List the sort keys of tables in a lake

Reads the current sort order from the DuckLake metadata catalog, the counterpart of get_table_partitions() for set_table_sorting().

Usage

get_table_sorting(table_name = NULL, ducklake_name = NULL)

Arguments

table_name

Optional table name to filter to a single table, optionally qualified as "schema.table".

ducklake_name

Optional name of the attached DuckLake catalog. If NULL, the current database is used.

Value

A data frame with one row per sort key: schema_name, table_name, sort_key_index, expression, sort_direction ("ASC" or "DESC"), and null_order ("NULLS_FIRST" or "NULLS_LAST"). Zero rows when nothing is sorted.

See also

set_table_sorting(), get_table_partitions()

Other sorting: reset_table_sorting(), set_table_sorting()

Examples

lake_dir <- tempfile("getsort_lake_")
dir.create(lake_dir)
attach_ducklake("getsort_lake", lake_path = lake_dir)
create_table(mtcars, "cars")

set_table_sorting("cars", c("cyl ASC", "mpg DESC"))
#> Table "cars" is now sorted by "cyl ASC" and "mpg DESC".
#> ℹ Only newly written data is sorted; existing files keep their layout until
#>   compaction.

# All sorted tables in the lake
get_table_sorting()
#>   schema_name table_name sort_key_index expression sort_direction null_order
#> 1        main       cars              0        cyl            ASC NULLS_LAST
#> 2        main       cars              1        mpg           DESC NULLS_LAST

# Keys for one table
get_table_sorting("cars")
#>   schema_name table_name sort_key_index expression sort_direction null_order
#> 1        main       cars              0        cyl            ASC NULLS_LAST
#> 2        main       cars              1        mpg           DESC NULLS_LAST

detach_ducklake("getsort_lake", shutdown = TRUE)
unlink(lake_dir, recursive = TRUE)