --Drop first time flag\n      first_flag := false ;\n   \n  END LOOP;\n\nend\n$$;<\/code><\/pre>\n
      \nImportiamo il dump<\/b><\/p>\n
      pg_restore -d postgres --data-only --format=c --table=shipment --verbose  shipment.dmp > \/tmp\/data_dump\/shipment_restore.log 2>&1<\/code><\/pre>\n
      <\/p>\n
      Controlliamo i risultati della partizione<\/h2>\n
      \nCosa abbiamo come risultato? Il testo completo del piano di esecuzione \u00e8 lungo e noioso, quindi \u00e8 possibile limitarsi ai numeri finali.<\/p>\n
      C'era<\/h3>\n
      \nCosto:<\/b> 502 997.55
      \nTempo di esecuzione:<\/b> 505 secondi.<\/p>\n
      Diventato<\/h3>\n
      \nCosto:<\/b> 77 872.36
      \nTempo di esecuzione:<\/b> 79 secondi.<\/p>\n
      Un ottimo risultato. Abbiamo ridotto i costi e il tempo di esecuzione. In questo modo, l'utilizzo della partizione d\u00e0 l'effetto atteso e, in generale, senza sorprese. <\/p>\n
      Soddisfare il cliente<\/h2>\n
      \nI risultati del test sono stati presentati al cliente per la revisione. E dopo averli esaminati, \u00e8 stata emessa una sentenza piuttosto inaspettata: \u00abOttimo, partizionate la tabella \u00abdata\u00bb\u00bb.<\/p>\n
      S\u00ec, ma stiamo analizzando un'altra tabella, \u00abshipment\u00bb, la tabella \u00abdata\u00bb non ha il campo \u00abSHIPMENT_DATE\u00bb.<\/p>\n
      Nessun problema, aggiungete, cambiate. L'importante \u00e8 che il cliente sia soddisfatto del risultato, i dettagli dell'implementazione non sono particolarmente importanti.<\/p>\n
      Partizioniamo la tabella principale \u00abdata\u00bb<\/h2>\n
      \nIn effetti, non ci sono state particolari complessit\u00e0. Tuttavia, l'algoritmo di partizione \u00e8 cambiato un po'.<\/p>\n
      Aggiungiamo la colonna \u00abSHIPMENT_DATE\u00bb nella tabella \u00abdata\u00bb<\/b><\/p>\n
      psql -h host -U database -d user\n=> ALTER TABLE data ADD COLUMN \"SHIPMENT_DATE\" timestamp without time zone ;<\/code><\/pre>\n
      Compiliamo i valori della colonna \u00abSHIPMENT_DATE\u00bb nella tabella \u00abdata\u00bb con i valori della colonna omonima nella tabella \u00abshipment\u00bb<\/b><\/p>\n
      -----------------------------\n--update_data.sql\n--aggiornamento per la tabella \"data\" modificata ai valori di \"shipment_data\" dalla tabella \"shipment\"\n--version 1.0\ndo language plpgsql $$\ndeclare \nrec_shipment_data RECORD ;\nshipment_date timestamp without time zone ; \nrow_count integer ;\ntotal_rows integer ;\nbegin\n\n  select count(*) into total_rows from shipment ; \n  RAISE NOTICE 'Totale %',total_rows;\n  row_count:= 0 ;\n\n  FOR rec_shipment_data IN SELECT * FROM shipment LOOP\n\n   update data set \"SHIPMENT_DATE\" = rec_shipment_data.\"SHIPMENT_DATE\" where \"SHIPMENT_ID\" = rec_shipment_data.\"SHIPMENT_ID\";\n   \n   row_count:=  row_count +1 ;\n   RAISE NOTICE 'conteggio righe = % , da %',row_count,total_rows;\n  END LOOP;\n\nend\n$$;<\/code><\/pre>\n
      \nSalviamo il dump della tabella \u00abdata\u00bb<\/b><\/p>\n
      pg_dump postgres --file=\/dump\/data.dmp --format=c --table=data --verbose > \/dump\/data.log 2>&1<source<\/code><\/pre>\n
