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https://dev.mysql.com/doc/refman/8.4/en/performance-schema-events-statements-history-long-table.html
When the table becomes full, the oldest row is discarded when a new row is added, regardless of which thread generated either row. The events_statements_history_long table contains the N most recent statement events that have ended globally, across ...
https://dev.mysql.com/doc/refman/8.4/en/performance-schema-events-transactions-history-long-table.html
When the table becomes full, the oldest row is discarded when a new row is added, regardless of which thread generated either row. The events_transactions_history_long table contains the N most recent transaction events that have ended globally, ...
https://dev.mysql.com/doc/refman/8.4/en/performance-schema-events-waits-history-long-table.html
When the table becomes full, the oldest row is discarded when a new row is added, regardless of which thread generated either row. The events_waits_history_long table contains N the most recent wait events that have ended globally, across all ...
https://dev.mysql.com/doc/refman/8.4/en/performance-schema-log-status-table.html
The log_status table has these columns: SERVER_UUID The server UUID for this server instance. This is the generated unique value of the read-only system variable server_uuid. The log_status table provides information that enables an online backup ...
https://dev.mysql.com/doc/refman/8.4/en/select-optimization.html
Tuning these statements is a top priority, whether to achieve sub-second response times for dynamic web pages, or to chop hours off the time to generate huge overnight reports. Set up indexes on columns used in the WHERE clause, to speed up ...
https://dev.mysql.com/doc/refman/8.4/en/sha256-pluggable-authentication.html
The server uses the sha256_password_auto_generate_rsa_keys system variable to determine whether to automatically generate the RSA key-pair files. MySQL provides two authentication plugins that implement SHA-256 hashing for user account passwords: ...
https://dev.mysql.com/doc/refman/8.4/en/signal.html
Item Name Definition --------- ---------- CLASS_ORIGIN VARCHAR(64) SUBCLASS_ORIGIN VARCHAR(64) CONSTRAINT_CATALOG VARCHAR(64) CONSTRAINT_SCHEMA VARCHAR(64) CONSTRAINT_NAME VARCHAR(64) CATALOG_NAME VARCHAR(64) SCHEMA_NAME VARCHAR(64) TABLE_NAME ...
https://dev.mysql.com/doc/refman/8.4/en/storage-engine-setting.html
By default, a warning is generated whenever CREATE TABLE or ALTER TABLE cannot use the default storage engine. Table and column definitions are stored in the MySQL data dictionary. When you create a new table, you can specify which storage engine ...
https://dev.mysql.com/doc/refman/8.4/en/string-functions-charset.html
An exception to the preceding principle occurs for expressions for virtual generated columns. MySQL has many operators and functions that return a string. This section answers the question: What is the character set and collation of such a string? ...
https://dev.mysql.com/doc/refman/8.4/en/table-size-limit.html
ALTER TABLE tbl_name MAX_ROWS=1000000000 AVG_ROW_LENGTH=nnn; You have to specify AVG_ROW_LENGTH only for tables with BLOB or TEXT columns; in this case, MySQL cannot optimize the space required based only on the number of rows. The effective ...