merge_sorted

merge_sorted combines two or more tables into one sorted, aggregate table. This essentially stacks the tables one on top of the other and sorts the result. Null tables are ignored. merge_sorted is more efficient than using merge followed by sort.

Syntax

merge_sorted(tables: list[Table], order_by: str) -> Table

Parameters

ParameterTypeDescription
tableslist[Table]

Source tables to be merged.

  • The tables to be merged must include the same columns of the same type.
  • Each table must be already sorted.
  • Null inputs are skipped.
order_bystr

The column by which to sort the merged table.

Returns

A new table with the source tables stacked one on top of the other and sorted by the specified column.

Examples

In the following example, source1 is stacked on top of source2, and the result is sorted based on the Number column.

from deephaven import merge_sorted, new_table
from deephaven.column import int_col, string_col

source1 = new_table(
    [string_col("Letter", ["A", "D", "E"]), int_col("Number", [3, 4, 7])]
)
source2 = new_table(
    [string_col("Letter", ["B", "C", "D"]), int_col("Number", [1, 2, 5])]
)

result = merge_sorted([source1, source2], "Letter")

In the following example, three tables are merged and sorted based on the Number column.

from deephaven import merge_sorted, new_table
from deephaven.column import int_col, string_col

source1 = new_table(
    [string_col("Letter", ["A", "C", "G"]), int_col("Number", [1, 6, 9])]
)
source2 = new_table(
    [string_col("Letter", ["B", "D", "G"]), int_col("Number", [3, 5, 8])]
)
source3 = new_table(
    [string_col("Letter", ["D", "E", "F"]), int_col("Number", [2, 4, 7])]
)

result = merge_sorted([source1, source2, source3], "Number")