Hierarchy
SAP_ABA (Software Component) Cross-Application Component⤷
AP-MD-BP (Application Component) SAP Business Partner⤷
BUPA (Package) SAP Business Partner
Basic Data
| Data Element | BU_SELECTIVITY |
| Short Description | BDT search help: Selectivity of a search field |
Data Type
| Category of Dictionary Type | D | Domain |
| Type of Object Referenced | No Information | |
| Domain / Name of Reference Type | NUMC2 | |
| Data Type | NUMC | Character string with only digits |
| Length | 2 | |
| Decimal Places | 0 | |
| Output Length | 2 | |
| Value Table |
Further Characteristics
| Search Help: Name | ||
| Search Help: Parameters | ||
| Parameter ID | ||
| Default Component name | ||
| Change document | ||
| No Input History | ||
| Basic direction is set to LTR | ||
| No BIDI Filtering |
Field Label
| Length | Field Label | |
| Short | 5 | Sel. |
| Medium | 15 | Selectivity |
| Long | 20 | Selectivity |
| Heading | 15 | Selectivity |
Documentation
Definition
The selectivity of a table field is the number of different entries this field has in a table. However, you do not enter the absolute, but rather the relative selectivity. Permitted values range between 1 and 10, with 1 being the highest selectivity level and 10 the lowest. In a table with personal data, you would assign the ID card number field a selectivity level of 1 and the sex field a level of 10.
You only have to specify selectivity for fields that have an index.
If one index covers several fields, you have to specify the total selectivity of fields 1 to n together and not the selectivity of the field alone for a field starting at position n (see example).
Because several fields together are more selective than one field alone, the selectivity key figures must decrease in an index which has increasing position numbers.
Example
Bank details for business partners are stored in a table. The index BNK can be found using the fields bank number, account number and bank country. You would want to specify selectivity as follows:
Field name Index name Pos. in index Selectivity
Bank number BNK 1 7
Account no. BNK 2 2
Bank country BNK 3 1
The bank number alone is not very selective (sel. 7), bank number and account number together highly selective (sel. 2), bank number, account number and bank country together are able to identify a business partner (sel. 1).
Use
To retrieve the necessary data, the BDT search program generally has to access several tables and/or views. The first table or view to be selected decides the speed of the search. In order to make this decision, the program requires the following information:
- For which fields in which tables are there selection conditions?
- Which fields have indexes?
- Which of these fields has the greatest selectivity?
Example
You are looking for a business partner by name and telephone number. Each field is in a different table and each has an index. The table selected first decides the selectivity of the fields. Because the telephone number is more selective than the name, the table with the telephone number is selected first.
Notes
Incorrect selectivity specifications can slow down a search considerably.
History
| Last changed by/on | SAP | 20010216 |
| SAP Release Created in |
