timescaledb_information.compression_settings

Get information about compression-related settings for hypertables. Each row of the view provides information about individual orderby and segmentby columns used by compression.

Available columns

NameTypeDescription
hypertable_schemaTEXTSchema name of the hypertable
hypertable_nameTEXTTable name of the hypertable
attnameTEXTName of the column used in the compression settings
segmentby_column_indexSMALLINTPosition of attname in the compress_segmentby list
orderby_column_indexSMALLINTPosition of attname in the compress_orderby list
orderby_ascBOOLEANTrue if this is used for order by ASC, False for order by DESC
orderby_nullsfirstBOOLEANTrue if nulls are ordered first for this column, False if nulls are ordered last

Sample usage

  2. CREATE TABLE hypertab (a_col integer, b_col integer, c_col integer, d_col integer, e_col integer);
  4. SELECT table_name FROM create_hypertable('hypertab', 'a_col', chunk_time_interval => 864000000);
  6. ALTER TABLE hypertab SET (timescaledb.compress, timescaledb.compress_segmentby = 'a_col,b_col', 
  9.   timescaledb.compress_orderby = 'c_col desc, d_col asc nulls last');
  11. SELECT * FROM timescaledb_information.compression_settings WHERE hypertable_name = 'hypertab';
  13. -[ RECORD 1 ]----------+---------
  15. hypertable_schema      | public
  17. hypertable_name        | hypertab
  19. attname                | a_col
  21. segmentby_column_index | 1
  23. orderby_column_index   | 
  26. orderby_asc            | 
  29. orderby_nullsfirst     | 
  32. -[ RECORD 2 ]----------+---------
  34. hypertable_schema      | public
  36. hypertable_name        | hypertab
  38. attname                | b_col
  40. segmentby_column_index | 2
  42. orderby_column_index   | 
  45. orderby_asc            | 
  48. orderby_nullsfirst     | 
  51. -[ RECORD 3 ]----------+---------
  53. hypertable_schema      | public
  55. hypertable_name        | hypertab
  57. attname                | c_col
  59. segmentby_column_index | 
  62. orderby_column_index   | 1
  64. orderby_asc            | f
  66. orderby_nullsfirst     | t
  68. -[ RECORD 4 ]----------+---------
  70. hypertable_schema      | public
  72. hypertable_name        | hypertab
  74. attname                | d_col
  76. segmentby_column_index | 
  79. orderby_column_index   | 2
  81. orderby_asc            | t
  83. orderby_nullsfirst     | f