Very nice kata! From now going on I will be more attentive to how I write queries to make them more optimal!

The description isn't complete. The data schema of the "prospect" table is not fully specified - it has an "id" column that is not specified in the description.

Very nice kata! Though a lot of solutions are an overkill

The description isn't complete. The result table should be ordered by first_name and last_name.

So I've just googled how to improve query performance, and one thing that keeps coming up is creating an index for the table. don't know how to do that without running two queries though, which I can't do here.

I've always been terrible exercises like these.

it is possible, but the tests will not pass in all cases and not for all data. And since the data is generated dynamically, the complexity of sorting varies, as well as the correctness of the final sample.

I updated the description to address the additional requirements, and updated the tests to force a re-evaluation of currently accepted solutions which should now fail.

Not an issue, that's part of the challange:

Keep in mind that the agencies had access only to a partial customer base.

This would be nice if the kata description were more complete
Looking over the solutions, almost none are approaching production quality. You don't need regexes or some byzantine logic. The time available is easily adequate as your select should complete in << 1 second.
Real incoming data has Mr, Dr etc. in (as this has), with all sorts of separators from commas to slashes. Some at work includes 'MRS DR PROF' and such, sometimes as a prefix, sometimes as a suffix.

Must do Kata !! Don't skip for it.

I can't really tell what is wrong with this kata , but the dynamic data makes it really hard to troubleshoot my code. Data constantly changes in every trial, making it impossible for me to compare my results to the expected results. Plus, one of the requirements is about the expected number of rows (also changes in every trial). How can a kata be so speficific when dealing with messy text data, which contains problems that could be solved with a certain probability. Names are not meant to be used for %100 linkage.

Timed Out ERROR.

For those interested. Today I managed to complete this kata. The execution time was about 9000 ms. And recently one lucky man completed it in about 5000 ms.
So it is still posible to solve it but some optimization is required.