When comparing two Query operators or two states of one Query operator in Studio's EventFlow Compare Editor, you may see the following warning at the top of one side of the comparison:
This operator must be upgraded before the information on this tab
can be correctly displayed.
The Query operator's design changed in major ways at StreamBase release 7.2.0, in the number and names of tabs in its Properties view, and in the internal XML structure. Query operators created in releases before 7.2.0 are silently upgraded to the new format when opened, changed, and saved in the EventFlow Editor for 7.2.0 or later.
This message occurs when you try to compare a Query operator created in or upgraded to the 7.2 XML Query operator structure to an earlier version of the same operator, or to a similar Query operator, that is still in the XML format for a previous release. Because the underlying XML formats are so different, no meaningful comparison can be drawn in graphical form. This is especially true for comparisons of the Fallback tab, which did not exist before release 7.2.0.
Workarounds
There are two workarounds for this condition:
- Switch to Text Compare
-
Use the drop-down control just below the top pane of the Compare Editor to select Text Compare. This switches the attempted but failing graphical comparison to a side-by-side comparison of the underlying EventFlow XML. The two XML formats are different, but you may be able to locate the differences between the two states that are not due to XML format change, but are genuine Property setting differences.
- Save a Copy of the Older Version and Let it Upgrade
-
You may be able to save a copy of the older module of the two versions under comparison. Open, change, and save the copy in Studio 7.2 or later, then compare the two versions again.
Of course, you are not likely to want to change the actual historical version of a module stored in Eclipse local history or in your version control system. That would constitute changing the historical record and losing information. But if a graphical comparison of the two states is important, comparing an upgraded copy of the older version may still let you track down the exact Property setting differences you are seeking.