Performance of SELECT Statements

[Former Member]

Hi All,

I have a small confusion.

Consider these 3 statements :

A.

SELECT * from table1 where {conditions based on primary key}.

exit.

Endselect.

B.

SELECT SINGLE * from table1 where {conditions based on primary key}.

C.

SELECT upto 1 rows from table1 where {conditions based on primary key}.

Considering that table1 has more than 1 primary keys,Which statement gives the best peformance when

1.All the keys are used in the where condition.

2.Only a few keys are used in the where condition

Thanks in advance.

Hari

[Former Member]

for all conditions option B gives the best performance.

[Former Member]

Hi,

If you are interested in only one record then

1.All the keys are used in the where condition.

Ans B

2.Only a few keys are used in the where condition

Ans C

santhosh

[Former Member]

hi

in all cases option B will give best performance.

first option will give very poor performance

(checked)

[valter_oliveira]

In situation 1 it's definitly B. In situation 2 I would say "a mix of C and A", like:

SELECT field1 ... fieldn from table1 UP TO 1 ROWS where {conditions based on primary key}.

exit.

Endselect.

Regards,

Valter Oliveira.