HLL_FROM_BASE64
Description
Converts a base64-encoded string (usually the result of the HLL_TO_BASE64 function) into an HLL. If the input string is invalid or NULL, the function returns NULL.
Syntax
HLL_FROM_BASE64(<input>)Parameters
| Parameter | Description |
|---|---|
<input> | A base64-encoded string, typically generated by the HLL_TO_BASE64 function. If the input string is invalid or NULL, the function returns NULL. |
Examples
select hll_union_agg(hll_from_base64(hll_to_base64(pv))), hll_union_agg(pv) from test_hll;+---------------------------------------------------+-------------------+
| hll_union_agg(hll_from_base64(hll_to_base64(pv))) | hll_union_agg(pv) |
+---------------------------------------------------+-------------------+
| 3 | 3 |
+---------------------------------------------------+-------------------+select hll_cardinality(hll_from_base64(hll_to_base64(hll_hash('abc'))));+------------------------------------------------------------------+
| hll_cardinality(hll_from_base64(hll_to_base64(hll_hash('abc')))) |
+------------------------------------------------------------------+
| 1 |
+------------------------------------------------------------------+select hll_cardinality(hll_from_base64(hll_to_base64(hll_hash(''))));+---------------------------------------------------------------+
| hll_cardinality(hll_from_base64(hll_to_base64(hll_hash('')))) |
+---------------------------------------------------------------+
| 1 |
+---------------------------------------------------------------+select hll_cardinality(hll_from_base64(hll_to_base64(hll_hash(NULL))));+-----------------------------------------------------------------+
| hll_cardinality(hll_from_base64(hll_to_base64(hll_hash(NULL)))) |
+-----------------------------------------------------------------+
| 0 |
+-----------------------------------------------------------------+