Server Status Variables • Caching_sha2_password_rsa_public_key • Com_ xxx The public key used by the  caching_sha2_password  authentication plugin for RSA key pair- based password exchange. The value is nonempty only if the server successfully initializes the private and public keys in the files named by the  caching_sha2_password_private_key_path and  caching_sha2_password_public_key_path  system variables. The value of Caching_sha2_password_rsa_public_key  comes from the latter file. The  Com_ xxx  statement counter variables indicate the number of times each  xxx  statement has been executed. There is one status variable for each type of statement. For example,  Com_delete and  Com_update  count  DELETE  and  UPDATE  statements, respectively.  Com_delete_multi  and Com_update_multi  are similar but apply to  DELETE  and  UPDATE  statements that use multiple-table syntax. All  Com_stmt_ xxx  variables are increased even if a prepared statement argument is unknown or an error occurred during execution. In other words, their values correspond to the number of requests issued, not to the number of requests successfully completed. For example, because status variables are initialized for each server startup and do not persist across restarts, the  Com_restart  and Com_shutdown  variables that track  RESTART  and  SHUTDOWN  statements normally have a value of zero, but can be nonzero if  RESTART  or  SHUTDOWN  statements were executed but failed. The  Com_stmt_ xxx  status variables are as follows: • Com_stmt_prepare • Com_stmt_execute • Com_stmt_fetch • Com_stmt_send_long_data • Com_stmt_reset • Com_stmt_close Those variables stand for prepared statement commands. Their names refer to the  COM_ xxx  command set used in the network layer. In other words, their values increase whenever prepared statement API calls such as  mysql_stmt_prepare() ,  mysql_stmt_execute() , and so forth are executed. However,  Com_stmt_prepare ,  Com_stmt_execute  and  Com_stmt_close  also increase for PREPARE ,  EXECUTE , or  DEALLOCATE PREPARE , respectively. Additionally, the values of the older statement counter variables  Com_prepare_sql ,  Com_execute_sql , and  Com_dealloc_sql increase for the  PREPARE ,  EXECUTE , and  DEALLOCATE PREPARE  statements.  Com_stmt_fetch stands for the total number of network round-trips issued when fetching from cursors. Com_stmt_reprepare  indicates the number of times statements were automatically reprepared by the server, for example, after metadata changes to tables or views referred to by the statement. A reprepare operation increments  Com_stmt_reprepare , and also  Com_stmt_prepare . Com_explain_other  indicates the number of  EXPLAIN FOR CONNECTION  statements executed. See Section 8.8.4, “Obtaining Execution Plan Information for a Named Connection” . Com_change_repl_filter  indicates the number of  CHANGE REPLICATION FILTER  statements executed. • Compression 949