HLL Operators

Updated on 2024-12-19 GMT+08:00

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The HLL type supports the following operators:

Table 1 HLL Operators

HLL Operators

Description

Return Type

Example

Checks whether the values of hll and hll_hashval are equal.

bool

        
           SELECT (hll_empty() || hll_hash_integer(1)) = (hll_empty() || hll_hash_integer(1));
 ?column?
----------
 t
(1 row)

hll_hashval

        
           SELECT hll_hash_integer(1) = hll_hash_integer(1);
 ?column? 
----------
 t
(1 row)

<> or !=

Checks whetherthe values of hll and hll_hashval are not equal.

bool

        
           SELECT (hll_empty() || hll_hash_integer(1)) <> (hll_empty() || hll_hash_integer(2));
 ?column? 
----------
 t
(1 row)

hll_hashval

        
           SELECT hll_hash_integer(1) <> hll_hash_integer(2);
 ?column? 
----------
 t
(1 row)

Represents the functions of hll_add, hll_union, and hll_add_rev.

hll

hll_add

        
           SELECT hll_empty() || hll_hash_integer(1);
         ?column?         
--------------------------
 \x128b7f8895a3f5af28cafe
(1 row)

hll_add_rev

        
           SELECT hll_hash_integer(1) || hll_empty();
         ?column?         
--------------------------
 \x128b7f8895a3f5af28cafe
(1 row)

hll_union

        
           SELECT (hll_empty() || hll_hash_integer(1)) || (hll_empty() || hll_hash_integer(2));
                 ?column?                 
------------------------------------------
 \x128b7f8895a3f5af28cafeda0ce907e4355b60
(1 row)

Calculates the distinct value of the hll, which is equivalent to the hll_cardinality function.

integer

        
           SELECT #(hll_empty() || hll_hash_integer(1));
 ?column? 
----------
        1
(1 row)

Parent topic: HLL Functions and Operators

Previous topic: HLL Functions and Operators

Next topic: Hash Functions

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