Jednou moznosti by bylo pouziti "materialized view". Asi by zalezelo na
konkretnich podminkach (jak casto pribyvaji zaznamy do prim. tabulky)...
CREATE MATERIALIZED VIEW mv_tabulka REFRESH FAST ON COMMIT
AS SELECT sum(sloupec) FROM tabulka
zdravi,
r.
Vilhelm, Robert wrote:
Dobry den,
Chtel bych se zeptat, jestli neexistuje najakym RYCHLY zpusobem
(tuning), jak ziskat pomoci SQL SUM, Sumu z tabluky citajici pres 30mil
zaznamu.
Jinimy slovy: zabranit pokazde full-table-scan.
PS: Pouziti funkcniho indexu neni mozne, kvuli agregacni funkci SUM.
Opravte me, jestli se mylim.
Dekuji
Robert Vilhelm
Zadani:
Pouzivam Oracle 9.2i
CREATE TABLE tabulka(
id NUMBER(18) NOT NULL,
sloupec NUMBER(18) NOT NULL,
CONSTRAINT tabulka_pk
PRIMARY KEY ( id )
);
"tabulka" ma pres 30mil zaznamu
SELECT SUM(sloupec)
FROM sloupec;
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