MySQL 5.7 Reference Manual Including MySQL NDB Cluster 7.5 and NDB Cluster 7.6
A.1.1. | Which version of MySQL is production-ready (GA)? |
MySQL 8.0, 5.7, and MySQL 5.6 are supported for production use. MySQL 8.0 achieved General Availability (GA) status with MySQL 8.0.11, which was released for production use on 19 April 2018. MySQL 5.7 achieved General Availability (GA) status with MySQL 5.7.9, which was released for production use on 21 October 2015. MySQL 5.6 achieved General Availability (GA) status with MySQL 5.6.10, which was released for production use on 5 February 2013. MySQL 5.5 achieved General Availability (GA) status with MySQL 5.5.8, which was released for production use on 3 December 2010. Active development for MySQL 5.5 has ended. MySQL 5.1 achieved General Availability (GA) status with MySQL 5.1.30, which was released for production use on 14 November 2008. Active development for MySQL 5.1 has ended. MySQL 5.0 achieved General Availability (GA) status with MySQL 5.0.15, which was released for production use on 19 October 2005. Active development for MySQL 5.0 has ended. | |
A.1.2. | Can MySQL 5.7 do subqueries? |
Yes. See Section 13.2.10, “Subqueries”. | |
A.1.3. | Can MySQL 5.7 perform multiple-table inserts, updates, and deletes? |
Yes. For the syntax required to perform multiple-table updates, see Section 13.2.11, “UPDATE Statement”; for that required to perform multiple-table deletes, see Section 13.2.2, “DELETE Statement”.
A multiple-table insert can be accomplished using a trigger
whose | |
A.1.4. | Does MySQL 5.7 have a Query Cache? Does it work on Server, Instance or Database? |
Yes. (However, the query cache is deprecated as of MySQL 5.7.20, and is removed in MySQL 8.0.) The query cache operates on the server level, caching complete result sets matched with the original query string. If an exactly identical query is made (which often happens, particularly in web applications), no parsing or execution is necessary; the result is sent directly from the cache. Various tuning options are available. See Section 8.10.3, “The MySQL Query Cache”. | |
A.1.5. | Does MySQL 5.7 have Sequences? |
No. However, MySQL has an | |
A.1.6. |
Does MySQL 5.7 have a
|
Yes, see Section 11.2.7, “Fractional Seconds in Time Values”. | |
A.1.7. | Does MySQL 5.7 work with multi-core processors? |
Yes. MySQL is fully multithreaded, and makes use of all CPUs made available to it. Not all CPUs may be available; modern operating systems should be able to utilize all underlying CPUs, but also make it possible to restrict a process to a specific CPU or sets of CPUs. On Windows, there is currently a limit to the number of (logical) processors that mysqld can use: a single processor group, which is limited to a maximum of 64 logical processors. Use of multiple cores may be seen in these ways:
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A.1.8. | Why do I see multiple processes for mysqld? |
mysqld is a single-process program, not a multi-process program, and does not fork or launch other processes. However, mysqld is multithreaded and some process-reporting system utilities display separate entries for each thread of multithreaded processes, which may lead to the appearance of multiple mysqld processes when in fact there is only one. | |
A.1.9. | Can MySQL 5.7 perform ACID transactions? |
Yes. All current MySQL versions support transactions. The
The |