Query Attribute Components •URN:  file://component_log_sink_json •Multiple uses permitted: Yes. •Output destination: This sink determines its output destination based on the default error log destination, which is given by the  log_error  system variable: •If  log_error  names a file, the sink bases output file naming on that file name, plus a numbered  . NN .json  suffix, with  NN  starting at 00. For example, if  log_error  is  file_name , successive instances of  log_sink_json  named in the  log_error_services  value write to file_name .00.json ,  file_name .01.json , and so forth. •If  log_error  is  stderr , the sink writes to the console. If  log_sink_json  is named multiple times in the  log_error_services  value, they all write to the console, which is likely not useful. •Performance Schema support: Writes to the  error_log  table. Provides a parser for reading error log files created by previous server instances. The log_sink_syseventlog Component •Purpose: Implements error logging to the system log. This is the Event Log on Windows, and  syslog  on Unix and Unix-like systems. See Section 5.4.2.8, “Error Logging to the System Log” . •URN:  file://component_log_sink_syseventlog •Multiple uses permitted: No. •Output destination: Writes to the system log. Does not use the default error log destination. •Performance Schema support: Does not write to the  error_log  table. Does not provide a parser for reading error log files created by previous server instances. The log_sink_test Component •Purpose: Intended for internal use in writing test cases, not for production use. •URN:  file://component_log_sink_test Sink properties such as whether multiple uses are permitted and the output destination are not specified for log_sink_test  because, as mentioned, it is for internal use. As such, its behavior is subject to change at any time. As of MySQL 8.0.23, a a component service provides access to query attributes (see Section 9.6, “Query Attributes” ). The  query_attributes  component uses this service to provide access to query attributes within SQL statements. 5.5.4 Query Attribute Components 5.6 MySQL Server Plugins 1072 Developers who wish to incorporate the same query-attribute component service used by query_attributes  should consult the  mysql_query_attributes.h  file in a MySQL source distribution. •URN:  file://component_query_attributes •Purpose: Implements the  mysql_query_attribute_string()  function that takes an attribute name argument and returns the attribute value as a string, or  NULL  if the attribute does not exist.