      Ricreiamo la tabella partizionata \u00abdata\u00bb<\/b><\/p>\n
      --create_partition_data.sql\n--crea partizioni per la tabella \"wafer data\" per intervallo nella colonna \"shipment_data\" con una durata di un mese\n--versione 1.0\ndo language plpgsql $$\ndeclare \nrec_shipment_date RECORD ;\npartition_name varchar;\nindex_name varchar;\ncurrent_year varchar ;\ncurrent_month varchar ;\nbegin_year varchar ;\nbegin_month varchar ;\nnext_year varchar ;\nnext_month varchar ;\nfirst_flag boolean ;\ni integer ;\n\nbegin\n\n  RAISE NOTICE 'CREA TABELLA TEMPORANEA PER SHIPMENT_DATE';\n  CREATE TEMP TABLE tmp_shipment_date as select distinct \"SHIPMENT_DATE\" from shipment order by \"SHIPMENT_DATE\" ;\n\n\n  RAISE NOTICE 'CANCELLA TABELLA data';\n  drop table data cascade ;\n\n\n  RAISE NOTICE 'CREA TABELLA PARTIZIONATA data';\n  \n  CREATE TABLE public.data\n  (\n    \"RUN_ID\" integer,\n    \"LASERMARK\" character varying(20) COLLATE pg_catalog.\"default\" NOT NULL,\n    \"LOTID\" character varying(80) COLLATE pg_catalog.\"default\",\n    \"SHIPMENT_ID\" integer NOT NULL,\n    \"PARAMETER_ID\" integer NOT NULL,\n    \"INTERNAL_VALUE\" character varying(75) COLLATE pg_catalog.\"default\",\n    \"REPORTED_VALUE\" character varying(75) COLLATE pg_catalog.\"default\",\n    \"LOWER_SPEC_LIMIT\" numeric,\n    \"UPPER_SPEC_LIMIT\" numeric , \n    \"SHIPMENT_DATE\" timestamp without time zone\n  )\n  PARTITION BY RANGE (\"SHIPMENT_DATE\")\n  WITH (\n    OIDS = FALSE\n  )\n  TABLESPACE pg_default ;\n\n\n  RAISE NOTICE 'CREA PARTIZIONI PER LA TABELLA data';\n\n  current_year:='0';\n  current_month:='0';\n\n  begin_year := '0' ;\n  begin_month := '0'  ;\n  next_year := '0' ;\n  next_month := '0'  ;\n  i := 1;\n\n  FOR rec_shipment_date IN SELECT * FROM tmp_shipment_date LOOP\n      \n      RAISE NOTICE 'SHIPMENT_DATE=%',rec_shipment_date.\"SHIPMENT_DATE\";\n      \n      current_year := date_part('year' ,rec_shipment_date.\"SHIPMENT_DATE\");\n      current_month := date_part('month' ,rec_shipment_date.\"SHIPMENT_DATE\") ; \n\n      --Inizializza i confini\n      IF   begin_year = '0' THEN\n       RAISE NOTICE '***Inizializza confini';\n       first_flag := true ; --flag primo giro\n       begin_year := current_year ;\n       begin_month := current_month ;   \n   \n        IF current_month = '12' THEN\n          next_year := date_part('year' ,rec_shipment_date.\"SHIPMENT_DATE\" + interval '1 year') ;\n        ELSE\n          next_year := current_year ;\n        END IF;\n     \n       next_month := date_part('month' ,rec_shipment_date.\"SHIPMENT_DATE\" + interval '1 month') ;\n\n      END IF;\n\n--      RAISE NOTICE 'current_year=% , current_month=% ',current_year,current_month;\n--      RAISE NOTICE 'begin_year=% , begin_month=% ',begin_year,begin_month;\n--      RAISE NOTICE 'next_year=% , next_month=% ',next_year,next_month;\n\n      -- Controlla la data corrente nei confini NON per il primo giro\n\n      RAISE NOTICE 'Dati correnti = %',to_char( to_date( current_year||'.'||current_month, 'YYYY.MM'), 'YYYY.MM');\n      RAISE NOTICE 'Dati iniziali = %',to_char( to_date( begin_year||'.'