With the last update, I made a few significant modifications to the Merge Records tool, and I wanted to provide a bit more information around how these changes may or may not affect users. The changes can be broken down into two groups:
- User Defined Merge Field Support
- Multiple Record merge support
Prior to MarcEdit 6.1, the merge records tool utilized 4 different algorithms for doing record merges. These were broken down by field class, and as such, had specific functionality built around them since the limited scope of the data being evaluated, made it possible. Two of these specific functions was the ability for users to change the value in a field group class (say, change control numbers from 001 to 907$b) and the ability for the tool to merge multiple records in a merge file, into the source.
When I made the update to 6.1, I tossed out the 3 field specific algorithms, and standardized on a single processing algorithm – what I call the MARC21 option. This is an algorithm that processes data from a wide range of fields, and provides a high level of data evaluation – but in doing this, I set the fields that could be evaluated, and the function dropped the ability to merge multiple records into a single source file. The effect of this was that:
- Users could no longer change the fields/subfields used to evaluate data for merge outside of those fields set as part of the MARC21 option.
- if a user had a file that looked like the following —
sourcefile1 – record 1
mergefile – record1 (matches source1)
mergefile – record2
mergefile – record3 (matches source1)
Only data from the mergefile – record 1 would be merged. The tool didn’t see the secondary data that might be in the merge file. This has always been the case when working with the MARC21 merge option, but by making this the only option, I removed this functionality from the program (as the 3 custom field algorithms did make accommodations for merging data from multiple records into a single source).
With the last update, I’ve brought both of these to elements back to the tool. When a user utilizes the Merge Records tool, they can change the textbox with the field data – and enter a new field/subfield combination for matching (at this point, it must be a field/subfield combination). Secondly, the tool now handles the merging of multiple records if those data elements are matched via a title or control number. Since MarcEdit will treat user defined fields as the same class as a standard number (ISBN technically) for matching – users will now see that the tool can merge duplicate data into a single source file.
Questions about this – just let me know.