To open the Rebuild dialog box:

1. Choose Utilities from the Command menu, then choose Rebuild from the cascading menu.

   The Rebuild dialog box opens.

2. Select a Rebuild option.

   For more information, see Rebuild Dialog Box and the individual procedures for each of the Rebuild options.

Choose Utilities from the Command menu, and Rebuild from the Utilities cascading menu to display the Rebuild dialog box. The Rebuild dialog box has the following fields and options:

• Rebuild a disorganized file

  This option can be used to perform the following functions:

  • Re-optimize a FOCUS data source after a large amount of data has been added or deleted.
  • Select specific segment instances to include in the data source, based on record selection criteria you specify.
• Index a field

  Builds or rebuilds the index for the specified field. Use this option to index an additional field that was not originally specified as an index field, or to change the index for a field. See Rebuilding the Index.

• Check the integrity of a file

  Checks the structural integrity of a data source. If FOCUS encounters an error during the check, it displays a message. See Checking the Integrity of a Data Source.

• Filename

  Contains the name of the data source to rebuild. Type a data source name in the Filename box, or click the Browse button to open a dialog box and select the data source.

• Selection Criteria

  Specifies selection criteria for rebuilding a disorganized data source and reorganizing a data source to fit a new Master File. Only data that meets the selection criteria is included in the rebuilt data source.

This option in the Rebuild dialog box enables you to:

• Restructure and optimize a FOCUS data source after data has been added or deleted.
• Select specific segment instances for inclusion in the data source based on selection criteria you supply. For example, if you specify the following selection criterion:

  INVOICE_DATE GT 990101

  FOCUS will omit invoices earlier than 99/01/01 from the rebuilt data source.

When you first create a Master File in the Synonym Editor, you specify the fields that you want indexed. Sometimes, after data is entered, you may need to index an additional field that was not originally specified as an index field.

The first step is to alter the Master File to indicate that the field should be indexed. Altering the Master File does not actually create the index. To do this, you must use the Rebuild utility after you index a field.

It is rare for the structural integrity of a FOCUS data source to be damaged. Structural damage will occasionally occur, however, during a disk drive failure or if an incorrect Master File is used. In this situation, you can check the integrity of the Master File. Checking the integrity of a Master File performs the following essential tasks:

• It checks all pointers in the data source.
• Should it encounter an error, it displays a message and attempts to branch around the offending segment or instance. In this way, it recovers as much of the data source as possible.

Although checking the integrity reports on a good deal of data that would otherwise be lost, it is important to remember that frequently backing up your FOCUS data sources is the best method of preventing data loss.

Checking the Master File integrity will occasionally fail to uncover structural damage. If you have reason to believe that there is damage to your data source, though results from checking the integrity indicates otherwise, there is a second method of checking file integrity. This method uses the ? FILE and TABLEF commands. For more information, see the Describing Data With WebFOCUS Language manual.