||begin_month, 'YYYY.MM'), 'YYYY.MM');\n      RAISE NOTICE 'Prossimi dati = %',to_char( to_date( next_year||'.'||next_month, 'YYYY.MM'), 'YYYY.MM');\n\n      IF to_date( current_year||'.'||current_month, 'YYYY.MM') >= to_date( begin_year||'.'||begin_month, 'YYYY.MM') AND \n         to_date( current_year||'.'||current_month, 'YYYY.MM') < to_date( next_year||'.'||next_month, 'YYYY.MM') AND \n         NOT first_flag \n      THEN\n         RAISE NOTICE '***CONTINUA';\n         CONTINUE ; \n      ELSE\n       --NUOVI confini solo per secondi e successivi giri \n       RAISE NOTICE '***NUOVI CONFINI';\n       begin_year := current_year ;\n       begin_month := current_month ;   \n   \n        IF current_month = '12' THEN\n          next_year := date_part('year' ,rec_shipment_date."SHIPMENT_DATE" + interval '1 year') ;\n        ELSE\n          next_year := current_year ;\n        END IF;\n     \n       next_month := date_part('month' ,rec_shipment_date."SHIPMENT_DATE" + interval '1 month') ;\n\n\n      END IF;      \n\n      IF to_number(current_month,'99') < 10 THEN\n        current_month := '0'||current_month ; \n      END IF ;\n\n      IF to_number(begin_month,'99') < 10 THEN\n        begin_month := '0'||begin_month ; \n      END IF ;\n\n      IF to_number(next_month,'99') < 10 THEN\n        next_month := '0'||next_month ; \n      END IF ;\n\n      RAISE NOTICE 'current_year=% , current_month=% ',current_year,current_month;\n      RAISE NOTICE 'begin_year=% , begin_month=% ',begin_year,begin_month;\n      RAISE NOTICE 'next_year=% , next_month=% ',next_year,next_month;\n\n      partition_name := 'data_'||begin_year||begin_month||'01_'||next_year||next_month||'01'  ;\n\n      RAISE NOTICE 'NUMERO PARTIZIONE % , NOME TABELLA =%',i , partition_name;\n      \n      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'  ) ; \n\n      index_name := partition_name||'_shipment_id_parameter_id_idx';\n      RAISE NOTICE 'NOME INDICE =%',index_name;\n      EXECUTE format('CREATE INDEX ' || quote_ident(index_name) || ' ON '|| quote_ident(partition_name) ||' USING btree ("SHIPMENT_ID", "PARAMETER_ID") TABLESPACE pg_default ' ) ; \n\n      index_name := partition_name||'_lasermark_idx';\n      RAISE NOTICE 'NOME INDICE =%',index_name;\n      EXECUTE format('CREATE INDEX ' || quote_ident(index_name) || ' ON '|| quote_ident(partition_name) ||' USING btree ("LASERMARK" COLLATE pg_catalog."default") TABLESPACE pg_default ' ) ; \n\n      index_name := partition_name||'_shipment_id_idx';\n      RAISE NOTICE 'NOME INDICE =%',index_name;\n      EXECUTE format('CREATE INDEX ' || quote_ident(index_name) || ' ON '|| quote_ident(partition_name) ||' USING btree ("SHIPMENT_ID") TABLESPACE pg_default ' ) ; \n\n      index_name := partition_name||'_parameter_id_idx';\n      RAISE NOTICE 'NOME INDICE =%',index_name;\n      EXECUTE format('CREATE INDEX ' || quote_ident(index_name) || ' ON '|| quote_ident(partition_name) ||' USING btree ("PARAMETER_ID") TABLESPACE pg_default ' ) ; \n\n      index_name := partition_name||'_shipment_date_idx';\n      RAISE NOTICE 'NOME INDICE =%',index_name;\n      EXECUTE format('CREATE INDEX ' || quote_ident(index_name) || ' ON '|| quote_ident(partition_name) ||' USING btree ("SHIPMENT_DATE") TABLESPACE pg_default ' ) ; \n\n      --Cancella flag primo giro\n      first_flag := false ;\n\n  END LOOP;\nend\n$$;\n<\/code><\/pre>\n
