compute {dplyr} | R Documentation |
compute
forces computation of lazy tbls, leaving data in the remote
source. collect
also forces computation, but will bring data back into
an R data.frame (stored in a tbl_df
). collapse
doesn't
force computation, but collapses a complex tbl into a form that additional
restrictions can be placed on.
compute(x, name = random_table_name(), ...) collect(x, ...) collapse(x, ...) ## S3 method for class 'tbl_sql' compute(x, name = random_table_name(), temporary = TRUE, unique_indexes = list(), indexes = list(), ...)
x |
a data tbl |
name |
name of temporary table on database. |
... |
other arguments passed on to methods |
temporary |
if |
unique_indexes |
a list of character vectors. Each element of the list will create a new unique index over the specified column(s). Duplicate rows will result in failure. |
indexes |
a list of character vectors. Each element of the list will create a new index. |
compute
and collect
preserve grouping, collapse
drops
it.
copy_to
which is the conceptual opposite: it
takes a local data frame and makes it available to the remote source.
if (require("RSQLite") && has_lahman("sqlite")) { batting <- tbl(lahman_sqlite(), "Batting") remote <- select(filter(batting, yearID > 2010 && stint == 1), playerID:H) remote2 <- collapse(remote) cached <- compute(remote) local <- collect(remote) }