Mastering Table Comparison & Merging

Posted31 August 2023
byTristan Mitchell

What’s New in XML Merge 11.0.0 & DITA Merge 7.0.0

Last summer, we released XML Compare 12.0.0, which featured a new, improved algorithm for table comparison. This new approach leads to more precise, more intuitive and more detailed change representation in tables where one or more of the following changes have taken place:

Column span changes
Row span changes
Column order change
Row order change

It also adds the ability to ignore the order of columns, which means that a change in order doesn’t trigger delta markup in the result.

We’re excited to announce that with XML Merge 11.0.0 and DITA Merge 7.0.0, the new table algorithm is now available in our merge products as well.

Two-way table comparison is complicated enough, and extending that to n-way comparison has been a challenge! But we’re confident that this update will improve your merge results and make it easier to produce a single, resolved table merge if that’s your final output target.

Please note that we have kept both versions of the table processing in XML Merge 11. To use the new processing, you will need to enable it using the appropriate parameter settings. This allows you to test the new approach before using it in production.

The new table algorithm is currently only available in ConcurrentMerge.

How do we display structure changes?

If some of the table versions have different structures, we have to select a ‘master’ table from which to create the result. We use the Merge version priority to determine which version to use as the master. The spans in that version are prioritised, and other spans are created around them, sometimes as they were in the original and sometimes fragmented as necessary to ensure table validity. This approach helps to keep the result table as compact as possible while still representing how the table content has changed.

What do the new results look like?

The following examples demonstrate some of the improved results that the new table processing produces. The colouring in the screenshots is added to visualise the different versions and is based on the delta values in the XML result.

Examples

Use the tabs below to flick through how change between tables can now be shown depending on changes found.

Row span changes

Column span changes

Row and column span changes

Column addition changes

The “Column addition” example highlights one of the quirks of n-way table comparison: addition of the same column by different versions doesn’t always align. However, there is a simple fix – adding column keys will ensure that these align as expected. See our table documentation for more detail on how to achieve this. Column keying can also be used alongside unordered column comparison to ignore changes to column order.

We’d love to hear your feedback on the new table algorithm. Feedback is important for our ongoing product development and we read everything that we receive. So download or upgrade to the latest version of XML Merge today and give it a spin on your table content.