      \nCaricando il dump creato al passo 3.<\/b><\/p>\n
      pg_restore -h host -u user -d database --data-only --format=c --table=data --verbose data.dmp > data_restore.log 2>&1<\/code><\/pre>\n
      \nCreiamo una sezione separata per i dati vecchi<\/b><\/p>\n
      ---------------------------------------------------\n--create_partition_for_old_dates.sql\n--crea partizioni per mantenere date vecchie \n--versione 1.0\ndo language plpgsql $$\ndeclare \nrec_shipment_date RECORD ;\npartition_name varchar;\nindex_name varchar;\n\nbegin\n\n      SELECT min(\"SHIPMENT_DATE\") AS min_date INTO rec_shipment_date from data ;\n\n      RAISE NOTICE 'La data vecchia \u00e8 %',rec_shipment_date.min_date ;\n\n      partition_name := 'data_old_dates'  ;\n\n      RAISE NOTICE 'IL NOME DELLA PARTIZIONE \u00c8 %',partition_name;\n\n      EXECUTE format('CREATE TABLE ' || quote_ident(partition_name) || ' PARTITION OF data FOR VALUES FROM ( %L ) TO ( %L )  ' , '1900-01-01' , \n              to_char( rec_shipment_date.min_date,'YYYY')||'-'||to_char(rec_shipment_date.min_date,'MM')||'-01'  ) ; \n\n      index_name := partition_name||'_shipment_id_parameter_id_idx';\n      EXECUTE format('CREATE INDEX ' || quote_ident(index_name) || ' ON '|| quote_ident(partition_name) ||' USING btree (\"SHIPMENT_ID\", \"PARAMETER_ID\") TABLESPACE pg_default ' ) ; \n\n      index_name := partition_name||'_lasermark_idx';\n      EXECUTE format('CREATE INDEX ' || quote_ident(index_name) || ' ON '|| quote_ident(partition_name) ||' USING btree (\"LASERMARK\" COLLATE pg_catalog.\"default\") TABLESPACE pg_default ' ) ; \n\n      index_name := partition_name||'_shipment_id_idx';\n      EXECUTE format('CREATE INDEX ' || quote_ident(index_name) || ' ON '|| quote_ident(partition_name) ||' USING btree (\"SHIPMENT_ID\") TABLESPACE pg_default ' ) ; \n\n      index_name := partition_name||'_parameter_id_idx';\n      EXECUTE format('CREATE INDEX ' || quote_ident(index_name) || ' ON '|| quote_ident(partition_name) ||' USING btree (\"PARAMETER_ID\") TABLESPACE pg_default ' ) ; \n\n      index_name := partition_name||'_shipment_date_idx';\n      EXECUTE format('CREATE INDEX ' || quote_ident(index_name) || ' ON '|| quote_ident(partition_name) ||' USING btree (\"SHIPMENT_DATE\") TABLESPACE pg_default ' ) ; \n\nend\n$$;<\/code><\/pre>\n
      Risultati finali:<\/h3>\n
      \nC'era<\/b>
      \nCosto:<\/b> 502 997.55
      \nTempo di esecuzione<\/b>: 505 secondi.<\/p>\n
      Diventato<\/b>
      \nCosto:<\/b> 68 533.70
      \nTempo di esecuzione:<\/b> 69 secondi<\/p>\n
      Notevole, davvero notevole. E considerando che lungo il percorso ho potuto pi\u00f9 o meno apprendere il meccanismo di partizionamento in PostgreSQL 10 \u2014 Un ottimo risultato.<\/p>\n
      Divagazione lirica<\/h2>\n
      \nE si pu\u00f2 fare ancora meglio \u2014 S\u00cc, SI PU\u00d2!<\/b>Per fare ci\u00f2, \u00e8 necessario utilizzare una VIEW MATERIALIZZATA.
