Synchronizing databases

What is synchronization?

SQL Remote replication is carried out using the information in the transaction log, but there are two circumstances where SQL Remote deletes all existing rows from those tables of a remote database that form part of a publication, and copies the publication's entire contents from the consolidated database to the remote site. This process is called synchronization.

When to synchronize

Synchronization is used under the following circumstances:

  • When a subscription is created at a consolidated database a synchronization is carried out, so that the remote database starts off with a database in the same state as the consolidated database.
  • If a remote database gets corrupt or gets out of step with the consolidated database, and cannot be repaired using SQL passthrough mode, synchronization forces the remote site database back in step with the consolidated site.
How to synchronize

Synchronizing a remote database can be done in the following ways:

  • Use the database Extraction utility   This utility creates a schema for a remote SQL Anywhere database, and synchronizes the remote database. This is generally the recommended procedure.

  • Manual synchronization   Synchronize the remote database manually by loading from files, using the PowerBuilder pipeline, or some other tool.

  • Synchronize over the message system   Synchronize the remote database via the message system using the SYNCHRONIZE SUBSCRIPTION statement.

    Caution

    Do not execute SYNCHRONIZE SUBSCRIPTION at a remote database.

Mixed operating systems and database extraction
Notes on synchronization and extraction

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