Reset Table Auto Increment or Identity Columns

This topic explains possible impacts of XML Export/Import on table auto increment columns, and how to re-sequence the columns whose value approaches the maximum datatype value.




See also

XML Export/Import

XML Export/Import can cause gaps in the numbering sequence of auto increment columns.

Each XML Import deletes rows from several tables; the import then adds rows starting from the maximum value of the auto increment column.

Repeated XML imports can result in the value of the auto increment approaching the maximum value of the database datatype; for example, SQL Server's int datatype has a maximum value of 2,147,483,647.




Large auto increment values can also arise where the project originated as an EAP replica or design master.

The Jet engine assigns random values for auto increment columns with each XML Import into the project.

These random values can approach the maximum range of the repository data type, which could present a problem when the EAP project is transferred to a repository.



Access    Tools | Data Management | Reset IDs

How to

To re-sequence auto increment columns




Open the project.



Select the Reset IDs menu option.

A dialog displays listing all non-empty tables that contain an auto increment or identity column.

The Rows column shows the number of rows in the table
The Maximum ID column shows the current maximum value of the auto increment column
The Action column shows either No Action or Reset, depending on how close the column value is to the datatype's maximum


Tables requiring a reset are automatically selected in the list.



Click on the Go button to reset the auto increment column values.