The following is a list of all function differences between MariaDB 10.5 and MySQL 8.0. It is based on functions available in the MySQL 8.0.17 and the MariaDB 10.5.19 releases. For a more complete list of differences, see Incompatibilities and Feature Differences Between MariaDB 10.5 and MySQL 8.0
NVL (Synonym for IFNULL)
VALUE - the VALUES() function was renamed after MariaDB introduced Table Value Constructors.
MySQL has removed the following functions in MySQL 8.0.
MariaDB and MySQL have differing GTID implementations.
GTID_SUBSET
GTID_SUBTRACT
WAIT_FOR_EXECUTED_GTID_SET
WAIT_UNTIL_SQL_THREAD_AFTER_GTIDS()
GeomCollection
MBRCoveredBy
MBRCovers
ST_Buffer_Strategy
ST_GeoHash
ST_GeomCollFromTxt
ST_IsValid
ST_LatFromGeoHash
ST_Latitude
ST_LongFromGeoHash
ST_Longitude
ST_MakeEnvelope
ST_NumInteriorRing
ST_PointFromGeoHash
ST_Simplify
ST_SwapXY
ST_Transform
ST_Validate
JSON_OVERLAPS
JSON_SCHEMA_VALID (MDEV-27128)
JSON_SCHEMA_VALIDATION_REPORT
JSON_STORAGE_FREE
JSON_STORAGE_SIZE (MDEV-17397)
JSON_TABLE
MEMBER_OF operator
REGEXP_LIKE (MDEV-16599)
BIN_TO_UUID
IS_UUID
UUID_TO_BIN
ANY_VALUE
FORMAT_BYTES (MDEV-19629)
FORMAT_PICO_TIME (MDEV-19629)
GROUPING (MDEV-32789)
PS_THREAD_ID (MDEV-19629)
PS_CURRENT_THREAD_ID
RANDOM_BYTES
VALIDATE_PASSWORD_STRENGTH