Have default project?

[hadley]

Have default project?

[krlmlr]

Why not using an R option for this?

query_exec <- function(query, project = getOption("bigrquery.project"), ...,
                       default_dataset = getOption("bigrquery.dataset"), ...)

[hadley]

I think it's a bad idea to use options to change the computation of a function because it leads to highly non-local behaviour (using them to affect output display, OTOH, is fine)

[hadley]

This may be less important with the DBI interface. We'll see

[byapparov]

It probably would be better to take r out of the middle in the variable name, e.g.:

BIGQUERY_PROJECT
BIGQUERY_DATASET

(unless there is a known clash of names)