      \nCREATE MATERIALIZED VIEW LASERMARK_VIEW<\/b><\/p>\n
      CREATE MATERIALIZED VIEW LASERMARK_VIEW \nAS\nSELECT w.\"LASERMARK\" , MAX(s.\"SHIPMENT_DATE\") AS \"SHIPMENT_DATE\"\nFROM shipment s INNER JOIN data w ON s.\"SHIPMENT_ID\" = w.\"SHIPMENT_ID\" \nGROUP BY w.\"LASERMARK\" ;\n\nCREATE INDEX lasermark_vw_shipment_date_ind on lasermark_view USING btree (\"SHIPMENT_DATE\") TABLESPACE pg_default;\nanalyze lasermark_view ;\n<\/code><\/pre>\n
      \nAncora una volta riscriviamo la query:
      \nQuery con utilizzo della view materializzata<\/b><\/p>\n
      SELECT\n            p.\"PARAMETER_ID\" as  parameter_id,\n            pc.\"PC_NAME\" AS pc_name,\n            pc.\"CUSTOMER_PARTNUMBER\" AS customer_partnumber,\n            w.\"LASERMARK\" AS lasermark,\n            w.\"LOTID\" AS lotid,\n            w.\"REPORTED_VALUE\" AS reported_value,\n            w.\"LOWER_SPEC_LIMIT\" AS lower_spec_limit,\n            w.\"UPPER_SPEC_LIMIT\" AS upper_spec_limit,\n            p.\"TYPE_CALCUL\" AS type_calcul,\n            s.\"SHIPMENT_NAME\" AS shipment_name,\n            s.\"SHIPMENT_DATE\" AS shipment_date,\n            extract(year from s.\"SHIPMENT_DATE\") AS year,\n            extract(month from s.\"SHIPMENT_DATE\") as month,\n            s.\"REPORT_NAME\" AS report_name,\n            p.\"STC_NAME\" AS STC_name,\n            p.\"CUSTOMERPARAM_NAME\" AS customerparam_name\n        FROM data w INNER JOIN shipment s ON s.\"SHIPMENT_ID\" = w.\"SHIPMENT_ID\"\n             INNER JOIN parameters p ON p.\"PARAMETER_ID\" = w.\"PARAMETER_ID\"\n             INNER JOIN shipment_pc sp ON s.\"SHIPMENT_ID\" = sp.\"SHIPMENT_ID\"\n             INNER JOIN pc pc ON pc.\"PC_ID\" = sp.\"PC_ID\"\n             INNER JOIN LASERMARK_VIEW md ON md.\"SHIPMENT_DATE\" = s.\"SHIPMENT_DATE\" AND md.\"LASERMARK\" = w.\"LASERMARK\"\n        WHERE \n              s.\"SHIPMENT_DATE\" >= '2018-07-01' AND s.\"SHIPMENT_DATE\" <= '2018-09-30';\n<\/code><\/pre>\n
      \nE otteniamo un altro risultato:<\/b>
      \nC'era<\/b>
      \nCosto:<\/b> 502 997.55
      \nTempo di esecuzione<\/b>: 505 secondi<\/p>\n
      Diventato<\/b>
      \nCosto:<\/b> 42 481.16
      \nTempo di esecuzione:<\/b> 43 secondi.<\/p>\n
      Anche se, naturalmente, un risultato cos\u00ec promettente \u00e8 ingannevole, le view vanno rinfrescate. Quindi, il tempo finale per ottenere i dati non aiuter\u00e0 molto. Ma come esperimento \u00e8 piuttosto interessante.<\/p>\n
      In realt\u00e0, come si \u00e8 scoperto, un altro grazie asmm<\/a><\/noindex> e a Habr !- la query pu\u00f2 essere ancora migliorata. <\/a><\/noindex><\/p>\n
      Epifania<\/h2>\n
      \nQuindi, il cliente \u00e8 soddisfatto. E bisogno <\/b>sfruttare la situazione. <\/p>\n
      Nuova attivit\u00e0<\/b>: Cosa si pu\u00f2 inventare per approfondire e ampliare?<\/p>\n
      E qui mi ricordo \u2014 ragazzi, ma noi non abbiamo un monitoraggio dei nostri database PostgreSQL.<\/p>\n
