Checking the integrity of the links

Use the Link Integrity Check wizard to check the integrity of the link records for a database, that is, whether the data held for links is consistent with that held for the entity records at the ends of the links. You should check the integrity of the database schema before you check link integrity.

About this task

In a properly functioning database, the pages of the Link Integrity Check wizard should be empty. However, issues can occur and the wizard reports any problems found with links, or the entities they reference, and offers some repair options. Most repairs are safe and non-destructive, but some repairs might involve removing invalid data. You can use the list of proposed repairs to further inspect suspect data and perhaps recover it by other means. After repair, you should look at places where the wizard has added entities and links, possibly with blank mandatory fields, and decide how to make these records usable. Eventually, you must repair problems to avoid the possibility of misleading analysis based on faulty data.

Procedure

To use the Link Integrity Check wizard:

  1. Log on to the relevant security file as a database administrator but do not open the database.

  2. In iBase Designer, select Tools > Database Administration > Link Integrity Check. The Link Integrity Check wizard opens.

    Wizard Page

    Action

    Step 1

    Select a database from the list and click Next.

    Step 2

    Any link IDs listed on this page are missing one of the two link records that hold direction information. You can select list items to view more information that is displayed in the other panes on this page. All listed items are checked for repair by default, you can deselect any record that you do not want the wizard to repair.

    Step 3

    Any link IDs listed on this page are missing the description records that hold their link attributes. All checked items are repaired with blank data, which is the only possible repair. Deselect any record that you do not want the wizard to repair.

    Step 4

    Any link IDs listed on this page are missing both of the required records, and are selected by default to be deleted. This is the only repair available. You can choose to uncheck any link IDs that you do not want the wizard to delete, make a note of the details and fix the problem by other means.

    Step 5

    The entity IDs listed on this page cannot be found in the database, although they should be a link end record. The wizard can repair any missing entity records with blank data, which is the only possible repair.

    Step 6

    Links should only represent the relationship between two end records. Any link IDs listed here appear to connnect more than two ends, and cannot be repaired. Make a note of these issues for further investigation and fix the problem by other means.

    Step 7

    Any link IDs listed on this page have inconsistent record status values across the link ends table, and the link's own table. For consistency, the wizard addresses the problem by replacing the values in the link ends table with the value in the link table. All link IDs are checked for repair by default, they can be unchecked if required.

    Step 8

    You can review the list of fixes that you selected in the previous steps, and take the appropriate actions.

  3. Click:

    • Cancel To abandon all repairs.

    • Back If you want to select a different set of repairs in earlier pages of the wizard.

    • Finish To perform the listed repairs.

  4. Click Close. The database is opened, whether or not you asked for any repairs. What you do next depends on whether you repaired errors:

    • If the wizard did not report errors, the database is ready for use.

    • If the wizard reported errors and you chose to repair them, close the database and run the wizard again. (Some errors are only revealed after the wizard has made its first repairs.)

  5. Run the wizard again until you see no errors. After two uses with repairs performed, the third use of the wizard should always be error free.

What to do next

After repairs, you might need to add data for any records that are created with blank data fields or to replace removed entities or links, perhaps by importing data from a suitable source.