In sql, that would be select from tablex where property1=x and property2=y and so on. Or a join. But that tends to be slow-ish? Huh? It most definitely would

In sql, that would be select from tablex where property1=x and property2=y and so on. Or a join. But that tends to be slow-ish? Huh? It most definitely would not be the query you indicate-- that's a terrible, terrible way to store your data in this case. What you want is a join between the Item table and the Property table, and that should be lightning fast, if you have your indexes built properly. You neglect to say how many users you have, or how many concurrent queries you're expecting, or how quickly changing the data is, or what kind of hardware platform you're running on, so it is hard to talk about how easy/fast/scalable mysql would be. I'd suggest you just code a prototype using whatever database server you are most familiar with, and run some benchmarks to test the scaling.