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/faqs-replication.html
On the source, issue the following statement to enable the source to begin processing updates again: mysql> UNLOCK TABLES; A.14.5. Thus, when the update of client A makes it to co-source 2, it produces tables that are different from what you have on ... In the following section, we provide answers to questions that are most frequently asked about MySQL ...
https://dev.mysql.com/doc/refman/8.0/en/group-replication-limitations.html
Group Replication cannot be started following a MySQL Server upgrade that uses the MINIMAL option (--upgrade=MINIMAL), which does not upgrade system tables on which the replication internals depend. Note For a group in multi-primary mode, unless you ... Limit on Group Size Limits on Transaction Size The following known limitations exist for Group ...
https://dev.mysql.com/doc/refman/8.0/en/index-merge-optimization.html
This access method merges index scans from a single table only, not scans across multiple tables. AND key_partN = constN Any range condition over the primary key of an InnoDB table. If all columns used in the query are covered by the used indexes, ... The Index Merge access method retrieves rows with multiple range scans and merges their results into ...
https://dev.mysql.com/doc/refman/8.0/en/innodb-memcached-dml.html
These operations are guaranteed to only affect one row when issued through the memcached interface, because the key is unique within the table. In the following SQL examples, t1 refers to the table used for memcached operations, based on the ...
https://dev.mysql.com/doc/refman/8.0/en/innodb-next-key-locking.html
Let the table contain rows having id values of 90 and 102. If the locks set on the index records in the scanned range do not lock out inserts made in the gaps (in this case, the gap between 90 and 102), another session can insert a new row into the ... The so-called phantom problem occurs within a transaction when the same query produces different sets of rows at different ...
https://dev.mysql.com/doc/refman/8.0/en/monitor-mysql-memory-use.html
Instruments can be enabled by updating the ENABLED column of the Performance Schema setup_instruments table. To view available MySQL memory instruments, query the Performance Schema setup_instruments table. After restarting the server, the ENABLED ... The following example demonstrates how to use Performance Schema and sys schema to monitor MySQL memory ...
https://dev.mysql.com/doc/refman/8.0/en/mysql-cluster-importing-data.html
You may also wish to do this when performing bulk DELETE or UPDATE operations on NDB Cluster tables. If a data import operation does not complete successfully, for whatever reason, you should be prepared to perform any necessary cleanup including ...
https://dev.mysql.com/doc/refman/8.0/en/optimize-character.html
The GROUP BY and ORDER BY clauses can generate temporary tables, and these temporary tables can use the MEMORY storage engine if the original table does not contain any BLOB columns. If a table contains string columns such as name and address, but ... For character and string columns, follow these guidelines: Use binary collation order for fast comparison and sort operations, when you do not need language-specific collation ...
https://dev.mysql.com/doc/refman/8.0/en/performance-schema-timing.html
For example, the standard gettimeofday() function can take hundreds of cycles, which is an unacceptable overhead for data gathering that may occur thousands or millions of times per second. Performance Schema Timer Representation in Events Rows in ... Events are collected by means of instrumentation added to the server source ...
https://dev.mysql.com/doc/refman/8.0/en/replication-features-reserved-words.html
For example, a table column named rank on a MySQL 5.7 source that is replicating to a MySQL 8.0 replica could cause a problem because RANK is a reserved word beginning in MySQL 8.0. Replication can fail in such cases with Error 1064 You have an ...