Specifies that synchronization should be download-only.

Syntax

ds={ ON | OFF }; ...

Remarks

When download-only synchronization occurs, dbmlsync does not upload any row operations or data. However, it does upload information about the schema and progress offset.

In addition, dbmlsync ensures that changes on the remote are not overwritten during download-only synchronization. It does this by scanning the log to detect rows with operations waiting to be uploaded. If any of these rows is modified by the download, the download is rolled back and the synchronization fails. If the synchronization fails for this reason, you must do a full synchronization to correct the problem.

When you have remotes that are synchronized by download-only synchronization, you should regularly do a full synchronization to reduce the amount of log that is scanned by the download-only synchronization. Otherwise, the download-only synchronizations take an increasingly long time to complete. If this is a problem, you can alternatively use a download-only publication to avoid log issues during synchronization.

For a list of the scripts that must be defined for download-only synchronization, see Required scripts.

The default is OFF (full synchronization of both upload and download).

This option has a short form and long form: you can use ds or DownloadOnly.

You can also store extended options in the database. For more information about dbmlsync extended options, see Introduction to dbmlsync extended options.

See also

• -ds option
• Download-only publications
• Upload-only and download-only synchronizations

Example

The following dbmlsync command line illustrates how you can set this option when you start dbmlsync:

dbmlsync -e "ds=on"

The following SQL statement illustrates how you can store this option in the database:

CREATE SYNCHRONIZATION SUBSCRIPTION
   TO sales_publication
   FOR ml_user1
   OPTION ds='ON';