FBSimCity v0.4.0: the backup yard — gbak pins the OIT, nbackup fills the delta

FBSimCity &mdash; the explorable isometric city of Firebird internals &mdash; is at v0.4.0, and this release adds a whole backup yard, built around what gbak and nbackup actually do. gbak: the backup that pins your OIT gbak takes a logical backup online: it attaches like any other client and reads every table through a snapshot transaction. That snapshot is the interesting part &mdash; it pins