PDF (US Ltr)
- 35.1Mb
PDF (A4)
- 35.2Mb
Man Pages (TGZ)
- 256.4Kb
Man Pages (Zip)
- 361.3Kb
Info (Gzip)
- 3.4Mb
Info (Zip)
- 3.4Mb
Search Results
https://dev.mysql.com/doc/refman/5.7/en/insert-optimization.html
Ideally, you make a single connection, send the data for many new rows at once, and delay all index updates and consistency checking until the very end. See Section 8.5.5, “Bulk Data Loading for InnoDB Tables” for tips specific to InnoDB tables.
https://dev.mysql.com/doc/refman/5.7/en/is-null-optimization.html
MySQL can perform the same optimization on col_name IS NULL that it can use for col_name = constant_value. 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 ...
https://dev.mysql.com/doc/refman/5.7/en/replication-features-temptables.html
The discussion in the following paragraphs does not apply when binlog_format=ROW because, in that case, temporary tables are not replicated; this means that there are never any temporary tables on the replica to be lost in the event of an unplanned ...If you stop the replica server, the temporary tables needed by those updates are no longer available when the replica is ...
https://dev.mysql.com/doc/refman/5.7/en/subquery-materialization.html
For subquery materialization to be used in MySQL, the optimizer_switch system variable materialization flag must be enabled. (oe_1, oe_2, ..., oe_N) [NOT] IN (SELECT ie_1, i_2, ..., ie_N ...) The predicate has this form, when there is a single outer ... The optimizer uses materialization to enable more efficient subquery ...
https://dev.mysql.com/doc/refman/5.7/en/sys-innodb-buffer-stats-by-schema.html
These views summarize the information in the INFORMATION_SCHEMA INNODB_BUFFER_PAGE table, grouped by schema. Warning Querying views that access the INNODB_BUFFER_PAGE table can affect performance. Do not query these views on a production system ...
https://dev.mysql.com/doc/refman/5.7/en/sys-innodb-buffer-stats-by-table.html
These views summarize the information in the INFORMATION_SCHEMA INNODB_BUFFER_PAGE table, grouped by schema and table. Warning Querying views that access the INNODB_BUFFER_PAGE table can affect performance. Do not query these views on a production ...
https://dev.mysql.com/doc/refman/5.7/en/sys-io-global-by-wait-by-latency.html
These views summarize global I/O consumers to display amount of I/O and time waiting for I/O, grouped by event. avg_read The average number of bytes per read for the I/O event. avg_written The average number of bytes per write for the I/O event.
https://dev.mysql.com/doc/refman/5.7/en/sys-memory-by-host-by-current-bytes.html
Rows for which the HOST column in the underlying Performance Schema table is NULL are assumed to be for background threads and are reported with a host name of background. current_count_used The current number of allocated memory blocks that have ...
https://dev.mysql.com/doc/refman/5.7/en/where-optimization.html
This section discusses optimizations that can be made for processing WHERE clauses. The examples use SELECT statements, but the same optimizations apply for WHERE clauses in DELETE and UPDATE statements. Note Because work on the MySQL optimizer is ...You might be tempted to rewrite your queries to make arithmetic operations faster, while sacrificing ...
https://dev.mysql.com/doc/refman/5.7/en/group-replication-single-primary-mode.html
In this mode the group has a single-primary server that is set to read-write mode. All the other members in the group are set to read-only mode (with super-read-only=ON ). The primary is typically the first server to bootstrap the group, all other ...Upon primary member failure, an automatic primary election mechanism chooses the new primary ...