Shows what would happen if you ran db_hive_write() without
actually writing any data. Useful for validating writes before execution.
Usage
db_preview_hive_write(
data,
section,
dataset,
partition_by = NULL,
mode = c("overwrite", "append", "ignore", "replace_partitions")
)Arguments
- data
A data.frame / tibble
- section
Your section name
- dataset
The name of the dataset
- partition_by
Character vector of column names to partition by (e.g. c("year","month"))
- mode
One of:
"overwrite": replace target files
"append": add new files (requires unique filenames)
"ignore": write only if target path does not exist (best-effort; still race-prone)
"replace_partitions": delete only affected partition folders, then append fresh files (requires partition_by)
Examples
if (FALSE) { # \dontrun{
db_connect()
# Preview before writing
db_preview_hive_write(my_data, "Trade", "Imports", partition_by = "year")
# If preview looks good, actually write
db_hive_write(my_data, "Trade", "Imports", partition_by = "year")
} # }