Nice post. I just want to point out that "handle them carefully" does not mean "check your indexes every day to make sure they're in sync with the database. It does not mean "make sure you run %BuildIndices() on a regular basis to make sure the indexes are in sync with the database." Applications, old or new, ensure that any updates to the data (insert, update, delete) are automatically reflected in the indexes.

"Handle them carefully" does mean, as Karthick points out:

• If you're running a query and you're not seeing data that you know is there, investigate whether the index is up to date. You can exclude the index like this: WHERE %NOINDEX Age = 26. If the missing records appear, you know that the index probably needs to be rebuilt. It would be good to investigate why the index got out of date, but that may be difficult. Which is why...
• ...rarely if ever manipulate the index globals directly, like this: "we accidentally deleted two entries from the index structure (not from the main table)."

COS? Creative ObjectScript? Comforting ObjectScript? Conventional ObjectScript? Contemplative ObjectScript? 😁🤣

@David Hockenbroch What about setting that variable (say tlevel) equal to the $TLEVEL at the start of the Try, and then in the Catch, only if $TLEVEL = (tlevel +1) (meaning only your TSTART happened), do a TROLLBACK 1? Because if $TLEVEL is >= 2 more than tlevel, it means that your Try called a method that started its own transaction and didn't correctly commit it or roll it back, and perhaps that method called another method that did the same thing, etc. I think coping with that in your Catch is not really your code's job. Do you concur?