      A dire il vero, c'\u00e8 un certo tipo di monitoraggio in Cloud Watch su AWS. Ma quale utilit\u00e0 ha questo monitoraggio per il DBA? Fondamentalmente, nessuna.<\/p>\n
      Se c'\u00e8 l'opportunit\u00e0 di fare qualcosa di utile e interessante anche per me, non posso lasciarmela sfuggire \u2026
      \nINFATTI
      \n<\/b>
      \n\"Happy
      \n
      \nCos\u00ec siamo arrivati al punto pi\u00f9 interessante:<\/p>\n
      3 Dicembre 2018.<\/b>
      \nDecisione di iniziare i lavori di ricerca per esplorare le possibilit\u00e0 di monitoraggio delle prestazioni delle query PostgreSQL.\n<\/p><\/blockquote>\n
      Ma questa \u00e8 una storia completamente diversa.<\/b><\/p>\n
      Continua, a seguire\u2026<\/i>
      \n
      Fonte:       habr.com<\/a><\/p>","protected":false,"gt_translate_keys":[{"key":"rendered","format":"html"}]},"excerpt":{"rendered":"
      \u041f\u0440\u0435\u0434\u0438\u0441\u043b\u043e\u0432\u0438\u0435 \u0438\u043b\u0438 \u043a\u0430\u043a \u0432\u043e\u0437\u043d\u0438\u043a\u043b\u0430 \u0438\u0434\u0435\u044f \u0441\u0435\u043a\u0446\u0438\u043e\u043d\u0438\u0440\u043e\u0432\u0430\u043d\u0438\u044f \u041d\u0430\u0447\u0430\u043b\u043e \u0438\u0441\u0442\u043e\u0440\u0438\u0438 \u0437\u0434\u0435\u0441\u044c: \u0422\u044b \u043f\u043e\u043c\u043d\u0438\u0448\u044c, \u043a\u0430\u043a \u0432\u0441\u0435 \u043d\u0430\u0447\u0438\u043d\u0430\u043b\u043e\u0441\u044c. \u0412\u0441\u0435 \u0431\u044b\u043b\u043e \u0432\u043f\u0435\u0440\u0432\u044b\u0435 \u0438 \u0432\u043d\u043e\u0432\u044c. \u041f\u043e\u0441\u043b\u0435 \u0442\u043e\u0433\u043e, \u043a\u0430\u043a \u043f\u043e\u0447\u0442\u0438 \u0432\u0441\u0435 \u0440\u0435\u0441\u0443\u0440\u0441\u044b \u0434\u043b\u044f \u043e\u043f\u0442\u0438\u043c\u0438\u0437\u0430\u0446\u0438\u0438 \u0437\u0430\u043f\u0440\u043e\u0441\u0430, \u043d\u0430 \u0442\u043e\u0442 \u043c\u043e\u043c\u0435\u043d\u0442, \u0431\u044b\u043b\u0438 \u0438\u0441\u0447\u0435\u0440\u043f\u0430\u043d\u044b, \u0432\u0441\u0442\u0430\u043b \u0432\u043e\u043f\u0440\u043e\u0441 \u2014 \u0430 \u0447\u0442\u043e \u0436\u0435 \u0434\u0430\u043b\u044c\u0448\u0435? \u0422\u0430\u043a \u0438 \u0432\u043e\u0437\u043d\u0438\u043a\u043b\u0430 \u0438\u0434\u0435\u044f \u043e \u0441\u0435\u043a\u0446\u0438\u043e\u043d\u0438\u0440\u043e\u0432\u0430\u043d\u0438\u0438. \u041b\u0438\u0440\u0438\u0447\u0435\u0441\u043a\u043e\u0435 \u043e\u0442\u0441\u0442\u0443\u043f\u043b\u0435\u043d\u0438\u0435: \u0418\u043c\u0435\u043d\u043d\u043e ‘\u043d\u0430 \u0442\u043e\u0442 \u043c\u043e\u043c\u0435\u043d\u0442’, \u043f\u043e\u0442\u043e\u043c\u0443, \u0447\u0442\u043e \u043a\u0430\u043a […]<\/p>\n","protected":false,"gt_translate_keys":[{"key":"rendered","format":"html"}]},"author":1,"featured_media":23765,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[688],"tags":[],"class_list":["post-31905","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-administrirovanie"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\n","aioseo_head_json":{"title":"\ud83e\udd47Happy