ONLINE HELP
 WINDEVWEBDEV AND WINDEV MOBILE

Help / WLanguage / Managing databases / HFSQL / Managing replications
  • Overview
  • Usage example of the data replication
  • Vocabulary specific to the replication
  • Databases
  • Type of replication
  • Files created during a replication
WINDEV
WindowsLinuxUniversal Windows 10 AppJavaReports and QueriesUser code (UMC)
WEBDEV
WindowsLinuxPHPWEBDEV - Browser code
WINDEV Mobile
AndroidAndroid Widget iPhone/iPadIOS WidgetApple WatchMac CatalystUniversal Windows 10 App
Others
Stored procedures
Replication: Available types
ODBCOLE DBNot available with these kinds of connection
Overview
The data replication is a powerful feature. The replication is the operation allowing the maintenance of remote databases with identical structures. Each one of these databases evolves independently: different operations are performed on these databases.
Via the replication, the operations performed on each one of the databases are applied to all the other databases.
WINDEV, WINDEV Mobile and WEBDEV allow you to easily perform these operations:
Summary table:
Log-based replicationUniversal replicationHFSQL server replication
HFSQL Classic database
X
X
HFSQL Client/Server database
X
X
Heterogeneous databases (HFSQL, Oracle, ...)
X

Usage example of the data replication

In a company, the "Customer" file must be accessible to all the salesmen, from their laptop computers as well as from the headquarters. Each salesman updates the file found on his laptop computer and gets regular updates from the main database of the company.
In an application that does not use the replication of data, the database is accessible by network in most cases. The salesman works via a modem connection to the network, with all the constraints regarding access time... Furthermore, all the users must be connected to the same network to access data.
With the replication, each one of the remote computers has its own database. This database (or replica) is identical to the "master" database during its initialization. Regularly, a "Synchronization" of these databases is used to take into account the modifications performed on each one of the different databases.
Vocabulary specific to the replication

Databases

The replication distinguishes between two types of databases:
  • The master database
    It is the reference database. All the updates are performed on this database:
    • modifications performed by the application run on this computer.
    • modifications performed on the remote computers and transmitted by the replication.
  • The replica database or subscriber database
    This remote database is identical to the "Master" database. The modifications performed by the remote computer are applied to this database. The replication transmits these modifications to the "master" database.

Type of replication

Two types of replication can be implemented:
  • Unidirectional replication
    This type of replication consists in performing an update from the "Master" database to the "Subscriber" databases or from a "Subscriber" database to the "Master" database.
  • Bidirectional replication
    This type of replication consists in performing an update from the "Master" database to the "Subscriber" databases and from the "Subscriber" databases to the "Master" database.

Files created during a replication

Several types of files specific to the replication are managed when the replication is implemented in a WINDEV application:
  • The master replica (RPM extension file): this file is associated with the master database. This file contains the names and identifiers of the different subscriber databases, as well as the date of the last synchronization.
  • The subscriber replica (RPL extension file): this file is associated with the subscriber database. This file contains the identifier of the subscriber database, the date of the last synchronization, ...
  • The movable replica (or movable media, .RPA file): this file is required to synchronize two remote databases that are not connected. The movable replica contains the information required to update the remote database. This file can be transmitted to the remote database via FTP, email or physical media.
Minimum version required
  • Version 10
This page is also available for…
Comments
Click [Add] to post a comment

Last update: 12/12/2023

Send a report | Local help