Changes in MySQL 8.0 NO_AUTO_CREATE_USER  SQL mode, the  PASSWORD()  function, and the  old_passwords  system variable. Replication from MySQL 5.7 to 8.0 of statements that refer to these removed features can cause replication failure. Applications that use any of the removed features should be revised to avoid them and use alternatives when possible, as described in Features Removed in MySQL 8.0. To avoid a startup failure on MySQL 8.0, remove any instance of  NO_AUTO_CREATE_USER  from sql_mode  system variable settings in MySQL option files. Loading a dump file that includes the  NO_AUTO_CREATE_USER  SQL mode in stored program definitions into a MySQL 8.0 server causes a failure. As of MySQL 5.7.24 and MySQL 8.0.13,  mysqldump  removes NO_AUTO_CREATE_USER  from stored program definitions. Dump files created with an earlier version of mysqldump  must be modified manually to remove instances of  NO_AUTO_CREATE_USER . Removal of  MAXDB  means that the  TIMESTAMP  data type for  CREATE TABLE  or  ALTER TABLE  is no longer treated as  DATETIME . Replication from MySQL 5.7 to 8.0 of statements that refer to the removed SQL modes can cause replication failure. This includes replication of  CREATE  statements for stored programs (stored procedures and functions, triggers, and events) that are executed while the current  sql_mode  value includes any of the removed modes. Applications that use any of the removed modes should be revised to avoid them. A spatial column with an explicit  SRID  attribute is SRID-restricted: The column takes only values with that ID, and  SPATIAL  indexes on the column become subject to use by the optimizer. The optimizer ignores  SPATIAL  indexes on spatial columns with no  SRID  attribute. See Section 8.3.3, “SPATIAL Index Optimization” . If you want the optimizer to consider  SPATIAL  indexes on spatial columns that are not SRID-restricted, each such column should be modified: SELECT DISTINCT ST_SRID( col_name ) FROM  tbl_name ; If the query returns more than one row, the column contains a mix of SRIDs. In that case, modify its contents so all values have the same SRID. 273 •Several spatial functions were removed in MySQL 8.0.0 due to a spatial function namespace change that implemented an  ST_  prefix for functions that perform an exact operation, or an  MBR  prefix for functions that perform an operation based on minimum bounding rectangles. The use of removed spatial functions in generated column definitions could cause an upgrade failure. Before upgrading, run mysqlcheck --check-upgrade  for removed spatial functions and replace any that you find with their ST_  or  MBR  named replacements. For a list of removed spatial functions, refer to Features Removed in MySQL 8.0. •Recreate the  SPATIAL  index. •Redefine the column to have an explicit  SRID  attribute. •Verify that all values within the column have the same SRID. To determine the SRIDs contained in a geometry column  col_name , use the following query: •As of MySQL 8.0.3, spatial data types permit an  SRID  attribute, to explicitly indicate the spatial reference system (SRS) for values stored in the column. See Section 11.4.1, “Spatial Data Types” . •In MySQL 8.0.11, these deprecated compatibility SQL modes were removed:  DB2 ,  MAXDB , MSSQL ,  MYSQL323 ,  MYSQL40 ,  ORACLE ,  POSTGRESQL ,  NO_FIELD_OPTIONS ,  NO_KEY_OPTIONS , NO_TABLE_OPTIONS . They can no longer be assigned to the  sql_mode  system variable or used as permitted values for the  mysqldump --compatible  option.