Exporting databases in XML and reloading after changes: a DeltaXML solution
An increasing number of databases and applications can now export data as XML. In many cases the purpose of this is to allow some form of editing or automated changes to be made before the data is saved back into the database or re-imported into an application.
In most cases, the first thing that needs be checked before the data is re-loaded is whether it has changed. If there is no change, then it does not need to be stored again. DeltaXML can help here to identify changes in an XML-aware way, so that unchanged data does not have to be stored again.
There is often a more stringent requirement which is to identify exactly what has changed so that the changes can be saved, thus avoiding saving a copy of the whole data set. This is especially the case when the original XML export file consists of an amalgamation of data from different objects or tables in a database. In this case, it really is much more efficient to find just the objects or rows that have changed and so update the database and avoid spurious duplication of a lot of other data. DeltaXML can take the hard work out of this task.
Because DeltaXML can identify changes to any XML data, you can use it to find the changes before re-loading the data. These changes are represented in XML, which means you can process these directly. For example, it would be possible to generate an SQL update script based on the changes to update the database.
The granularity of changes is often important. Sometimes it is not possible to modify part of an object, but the whole object needs to be replaced. An important advantage of using DeltaXML is that the granularity of the changes can be controlled. You can do this by generating the 'full delta' (changes and unchanged data in the delta file) and processing this to achieve the required level of granularity. XSLT provides one way to do this.
The ability to identify changes and represent these in a processable form provides new opportunities in the ETL (Extract Transform Load) and data warehouse industry. DeltaXML can handle large files (50Mb+) efficiently, making it suitable for handling large volumes of data.
We can provide assistance in determining the best XML structure for your data to ensure accurate identification of changes.
The data synchronization capabilities of DeltaXML also provide a new opportunity for XML data systems.