Stream top-k rows by a numeric column

Finds the top k rows by col without collecting the full dataset.

Usage

stream_top_k(x, col, k = 10L, decreasing = TRUE, na_drop = TRUE)

Arguments

x

A shard_row_groups or shard_dataset handle.

col

Column name to rank by.

k

Number of rows to keep.

decreasing

Logical; TRUE for largest values (default TRUE).

na_drop

Logical; drop rows where col is NA (default TRUE).

Value

A data.frame (or tibble if the tibble package is installed) with at most k rows ordered by col.

Details

For native-encoded partitions, this selects candidate rows using the numeric column without decoding strings, then decodes only the chosen rows for the returned result.

Examples

# \donttest{
s <- schema(x = float64())
sink <- table_sink(s, mode = "row_groups")
table_write(sink, 1L, data.frame(x = c(3.0, 1.0, 2.0)))
rg <- table_finalize(sink)
stream_top_k(rg, "x", k = 2L)
#> # A tibble: 2 × 1
#>       x
#>   <dbl>
#> 1     3
#> 2     2
# }