Numeric Operation Functions

log2()

Supported, with differences.

• The display of decimal places is different from that in MySQL. Due to the limitation of the GaussDB floating-point data type, the extra_float_digits parameter is used to control the number of decimal places to be displayed.
• Due to the internal processing difference of the input precision, the calculation results of GaussDB and MySQL are different.
• The following data types are supported:
  • Integer types: bigint, int16, int, smallint, and tinyint.
  • Unsigned integer types: bigint unsigned, integer unsigned, smallint unsigned, and tinyint unsigned.
  • Floating-point number type: numeric and real.
  • Character string type: character, character varying, clob, and text. Only numeric integer strings are supported.
  • SET type.
  • NULL type.

log10()

Supported, with differences.

• The display of decimal places is different from that in MySQL. Due to the limitation of the GaussDB floating-point data type, the extra_float_digits parameter is used to control the number of decimal places to be displayed.
• Due to the internal processing difference of the input precision, the calculation results of GaussDB and MySQL are different.
• The following data types are supported:
  • Integer types: bigint, int16, int, smallint, and tinyint.
  • Unsigned integer types: bigint unsigned, integer unsigned, smallint unsigned, and tinyint unsigned.
  • Floating-point number type: numeric and real.
  • Character string type: character, character varying, clob, and text. Only numeric integer strings are supported.
  • SET type.
  • NULL type.

RAND([seed])

Supported, with differences.

Due to the random number generation algorithm used in the function, the random number returned by the function is different from that returned by MySQL.