Subject | Why it's soo slow ? it's just a very simple select ... |
---|---|
Author | nathanelrick |
Post date | 2012-02-27T11:14:31Z |
hello,
the table :
CREATE TABLE DESCRIPTIONS
(
IDObj VARCHAR(15) NOT NULL,
type SMALLINT NOT NULL,
Lang VARCHAR(3) NOT NULL,
Descr VARCHAR(10000),
PRIMARY KEY (IDObj, type, Lang)
);
With around 40 millions records
now the query :
select Descr From DESCRIPTIONS where (IDObj='XXX') AND (type = 1)
=> 1200 ms to return only one reccord :(
the speed is the same if xxx not exist !
the plan used:
PLAN (DESCRIPTIONS INDEX (RDB$PRIMARY135))
what is wrong ?
on some other table with around the same number of rec but no VARCHAR(10000) field then the return is in around 40 ms !
the table :
CREATE TABLE DESCRIPTIONS
(
IDObj VARCHAR(15) NOT NULL,
type SMALLINT NOT NULL,
Lang VARCHAR(3) NOT NULL,
Descr VARCHAR(10000),
PRIMARY KEY (IDObj, type, Lang)
);
With around 40 millions records
now the query :
select Descr From DESCRIPTIONS where (IDObj='XXX') AND (type = 1)
=> 1200 ms to return only one reccord :(
the speed is the same if xxx not exist !
the plan used:
PLAN (DESCRIPTIONS INDEX (RDB$PRIMARY135))
what is wrong ?
on some other table with around the same number of rec but no VARCHAR(10000) field then the return is in around 40 ms !