hi select single

[Former Member]

hi

what is the actual diff between

select single and select up to 1 rows??

thanx

rocky

[Former Member]

hi

what is the actual diff between

select single and select up to 1 rows??

thanx

rocky

[Former Member]

Hello,

Please read these: , and .

Regards,

[Former Member]

Hi,

Select Single * will pickup only one matching record from the database into the buffer, and returns the same to the internal table.

Select upto 1 rows will pickup all the records matching the condition into the buffer, but return the top record to the internal table.

For this reason, performance wise select upto 1 row is better than select upto 1 row.

According to SAP Performance course the SELECT UP TO 1 ROWS is faster than SELECT SINGLE because you are not using all the primary key fields.

select single is a construct designed to read database records with primary key. In the absence of the primary key, it might end up doing a sequential search, whereas the select up to 1 rows may assume that there is no primary key supplied and will try to find most suitable index.

Cheers.

...Reward if useful.

[Former Member]

Hi,

When you use Select single, you must provide all key fields in the where clause, else it gives warning in extended check.

when you use "select up to 1 rows....endselect" it hits the database twice,,and hence slower compared to select single.

Please assign points

[Former Member]

HI,

select single * and select...upto 1 rows will both fetch one row.

but, select ...upto 1 rows need endselect and select single * doesn't need.

select single * is better performance wise.

rgds,

bharat.

[Former Member]

Hi,

According to SAP Performance course the SELECT UP TO 1 ROWS is faster than SELECT SINGLE because you are not using all the primary key fields.

select single is a construct designed to read database records with primary key. In the absence of the primary key, it might end up doing a sequential search, whereas the select up to 1 rows may assume that there is no primary key supplied and will try to find most suitable index.

The best way to find out is through sql trace or runtime analysis.

Use "select up to 1 rows" only if you are sure that all the records returned will have the same value for the field(s) you are interested in. If not, you will be reading only the first record which matches the criteria, but may be the second or the third record has the value you are looking for.

The System test result showed that the variant Single * takes less time than Up to 1 rows as there is an additional level for COUNT STOP KEY for SELECT ENDSELECT UP TO 1 ROWS.

The 'SELECT SINGLE' statement selects the first row in the database that it finds that fulfils the 'WHERE' clause If this results in multiple records then only the first one will be returned and therefore may not be unique.

Mainly: to read data from

The 'SELECT .... UP TO 1 ROWS' statement is subtly different. The database selects all of the relevant records that are defined by the WHERE clause, applies any aggregate, ordering or grouping functions to them and then returns the first record of the result set.

If satisfied,,Rewards me

Kind Regards

Yogesh

[Former Member]

Hi Rocky,

According to Performance course the SELECT UP TO 1 ROWS is faster than SELECT SINGLE because you are not using all the primary key fields.

The 'SELECT SINGLE' statement selects the first row in the database that it finds that fulfils the 'WHERE' clause If this results in multiple records then only the first one will be returned and therefore may not be unique.

Mainly: to read data from

The 'SELECT .... UP TO 1 ROWS' statement is different.The database selects all of the relevant records that are defined by the WHERE clause, applies any aggregate, ordering or grouping functions to them and then returns the first record of the result set.

Reward points if useful.

Cheers,

Swamy Kunche