1. When using the SELECT statement, specify as many conditions for the (key) fields using the WHERE clause as possible.  It is important to keep the order of the fields used the same as in the table (or index), starting with the first key field.
2. Always specify your conditions in the WHERE (or LIKE) clause instead of checking them yourself with CHECK statements. The database system can then use an index (if possible) and the network load is considerably less.
3. When the full key is available code for the SELECT SINGLE statement. This method is the most efficient way of checking for existence of at least one valid selection if the complete primary key is provided otherwise the recommended alternative is using the UP TO 1 ROWS option.
4. Avoid using the SELECT…ENDSELECT.  Replace it with SELECT INTO an internal table.
5. Do not use the ORDER BY or GROUP BY, unless there is an index for the fields used.  Instead read into an internal table and sort / compute in the application server.
6. Be aware that complex WHERE conditions for pool and cluster tables usually cannot be passed to the database management system, therefore they are processed by the SAP database interface through post-selection.
7. If you want to find the maximum, minimum, sum, average value or the count of rows for a database column, use a select list with aggregate functions instead of computing the aggregates yourself.

Related Items:

• Accessing data in Packages
• Describe Select-Options
• Displaying an IDoc in a report
• Dynamic selection screen based
• Dynamic selection screens