Specifying class indexes from the Class Manager

The BMC Atrium CMDB Class Manager helps you index your classes. Indexing classes can reduce database query time. Index attributes that you expect users to query frequently, are used by discovery applications to identify Configuration Items (CIs), and are used in reconciliation identification rules. For more information about identification rules, see Creating an identification ruleset for reconciliation.

Creating or modifying classes process

Best practices for specifying or modifying class indexes

Specifying or modifying indexes in a class that already holds a large number of instances can take a significant amount of time and disk space. Therefore, avoid creating indexes during normal production hours. For more information about BMC Remedy AR System indexes, see  Defining indexes .

Before you begin

Ensure you have BMC Remedy Developer Studio installed. For more information, see  BMC Remedy Developer Studio .

To create a class index

1. Login to the computer where BMC Developer Studio is installed.

2. Open BMC Developer Studio.

3. Open the CMDB class form BMC:CORE:BMC_BaseElement, for example.

4. Switch to the Definitions tab at the bottom of the form window.
   

   The existing indexes and the fields used in the indexes are listed.

5. Click the New to create a new index.

To modify a class index

1. In the Class Manager, open a class for editing.
2. In the General tab of the CI Class or Relationship Class dialog box, expand the Indexes section.
3.  Click New.
4. In the Name field of the Index dialog box, enter a name for the new index.
5. Add at least one field to the index:
   1. Select one or more fields in the Fields on Form table. If you want to select multiple fields for a composite index, press the Ctrl key as you select fields.
   2. Click Add.
6. (optional) Specify indexing characteristics for the fields in the index:
   1.  In the Fields in Index table, select a field.
   2. If all values for the field must be unique, click the Unique check box.
   3.  If the index is the primary key for the class, click the Primary Key check box.
   4. Repeat step a through step c for the other fields in the Fields in Index table.
7.  In the Index dialog box, click OK.
8. Repeat step 3 through step 7 for other indexes you want to create for this class.
9. Perform one of the following actions:

Class indexes and attributes

If you create an index for a Character attribute, you can save query time by setting the QBE Match characteristic of that field to Leading or Equal instead of Anywhere.

Use the Indexes section on the General tab of the CI Class and Relationship Class dialog boxes to specify the indexes for a class. You can specify indexes on non-inherited attributes only. If an attribute is inherited form a superclass, you must specify the index for that attribute on the superclass. Display-only attributes cannot be indexed, because no values are stored for them.

To combine multiple attributes into a composite index, specify as many as 16 attributes per composite index. The sum of all attribute lengths in a single index must be fewer than or equal to 255 bytes, so Diary attributes and Character attributes larger than 255 bytes cannot be indexed.

More time is required to modify a class (for example, adding new attributes) when indexes have been specified for it. The greater the number of indexes specified for the class, the more time and disk space are required. Specifying and modifying instances also takes longer for classes with many indexes.