Inspect the file plan for a scan

Reports which data files a scan would read, without reading them. This is how pushdown is verified rather than assumed: a filtered scan should plan fewer files, and fewer records, than an unfiltered one.

Usage

icebergr_scan_plan(scan)

Arguments

scan

An icebergr_scan from icebergr_scan().

Value

A tibble with one row per planned file task: data_file_path, record_count, file_size_in_bytes, start and length.

record_count is NA for a task covering part of a file, since a partial read has no meaningful record count from the manifest.

Examples

tbl <- icebergr_example_table(rows = 10)

# The example table has two data files, one per append.
all_files <- icebergr_scan_plan(icebergr_scan(tbl))
hot_files <- icebergr_scan_plan(icebergr_scan(tbl, filter = id > 1000))

nrow(hot_files) < nrow(all_files)
#> [1] TRUE
sum(hot_files$record_count) < sum(all_files$record_count)
#> [1] TRUE