Party o due righe di ricordi sulla scoperta del partizionamento in PostgreSQL10 | ProHoster","description":"Prefazione o come \u00e8 nata l'idea del partizionamento Inizio della storia qui: Ricordi come \u00e8 iniziato tutto. Era tutto nuovo e straordinario. Dopo che quasi tutte le risorse per ottimizzare la query erano esaurite, si \u00e8 posto il problema \u2014 e ora? Cos\u00ec \u00e8 nata l'idea del partizionamento. Un'osservazione lirica: Proprio 'in quel momento', perch\u00e9","canonical_url":"https:\/\/prohoster.info\/it\/blog\/administrirovanie\/happy-party-ili-para-strok-vospominanij-o-znakomstve-s-sektsionirovaniem-v-postgresql10","robots":"max-image-preview:large","keywords":"","webmasterTools":{"miscellaneous":""},"schema":null,"og:locale":"it_IT","og:site_name":"ProHoster | \u041a\u0443\u043f\u0438\u0442\u044c \u043d\u0430\u0434\u0435\u0436\u043d\u044b\u0439 \u0445\u043e\u0441\u0442\u0438\u043d\u0433 \u0434\u043b\u044f \u0441\u0430\u0439\u0442\u043e\u0432 \u0441 \u0437\u0430\u0449\u0438\u0442\u043e\u0439 \u043e\u0442 DDoS, VPS VDS \u0441\u0435\u0440\u0432\u0435\u0440\u044b","og:type":"article","og:title":"\ud83e\udd47Happy Party \u0438\u043b\u0438 \u043f\u0430\u0440\u0430 \u0441\u0442\u0440\u043e\u043a-\u0432\u043e\u0441\u043f\u043e\u043c\u0438\u043d\u0430\u043d\u0438\u0439 \u043e \u0437\u043d\u0430\u043a\u043e\u043c\u0441\u0442\u0432\u0435 \u0441 \u0441\u0435\u043a\u0446\u0438\u043e\u043d\u0438\u0440\u043e\u0432\u0430\u043d\u0438\u0435\u043c \u0432 PostgreSQL10 | ProHoster","og:description":"\u041f\u0440\u0435\u0434\u0438\u0441\u043b\u043e\u0432\u0438\u0435 \u0438\u043b\u0438 \u043a\u0430\u043a \u0432\u043e\u0437\u043d\u0438\u043a\u043b\u0430 \u0438\u0434\u0435\u044f \u0441\u0435\u043a\u0446\u0438\u043e\u043d\u0438\u0440\u043e\u0432\u0430\u043d\u0438\u044f \u041d\u0430\u0447\u0430\u043b\u043e \u0438\u0441\u0442\u043e\u0440\u0438\u0438 \u0437\u0434\u0435\u0441\u044c: \u0422\u044b \u043f\u043e\u043c\u043d\u0438\u0448\u044c, \u043a\u0430\u043a \u0432\u0441\u0435 \u043d\u0430\u0447\u0438\u043d\u0430\u043b\u043e\u0441\u044c. \u0412\u0441\u0435 \u0431\u044b\u043b\u043e \u0432\u043f\u0435\u0440\u0432\u044b\u0435 \u0438 \u0432\u043d\u043e\u0432\u044c. \u041f\u043e\u0441\u043b\u0435 \u0442\u043e\u0433\u043e, \u043a\u0430\u043a \u043f\u043e\u0447\u0442\u0438 \u0432\u0441\u0435 \u0440\u0435\u0441\u0443\u0440\u0441\u044b \u0434\u043b\u044f \u043e\u043f\u0442\u0438\u043c\u0438\u0437\u0430\u0446\u0438\u0438 \u0437\u0430\u043f\u0440\u043e\u0441\u0430, \u043d\u0430 \u0442\u043e\u0442 \u043c\u043e\u043c\u0435\u043d\u0442, \u0431\u044b\u043b\u0438 \u0438\u0441\u0447\u0435\u0440\u043f\u0430\u043d\u044b, \u0432\u0441\u0442\u0430\u043b \u0432\u043e\u043f\u0440\u043e\u0441 \u2014 \u0430 \u0447\u0442\u043e \u0436\u0435 \u0434\u0430\u043b\u044c\u0448\u0435? 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