Server-Side Help Support Priority Range Windows Priority Level 0 THREAD_PRIORITY_NORMAL 1 to 10 THREAD_PRIORITY_BELOW_NORMAL 11 to 19 THREAD_PRIORITY_LOWEST 5.1.17 Server-Side Help Support MySQL Server supports a  HELP  statement that returns information from the MySQL Reference Manual (see Section 13.8.3, “HELP Statement” ). This information is stored in several tables in the  mysql  schema (see Section 5.3, “The mysql System Schema” ). Proper operation of the  HELP  statement requires that these help tables be initialized. For a new installation of MySQL using a binary or source distribution on Unix, help-table content initialization occurs when you initialize the data directory (see Section 2.10.1, “Initializing the Data Directory” ). For an RPM distribution on Linux or binary distribution on Windows, content initialization occurs as part of the MySQL installation process. For a MySQL upgrade using a binary distribution, help-table content is upgraded automatically by the server as of MySQL 8.0.16. Prior to MySQL 8.0.16, the content is not upgraded automatically, but you can upgrade it manually. Locate the  fill_help_tables.sql  file in the  share  or  share/mysql  directory. Change location into that directory and process the file with the  mysql  client as follows: The command shown here assumes that you connect to the server using an account such as  root  that has privileges for modifying tables in the  mysql  schema. Adjust the connection parameters as required. Prior to MySQL 8.0.16, if you are working with Git and a MySQL development source tree, the source tree contains only a “stub”  version of  fill_help_tables.sql . To obtain a non-stub copy, use one from a source or binary distribution. Each MySQL series has its own series-specific reference manual, so help-table content is series specific as well. This has implications for replication because help- table content should match the MySQL series. If you load MySQL 8.0 help content into a MySQL 8.0 replication server, it does not make sense to replicate that content to a replica server from a different MySQL series and for which that content is not appropriate. For this reason, as you upgrade individual servers in a replication scenario, you should upgrade each server’s help tables, using the instructions given earlier. (Manual help-content upgrade is necessary only for replication servers from versions lower than 8.0.16. As mentioned in the preceding instructions, content upgrades occur automatically as of MySQL 8.0.16.) The MySQL server implements several session state trackers. A client can enable these trackers to receive notification of changes to its session state. One use for the tracker mechanism is to provide a means for MySQL connectors and client applications to determine whether any session context is available to permit session migration from one server to another. (To change sessions in a load-balanced environment, it is necessary to detect whether there is session state to take into consideration when deciding whether a switch can be made.) 1010 5.1.18 Server Tracking of Client Session State Changes Note mysql -u root -p mysql < fill_help_tables.sql