Search Results
https://dev.mysql.com/doc/internals/en/myisammrg-directory.html
As with other table handlers, you'll find that the *.c files in the myissammrg directory have counterparts in the myisam directory. In fact, this general description of a myisammrg program is almost always true: The myisammrg function checks an ...
https://dev.mysql.com/doc/mysql-em-plugin/en/myoem-config-metric-connection-category.html
Connect Timeout The number of seconds that the MySQL server waits for a connect packet before responding with 'Bad handshake'. Interactive Timeout The number of seconds the server waits for activity on an interactive connection before closing it.
https://dev.mysql.com/doc/c-api/8.4/en/c-api-prepared-statement-interface.html
Then it is executed one or more times at a later time, using the statement handler returned by the initialization function. In the case of direct execution, the query is parsed every time it is executed. Prepared execution is an efficient way to ...
https://dev.mysql.com/doc/refman/8.4/en/controlling-query-plan-evaluation.html
The task of the query optimizer is to find an optimal plan for executing an SQL query. Because the difference in performance between “good” and “bad” plans can be orders of magnitude (that is, seconds versus hours or even days), most query ...For join queries, the number of possible plans investigated by the MySQL optimizer grows exponentially with the number of tables referenced in a ...
https://dev.mysql.com/doc/refman/8.4/en/myisam-storage-engine.html
Table 18.2 MyISAM Storage Engine Features Feature Support B-tree indexes Yes Backup/point-in-time recovery (Implemented in the server, rather than in the storage engine.) Yes Cluster database support No Clustered indexes No Compressed data Yes ...
https://dev.mysql.com/doc/connector-odbc/en/connector-odbc-usagenotes-apptips-microsoft-excel.html
If you have problems importing data into Microsoft Excel, particularly numeric, date, and time values, this is probably because of a bug in Excel, where the column type of the source data is used to determine the data type when that data is ...The ...
https://dev.mysql.com/doc/refman/8.4/en/programs-overview.html
mysql_tzinfo_to_sql This program loads the time zone tables in the mysql database using the contents of the host system zoneinfo database (the set of files describing time zones). MySQL client programs that connect to the MySQL server: mysql The ...
https://dev.mysql.com/doc/refman/8.4/en/performance-schema-functions.html
FORMAT_PICO_TIME(time_val) Given a numeric Performance Schema latency or wait time in picoseconds, converts it to human-readable format and returns a string consisting of a value and a units indicator. Times under 1 nanosecond are represented as ...
https://dev.mysql.com/doc/refman/8.4/en/timestamp-initialization.html
If a TIMESTAMP or DATETIME column definition includes an explicit fractional seconds precision value anywhere, the same value must be used throughout the column definition. TIMESTAMP and DATETIME columns can be automatically initialized and updated ...An auto-updated column remains unchanged if all other columns are set to their current ...
https://dev.mysql.com/doc/internals/en/optimizer-features-to-trace.html
Some features in the optimizer can be invoked many times during statement optimization and execution, and thus can make the trace grow beyond reason. They are: Greedy search: with a N-table join, this could explore factorial(N) plans Range ...