Force computation of a database query
compute() stores results in a remote temporary table.
collect() retrieves data into a local tibble.
collapse() is slightly different: it doesn't force computation, but
instead forces generation of the SQL query. This is sometimes needed to work
around bugs in dplyr's SQL generation.
All functions preserve grouping and ordering.
compute(x, ...) collect(x, ...) collapse(x, ...)
x |
A data frame, data frame extension (e.g. a tibble), or a lazy data frame (e.g. from dbplyr or dtplyr). See Methods, below, for more details. |
... |
Arguments passed on to methods |
These functions are generics, which means that packages can provide implementations (methods) for other classes. See the documentation of individual methods for extra arguments and differences in behaviour.
Methods available in currently loaded packages:
compute(): no methods found
collect(): no methods found
collapse(): no methods found
copy_to(), the opposite of collect(): it takes a local data
frame and uploads it to the remote source.
if (require(dbplyr)) {
mtcars2 <- src_memdb() %>%
copy_to(mtcars, name = "mtcars2-cc", overwrite = TRUE)
remote <- mtcars2 %>%
filter(cyl == 8) %>%
select(mpg:drat)
# Compute query and save in remote table
compute(remote)
# Compute query bring back to this session
collect(remote)
# Creates a fresh query based on the generated SQL
collapse(remote)
}Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.