database/basestore: add ScanFirstInt64
Created by: slimsag
Similar to ScanFirstInt
, but for int64 / Postgres bigint
. This will be used in a subsequent PR where I am counting (estimating) the number of rows in a potentially very large table (for API docs search) and we would otherwise quickly exceed the 2 billion max of a 32-bit integer.
Helps #21938
Signed-off-by: Stephen Gutekanst [email protected]