## Checking Database Structures

You can use the Database Manager GUI to check whether the database structures of a database instance are consistent. The length and ascending order of the keys are checked, among other things.

We recommend that you check the database structures once a week.

This check is extremely CPU intensive and time consuming because many I/O operations have to be carried out. Plan checks in the production system only for times when the load on the database system is reduced or carry out the check on a database copy (see Concepts of the Database System, Database Copy).

### Prerequisites

The database instance is in the ONLINE or ADMIN operational state.

### Procedure

...

1. Select the required database instance in the list of database instances.
Connect to the DBM server for this database instance if necessary.

2. Choose Instance ® Check ® Database Structure.

3. Choose the required function and specify the relevant options in the following step.

Functions and Options for Checking the Database Structure

Function | Operational State | Command | Options
Checking the entire dataset | ONLINE | Check database structure in operational state ONLINE | EXCEPT INDEX: Indexes are not checked. This option usually speeds up the check.
Checking the entire dataset and cleaning the converter | ADMIN | Check database structure and clear converter in operation state ADMIN |

Checking a selected table

ONLINE

Check database structure for a selected table in operational state ONLINE

WITH LONG CHECK: If the base table to be checked contains LONG columns, the system checks whether all the LONG values defined actually exist. To ensure the consistency of the transaction, an SQL share lock is requested for the duration of the check.

CATALOG: The database catalog for this table is checked. This option cannot be combined with the EXTENDED and WITH LONG CHECK options.

4. To start the database structure check, choose Start.

5. After the check has been completed, choose Close.

### Result

Errors encountered during the database structure check are written to the Database Errors log file. You can open this file to analyze these errors (see Reading Log Files).

See also:

Concepts of the Database System, Checking Database Structures