Osquery uses basic SQL commands to leverage a relational data-model to describe a device.

osquery

yeah,I also find it in `flags.h`
```
#define OSQUERY_FLAG(t, n, v, d, s, e, c, h)                                   \
  DEFINE_##t(n, v, d);                                                         \
  namespace flags {                                                            \
  const int flag_##n = Flag::create(#n, {d, s, e, c, h});                      \
  }
....
#define HIDDEN_FLAG(t, n, v, d) OSQUERY_FLAG(t, n, v, d, 0, 0, 0, 1)
```