Get metadata about the chunks of hypertables.
This view shows metadata for the chunk's primary time-based dimension. For information about a hypertable's secondary dimensions, the dimensions view should be used instead.
If the chunk's primary dimension is of a time datatype, range_start and
range_end are set. Otherwise, if the primary dimension type is integer based,
range_start_integer and range_end_integer are set.
| Name | Type | Description |
|---|---|---|
hypertable_schema | TEXT | Schema name of the hypertable |
hypertable_name | TEXT | Table name of the hypertable |
chunk_schema | TEXT | Schema name of the chunk |
chunk_name | TEXT | Name of the chunk |
primary_dimension | TEXT | Name of the column that is the primary dimension |
primary_dimension_type | REGTYPE | Type of the column that is the primary dimension |
range_start | TIMESTAMP WITH TIME ZONE | Start of the range for the chunk's dimension |
range_end | TIMESTAMP WITH TIME ZONE | End of the range for the chunk's dimension |
range_start_integer | BIGINT | Start of the range for the chunk's dimension, if the dimension type is integer based |
range_end_integer | BIGINT | End of the range for the chunk's dimension, if the dimension type is integer based |
is_compressed | BOOLEAN | Is the data in the chunk compressed? Note that for distributed hypertables, this is the cached compression status of the chunk on the access node. The cached status on the access node and data node is not in sync in some scenarios. For example, if a user compresses or decompresses the chunk on the data node instead of the access node, or sets up compression policies directly on data nodes. Use chunk_compression_stats() function to get real-time compression status for distributed chunks. |
chunk_tablespace | TEXT | Tablespace used by the chunk |
data_nodes | ARRAY | Nodes on which the chunk is replicated. This is applicable only to chunks for distributed hypertables |
chunk_creation_time | TIMESTAMP WITH TIME ZONE | The time when this chunk was created for data addition |
Get information about the chunks of a hypertable.
Note
Dimension builder by_range was introduced in TimescaleDB 2.13. The chunk_creation_time metadata was introduced in TimescaleDB 2.13.
CREATE TABLESPACE tablespace1 location '/usr/local/pgsql/data1';CREATE TABLE hyper_int (a_col integer, b_col integer, c integer);SELECT table_name from create_hypertable('hyper_int', by_range('a_col', 10));CREATE OR REPLACE FUNCTION integer_now_hyper_int() returns int LANGUAGE SQL STABLE as $$ SELECT coalesce(max(a_col), 0) FROM hyper_int $$;SELECT set_integer_now_func('hyper_int', 'integer_now_hyper_int');INSERT INTO hyper_int SELECT generate_series(1,5,1), 10, 50;SELECT attach_tablespace('tablespace1', 'hyper_int');INSERT INTO hyper_int VALUES( 25 , 14 , 20), ( 25, 15, 20), (25, 16, 20);SELECT * FROM timescaledb_information.chunks WHERE hypertable_name = 'hyper_int';-[ RECORD 1 ]----------+----------------------hypertable_schema | publichypertable_name | hyper_intchunk_schema | _timescaledb_internalchunk_name | _hyper_7_10_chunkprimary_dimension | a_colprimary_dimension_type | integerrange_start |range_end |range_start_integer | 0range_end_integer | 10is_compressed | fchunk_tablespace |data_nodes |-[ RECORD 2 ]----------+----------------------hypertable_schema | publichypertable_name | hyper_intchunk_schema | _timescaledb_internalchunk_name | _hyper_7_11_chunkprimary_dimension | a_colprimary_dimension_type | integerrange_start |range_end |range_start_integer | 20range_end_integer | 30is_compressed | fchunk_tablespace | tablespace1data_nodes |
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