Progress
Basic Database
Tools
Schema>Index Editor
Choose Schema
Index Editor to define, rename, or delete indexes for the selected table. An index is a field or combination of fields Progress uses to rapidly retrieve a particular record in a table. A single index can be made up of multiple fields. For example, if you know you are always going to access the order-line table by using a combination of the Order-num and Line-num fields, you might want to create an index with those two fields as its components.
When you choose this option, Progress alphabetically lists all the tables defined for your database. When you select a table, a window similar to the one shown in Figure 9–14 appears.
Figure 9–14: Index Editor Window
NOTE: The current table must contain fields before you can define an index.Use the Index Editor to display the existing indexes and their information for the selected table.
The Index Editor window contains the following fields:
Name
Specifies the index name. It does not have to be the same name as the field name. Index names can be up to 32 character long and can consist of alphabetic characters, digits, and the characters $, &, #, %, –, and _. In addition, index names must begin with a letter (A–Z or a–z). You cannot use reserved Progress keywords as index names. Index names are not case sensitive.
Unique
Defines whether every entry in the index must be different. Enter yes if only one record in a table has a particular index value. For example, the customer table cannot contain two records with the same customer number, so customer number can be a unique index. Conversely, since many customers might be in the same sales region, sales-region should not be a unique index.
ACTIVE
Defines whether the index is initially active, that is, whether it updates itself every time a new record is created, deleted, or modified. If you are defining an index in a very large table, it is more efficient to define the index as initially inactive. (When an index is inactive, you cannot use it to retrieve or order records.) You can subsequently activate the index by running the PROUTIL utility with the IDXBUILD qualifier. This is much faster than building the index from within the Data Dictionary when the database contains a large amount of data. For more information about PROUTIL, see the Progress Database Administration Guide and Reference.
ROWID
For non-Progress databases only. See your Progress DataServer Guide for more information on the ROWID property.
Word
Defines whether you can search on any word within a field. A word index contains all the words from a text field or array of text fields; thus, you can search for records that contain specific words or phrases. All words in the field are index entries. For more information about word indexes, see the chapter on database access in the Progress Programming Handbook.
Seq
Defines the order in which fields form the index. For example, cust-order is a compound index, formed by the Cust-num and the Order-num fields. The Cust-num field has a sequence number of 1, and the Order-num field has a sequence number of 2.
Field Name
Displays the field name.
Type
Specifies the field data type. See the "Schema>Field Editor" section in this chapter for more information about data types.
Asc
Specifies that the index sorts records in ascending order.
Abbr
Specifies that you can search an index using the first few characters of a field without using the BEGINS phrase, if the field is a character data field. Indexes not comprised of character data require an exact match. If the index has more than one field, this setting applies only to the last field.
Table 9–16 describes the options for the Index Editor window.
Choose the field you want to edit, then choose a menu option. The following section describes the Add option in more detail.
Add Option
When you choose the Add option from the Index Editor, Progress prompts you for the name of the new index. When you enter data in the Name, Unique, Active, and Word fields and press RETURN, a window similar to the one shown in Figure 9–15 appears.
Figure 9–15: Index Add Option Window
![]()
Progress lists the available fields and their data types. When you choose a field, Progress prompts you to specify whether you want the index component to be ascending or descending. After you specify the sort order, Progress lets you choose more fields. You can specify up to 10 fields to define an index.
Progress lists the selected field above the divider line on the window. Select all your fields, then press GO. Progress prompts you to specify whether you want to use the Abbreviate option for character fields then returns you to the Index Editor and adds the new index to the list.
Copyright © 2004 Progress Software Corporation www.progress.com Voice: (781) 280-4000 Fax: (781) 280-4095 |