Bit String Functions and Operators

Compared with the original openGauss, Dolphin modifies the bit string functions as follows:

  1. The bit_bool function is added.
  2. The ^ operator is added.
  3. The bit_count function is added.
  • bit_bool(bit)

    Description: Returns a Boolean value based on the data in the bit string. If the value is 0, false is returned. Otherwise, true is returned.

    Return type: Boolean

    Example:

    openGauss=# select bit_bool('11111');
     bit_bool 
    ----------
     t
    (1 row)
    
    openGauss=# select bit_bool('00001');
     bit_bool 
    ----------
     t
    (1 row)
    
    openGauss=# select bit_bool('00000');
     bit_bool 
    ----------
     f
    (1 row)
    
  • ^

    Description: Implements the bitwise XOR of bit-type data.

    Return type: bit

    Example:

    openGauss=# select b'1001'^b'1100';
     ?column? 
    ----------
     0101
    (1 row)
    
  • bit_count(N)

    Description: Returns the number of 1s in the binary string when the input data is converted to an unsigned 64-bit integer.

    Input type: numeric text bit

    Return type: text

    Note: If the entered number or character string exceeds the range of unsigned 64-bit integers, 64 is returned. If the number of 1s in the input bits exceeds 64, 1 is returned.

    Example:

    SELECT bit_count(29);
     bit_count 
    ----------
     4
    (1 row)
    
    SELECT bit_count(b'101010');
     bit_count 
    ----------
     3
    (1 row)
    
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    openGauss 2024-10-08 01:19:39
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