Queue output items and reuse them.
Remove the unneeded type system in sql and just use the Go type system.
In best case this is more than an order of magnitude speedup:
```
BenchmarkSelectAll_1M-12 1 1841049400 ns/op 274299728 B/op 4198522 allocs/op
BenchmarkSelectAll_1M-12 14 84833400 ns/op 169228346 B/op 3146541 allocs/op
```
