hll_from_base64

description

Syntax

HLL HLL_FROM_BASE64(VARCHAR input)

Convert a base64 string(result of function hll_to_base64) into a hll. If input string is invalid, return NULL.

example

  1. mysql> select hll_union_agg(hll_from_base64(hll_to_base64(pv))), hll_union_agg(pv) from test_hll;
  2. +---------------------------------------------------+-------------------+
  3. | hll_union_agg(hll_from_base64(hll_to_base64(pv))) | hll_union_agg(pv) |
  4. +---------------------------------------------------+-------------------+
  5. |                                                 3 |                 3 |
  6. +---------------------------------------------------+-------------------+
  7. 1 row in set (0.04 sec)
  9. mysql>  select hll_cardinality(hll_from_base64(hll_to_base64(hll_hash('abc'))));
  10. +------------------------------------------------------------------+
  11. | hll_cardinality(hll_from_base64(hll_to_base64(hll_hash('abc')))) |
  12. +------------------------------------------------------------------+
  13. |                                                                1 |
  14. +------------------------------------------------------------------+
  15. 1 row in set (0.04 sec)
  17. mysql> select hll_cardinality(hll_from_base64(hll_to_base64(hll_hash(''))));
  18. +---------------------------------------------------------------+
  19. | hll_cardinality(hll_from_base64(hll_to_base64(hll_hash('')))) |
  20. +---------------------------------------------------------------+
  21. |                                                             1 |
  22. +---------------------------------------------------------------+
  23. 1 row in set (0.02 sec)
  25. mysql> select hll_cardinality(hll_from_base64(hll_to_base64(hll_hash(NULL))));
  26. +-----------------------------------------------------------------+
  27. | hll_cardinality(hll_from_base64(hll_to_base64(hll_hash(NULL)))) |
  28. +-----------------------------------------------------------------+
  29. |                                                               0 |
  30. +-----------------------------------------------------------------+
  31. 1 row in set (0.02 sec)

keywords

HLL_FROM_BASE64, HLL