Using the WITH REPLCHECK Keywords

Use the WITH REPLCHECK keywords to create the ifx_replcheck shadow column that Enterprise Replication uses for consistency checking.

The ifx_replcheck column is a visible shadow column because it can be indexed and can be viewed in system catalog tables. After you create the ifx_replcheck shadow column, you must create a new unique index on the primary key and the ifx_replcheck column. The ifx_replcheck shadow column must be the last column in the index. Enterprise Replication uses that index to speed consistency checking.

For most database operations, the ifx_replcheck column is hidden. For example, if you include the WITH REPLCHECK keywords when you create a table, the ifx_replcheck column has the following behavior:
  • It is not returned by queries that specify an asterisk ( * ) as the projection list, as in the statement:
    SELECT * FROM tablename;
  • It does appear in DB-Access when you ask for information about the columns of the table.
  • It is included in the number of columns (ncols) in the systables system catalog table entry for tablename.
To view the contents of the ifx_replcheck column, you must explicitly specify the columns in the projection list of a SELECT statement, as the following example shows:
SELECT ifx_replcheck FROM customer;

Example

In the following example, the ifx_replcheck shadow column is added to the customer table:

CREATE TABLE customer (id int) WITH REPLCHECK;

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