Client: can you filter boats by location?
Me: Let me see... As you know, there are three remote systems that feed data into your database. I'd have to make a connection between the location records. But I can't rely on coordinates, name, ID or anything else. You'd have to manually create those links for me by remote systems records IDs. Telling me that record XY from system A is identical to record YX from system B, etc...
Client: How many records are we talking about?
Me: 504.

Three days later...

Client: Got it, is that enough for you in excel?
Me: Let me see... Very nice work, I can work with that.
Client: I almost died on it!

An hour later...

Me: Got it, test it and let's run it on the production version.
Client: It works beautifully.

A minute later...

Can we filter the ships by ports?
Me: Let me see... Yes, it's theoretically possible, but it's the same situation as with places...
Client: How many records are we talking about?
Me: 12,647.

Skype relayed to me the sound of something heavy falling, something grunting. Something dying.