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https://dev.mysql.com/doc/refman/8.4/en/information-schema-innodb-buffer-page-lru-table.html
The INNODB_BUFFER_PAGE_LRU table has the same columns as the INNODB_BUFFER_PAGE table with a few exceptions. It has LRU_POSITION and COMPRESSED columns instead of BLOCK_ID and PAGE_STATE columns, and it does not include and IS_STALE column. The ...
https://dev.mysql.com/doc/refman/8.4/en/mysql-cluster-ndbinfo-transporters.html
This information is shown in the table's status column, which can have any one of the following values: CONNECTING, CONNECTED, DISCONNECTING, or DISCONNECTED. The remote_address is the host name or address for the node whose ID is shown in the ...
https://dev.mysql.com/doc/refman/8.4/en/optimizing-innodb-queries.html
Follow these guidelines for InnoDB indexes: Because each InnoDB table has a primary key (whether you request one or not), specify a set of primary key columns for each table, columns that are used in the most important and time-critical queries. Do ... To tune queries for InnoDB tables, create an appropriate set of indexes on each ...
https://dev.mysql.com/doc/refman/8.4/en/partitioning-pruning.html
When the optimizer can make use of partition pruning in performing this query, execution of the query can be an order of magnitude faster than the same query against a nonpartitioned table containing the same column definitions and data. The ... The ...
https://dev.mysql.com/doc/refman/8.4/en/performance-schema-error-summary-tables.html
Each error summary table has three columns that identify the error: ERROR_NUMBER is the numeric error value. row *************************** ERROR_NUMBER: 1317 ERROR_NAME: ER_QUERY_INTERRUPTED SQL_STATE: 70100 SUM_ERROR_RAISED: 1 SUM_ERROR_HANDLED: ... The Performance Schema maintains summary tables for aggregating statistical information about server errors (and ...
https://dev.mysql.com/doc/refman/8.4/en/performance-schema-file-summary-tables.html
Each file I/O summary table has one or more grouping columns to indicate how the table aggregates events. Event names refer to names of event instruments in the setup_instruments table: file_summary_by_event_name has an EVENT_NAME column. Each file ... The Performance Schema maintains file I/O summary tables that aggregate information about I/O ...
https://dev.mysql.com/doc/refman/8.4/en/performance-schema-replication-tables.html
The following sections describe each replication table in more detail, including the correspondence between the columns produced by SHOW REPLICA STATUS and the replication table columns in which the same information appears. At this time, there are ...This is similar to the information available from the SHOW REPLICA STATUS statement, but representation in table form is more accessible and has usability benefits: SHOW REPLICA STATUS output is useful for visual inspection, but not so much for programmatic ...
https://dev.mysql.com/doc/refman/8.4/en/problems-with-null.html
For example, the following statements are completely different: mysql> INSERT INTO my_table (phone) VALUES (NULL); mysql> INSERT INTO my_table (phone) VALUES (''); Both statements insert a value into the phone column, but the first inserts a NULL ...
https://dev.mysql.com/doc/refman/8.4/en/spatial-type-overview.html
The SRID attribute makes a spatial column SRID-restricted, which has these implications: The column can contain only values with the given SRID. Spatial columns with no SRID attribute are not SRID-restricted and accept values with any SRID. However, ... MySQL has spatial data types that correspond to OpenGIS ...
https://dev.mysql.com/doc/mysql-cluster-manager/8.4/en/mcm-show-status.html
The Status column contains a description of the cluster's status; possible values and their meanings are shown in the following table: Table 5.1 Status values shown by show status --cluster Status Value Meaning fully operational All cluster ... show ...