PDF (US Ltr)
- 43.2Mb
PDF (A4)
- 43.3Mb
Man Pages (TGZ)
- 295.2Kb
Man Pages (Zip)
- 400.4Kb
Info (Gzip)
- 4.3Mb
Info (Zip)
- 4.3Mb
Search Results
https://dev.mysql.com/doc/refman/8.0/en/innodb-adaptive-hash.html
Based on the observed pattern of searches, a hash index is built using a prefix of the index key. The adaptive hash index enables InnoDB to perform more like an in-memory database on systems with appropriate combinations of workload and sufficient ...
https://dev.mysql.com/doc/refman/8.0/en/innodb-change-buffer.html
During this time, disk I/O is increased, which can cause a significant slowdown for disk-bound queries. The change buffer is a special data structure that caches changes to secondary index pages when those pages are not in the buffer pool. The ...
https://dev.mysql.com/doc/refman/8.0/en/innodb-index-types.html
InnoDB uses this primary key value to search for the row in the clustered index. How the Clustered Index Speeds Up Queries Accessing a row through the clustered index is fast because the index search leads directly to the page that contains the row ... Each InnoDB table has a special index called the clustered index that stores row ...
https://dev.mysql.com/doc/refman/8.0/en/innodb-locking-reads.html
FOR UPDATE For index records the search encounters, locks the rows and any associated index entries, the same as if you issued an UPDATE statement for those rows. Your application code can ensure referential integrity throughout this sequence of ...
https://dev.mysql.com/doc/refman/8.0/en/innodb-standard-monitor.html
This limit does not apply to output written to server standard error output (stderr). Status This section shows the timestamp, the monitor name, and the number of seconds that per-second averages are based on. SEMAPHORES This section reports threads ... The Lock Monitor is the same as the Standard Monitor except that it includes additional lock ...
https://dev.mysql.com/doc/refman/8.0/en/is-null-optimization.html
For example, MySQL can use indexes and ranges to search for NULL with IS NULL. This optimization does not occur in cases when the column might produce NULL anyway (for example, if it comes from a table on the right side of a LEFT JOIN). This ...
https://dev.mysql.com/doc/refman/8.0/en/monitor-innodb-mutex-waits-performance-schema.html
For example, to disable InnoDB mutex wait event instruments related to full-text search, add the following rule: performance-schema-instrument='wait/synch/mutex/innodb/fts%=OFF' Note Rules with a longer prefix such as wait/synch/mutex/innodb/fts% ...
https://dev.mysql.com/doc/refman/8.0/en/myisamchk-other-options.html
This improves join performance by enabling the join optimizer to better choose the order in which to join the tables and which indexes it should use. --block-search=offset, -b offset Command-Line Format --block-search=offset Type Numeric Find the ...
https://dev.mysql.com/doc/refman/8.0/en/optimize-table.html
To keep the index maintenance period to a reasonable time, set the innodb_ft_num_word_optimize option to specify how many words to update in the search index, and run a sequence of OPTIMIZE TABLE statements until the search index is fully updated.
https://dev.mysql.com/doc/refman/8.0/en/optimizer-features-to-trace.html
They are: Greedy search: With an N-table join, this could explore factorial(N) plans. These switches are listed here: greedy_search: Greedy search is not traced. dynamic_range: Only the first call to the range optimizer on this JOIN_TAB::SQL_SELECT ... Some features in the optimizer can be invoked many times during statement optimization and execution, and thus can make the trace grow beyond ...