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HPL/SQL is included to Apache Hive since version 2.0

part-count-by

PART_COUNT_BY Function

PART_COUNT_BY function returns the number partitions grouped by specified partition columns in the table.

Syntax:

PART_COUNT_BY([db_name.]table_name, [part_col, ...]); 

Parameters:

[dbname.]table_name Identifier, variable or expression
part_col One or more partition columns used for aggregation

Return Value:

  • The number of top-level partitions if part_col is not specified
  • Partition value and total number of existing partitions with the same value if part_col is not specified

Examples:

Table db.orders is partitioned by dt and region columns and has the following partitions:

dt=2015-09-01/region=1
dt=2015-09-01/region=2
dt=2015-09-02/region=1
dt=2015-09-03/region=3
dt=2015-09-03/region=2

Get the total number of distinct top-level partitions (dt=2015-09-01, dt=2015-09-02 and dt=2015-09-03):

part_count_by(db.orders); 
--
3

Get the top level partitions and the number of its sub-partitions:

part_count_by(db.orders, dt); 
--
dt=2015-09-01   2
dt=2015-09-02   1
dt=2015-09-03   2

Get the number of specified partitions:

part_count_by(db.orders, region); 
--
region=1    2
region=2    2
region=3    1

Compatibility: HPL/SQL extension.

Version: HPL/SQL 0.3.13

See also: