Server System Variables Defines a limit for the number of schema definition objects, both used and unused, that can be kept in the dictionary object cache. Unused schema definition objects are only kept in the dictionary object cache when the number in use is less than the capacity defined by  schema_definition_cache . A setting of  0  means that schema definition objects are only kept in the dictionary object cache while they are in use. For more information, see Section 14.4, “Dictionary Object Cache” . • secure_file_priv Command-Line Format --secure-file-priv=dir_name System Variable secure_file_priv Scope Global Dynamic No SET_VAR  Hint Applies No Type String Default Value platform specific Valid Values empty string dirname NULL This variable is used to limit the effect of data import and export operations, such as those performed by the  LOAD DATA  and  SELECT ... INTO OUTFILE  statements and the  LOAD_FILE()  function. These operations are permitted only to users who have the  FILE  privilege. secure_file_priv  may be set as follows: •If empty, the variable has no effect. This is not a secure setting. •If set to the name of a directory, the server limits import and export operations to work only with files in that directory. The directory must exist; the server does not create it. •If set to  NULL , the server disables import and export operations. The default value is platform specific and depends on the value of the  INSTALL_LAYOUT CMake  option, as shown in the following table. To specify the default  secure_file_priv  value explicitly if you are building from source, use the  INSTALL_SECURE_FILE_PRIVDIR CMake  option. INSTALL_LAYOUT  Value Default  secure_file_priv  Value STANDALONE empty DEB ,  RPM ,  SVR4 /var/lib/mysql-files 871 Maximum Value 524288