Max Berger

Personal information and more...
  • Home
  • Research
  • Teaching
  • OpenSource
  • HOWTOs
  • Security
  • Blog

Home

Research

  • Bibliography

  • SILENUS

  • SyncML

Chapter 6. Synchronization basics
Prev Part II. Synchronization concepts Next

Chapter 6. Synchronization basics

Table of Contents

What is synchronization?
Database operations
Soft deletion and hard deletion
Disconnected operation
Unique identifiers
Transaction logs
Regular sync
Slow sync
One-way sync

Basic research is what I am doing when I don't know what I am doing.

--Wernher von Braun

Before we can start creating synchronization applications, we have to take a look at certain synchronization concepts first. And even before that we need to find out what is meant by synchronziation.

What is synchronization?

We define two databases as synchronized whenever their contents are equivalent. Whenever their contents are not equivalent, the databases are unsynchronized or out of sync. It is important to note that equivalent does not necessary mean exactly equal.

Having said that, how do we get two databases to be synchronized and how do they get out of sync?

The easiest way of synchronizing two databases is by replication. With replication the master database is simply copied over the content of the client database. After that process, the former client data is lost, but both databases have the same content.

Databases get out of sync, when at least one database operation is applied to one database and not the other.


Prev Up Next
Part II. Synchronization concepts Home Database operations
Content copyright Jun 2018 by Max Berger Design: TEMPLATED Images: Unsplash (CC0) Privacy Policy