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CLUSTERING_INFORMATION

Returns clustering information of a table.

Syntax

CLUSTERING_INFORMATION('<database_name>', '<table_name>')

Examples

CREATE TABLE mytable(a int, b int) CLUSTER BY(a+1);

INSERT INTO mytable VALUES(1,1),(3,3);
INSERT INTO mytable VALUES(2,2),(5,5);
INSERT INTO mytable VALUES(4,4);

SELECT * FROM CLUSTERING_INFORMATION('default','mytable')\G
*************************** 1. row ***************************
cluster_key: ((a + 1))
total_block_count: 3
constant_block_count: 1
unclustered_block_count: 0
average_overlaps: 1.3333
average_depth: 2.0
block_depth_histogram: {"00002":3}
ParameterDescription
cluster_keyThe defined cluster key.
total_block_countThe current count of blocks.
constant_block_countThe count of blocks where min/max values are equal, meaning each block contains only one (group of) cluster_key value.
unclustered_block_countThe count of blocks that have not yet been clustered.
average_overlapsThe average ratio of overlapping blocks within a given range.
average_depthThe average depth of overlapping partitions for the cluster key.
block_depth_histogramThe number of partitions at each depth level. A higher concentration of partitions at lower depths indicates more effective table clustering.
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