Configure BIND with database backend and DLZ support

Maybe be not really an answer to your question, but anyway. (I was also investigating this issue recently, and here's my conclusions):

DLZ support in BIND9 looks more like a "patch". It is not well documented - not a single word about it in BIND ARM. It seems to be not widely used. Query performance is terrible - according to this benchmark, PostgreSQL is going to be 30 times (!) slower than the normal in-memory operation. (the benchmark is old, but there's no reason to assume that things improved drastically).

I don't think it's a "most popular solution".

Other options:

BIND9 supports dynamic updates. It's well documented, widely used and is easy to implement. No performance penalty - all the queries still answered from memory. Setup is simplier as no database required. You perform updates programmatically using DNS protocol libraries (which probably exist for most languages, I myself use PHP) or via command line nsupdate tool. This is the solution I'd recommend.

If you really want database - PowerDNS seems to be designed to be used with database backend. It have features that may help not completely sacrifice the performance when using database, like it can cache database queries for some while instead of querying database each time. Some decent DNS hostings use PowerDNS.

More exotic option - BIND10, while still work in progress, yet developers claim that people actually use it in production. Currently BIND10 uses SQLITE backend.

For completeness, to address the original requirement ("dynamically update zone files without having to restart bind"): edit the zone file(s), send SIGHUP to named. The daemon will re-read the zone files.

It's a bit late, but I have made a tutorial here.

DLZ support is fully integrated into bind9, you just need to enable it when running ./configure.
It's not difficult, in fact, it's quite simple, but it's very badly documented.
My tutorial changes that.
Now it shouldn't take you longer than 30 minutes (including compilation time) to get it up and running.

Unfortunately, I can't copy the tutorial here, it's too large.