Configuration Differences in MySQL 5.4 from MySQL 5.1
There are Several variables and options are new or changed in MySQL 5.4 to provide more flexible runtime configuration, and better “out of box” configuration of default values for MySQL operation on up to 16-way x86 servers and 64-way CMT servers with 4GB or more memory.
The changes to
InnoDB configuration values may cause issues if you upgrade to MySQL 5.4 from an older version or MySQL, or if you upgrade from MySQL 5.4.0 through 5.4.2 to 5.4.3 or higher. See Section 220.127.116.11, “Upgrading from MySQL 5.1 to 5.4”.
These system variables are new:
innodb_adaptive_flushing: Controls adaptive flushing of dirty pages. Default:
innodb_change_buffering: Controls insert buffering. Default:
inserts(buffer insert operations).
innodb_file_format: The format for new InnoDB tables. Default:
innodb_file_format_check: Whether to perform file format compatibility checking. Default:
innodb_io_capacity: The limit on the maximum number of I/O operations per second (IOPS) the server can perform. Default: 200.
innodb_read_ahead_threshold: Controls sensitivity of linear read-ahead. Default: 56.
innodb_replication_delay: The replication thread delay (in ms) on the slave server if
innodb_thread_concurrencyis reached. Default: 0.
innodb_write_io_threads: The number of background I/O threads to use for read prefetch requests and for writing dirty pages from the buffer cache to disk. Default: 4.
innodb_spin_wait_delay: Maximum delay between polls for a spin lock. Default: 6.
innodb_stats_sample_pages: How many index pages to sample for statistics calculations. Default: 8.
innodb_strict_mode: Whether InnoDB returns errors rather than warnings for certain exceptional conditions (analogous to strict SQL mode). Default:
innodb_use_sys_malloc: Whether InnoDB uses the OS (system) or its own memory allocator. Default:
innodb_version: The version of InnoDB.
More information about the new system variables can be found in the
InnoDB Plugin Manual at http://www.innodb.com/products/innodb_plugin/plugin-documentation.
The default or minimum value of these existing system variables has changed:
innodb_additional_mem_pool_size: Default increased from 1MB to 8MB.
innodb_buffer_pool_size: Default increased from 8 MB to 128MB. Minimum increased from 1MB to 5MB.
innodb_file_io_threads: Removed (replaced by
innodb_log_buffer_size: Default increased from 1MB to 8MB.
innodb_max_dirty_pages_pct: Default decreased from 90 to 75. Maximum decreased from 100 to 99 to never allow a completely dirty buffer pool.
innodb_sync_spin_loops: Default changed from 20 to 30.
innodb_thread_concurrency: Default changed from 8 to 0. In effect, this changes concurrency from 8 to “infinite”.
table_definition_cache: Default and minimum increased from 256 to 400.
table_open_cache: Default increased from 64 to 400.
These system variables have been made dynamic and can be modified at runtime:
This status variable is new:
Innodb_have_atomic_builtins: Indicates whether the server was built with atomic instructions.
This server option is new:
--super-large-pages: Boolean option. Large page support is enhanced for recent SPARC platforms. Standard use of large pages in MySQL attempts to use the largest size supported, up to 4MB. Under Solaris, a “super large pages” feature enables uses of pages up to 256MB. This feature can be enabled or disabled by using the
The acronym SEQUEL was later shortened to SQL because SEQUEL was a trademarked name; this means that the correct pronunciation of SQL is sequel not es-que-el (The 1995 SQL Reunion: People, Projects, and Politics). …
The scripts below and the video capture walkthrough setting up a Microsoft SQL Server Replication Distributor using SQL commands. As discussed in previous posting, the Distributor is a key role in Replication. …
We are currently seeking a Java PL/ SQL Developer for our client in the Consulting domain. We value our professionals, providing comprehensive benefits, exciting challenges, and the opportunity for growth. This is a contract position …
SQL Server Access Database Functions. … Default Re: SQL Server. —— Register to get rid of these "In Post" ads! —— The answer is yes SQL Express is the version you want. I'm not sure that it's available as a download anymore. …
So a lot of my customers and partners have been asking me about numbers around SQL Server, so I thought of getting this quick blog post up to show you an aggregate view of some of those articles – Thanks to Mark and Sunny for helping me …
This is SQL Injection Attacks. The main trend Firewall currently will not alarm when there is SQL attack because of the SQL Injection is via normal point and hidden and difficult to be detected, seemingly normal website visit. …
Database management systems are among the most important software systems for businesses in the information age. SQL Server enterprise level RDBMS provided by.
the SQL Developer Migration Workbench does not yet include online migrations of SQL Server 2008 (maximum version is 2005) to Oracle 11g. …
Malicious hackers are relying on growing numbers of increasingly complex SQL attacks to get at companies' data. The SQL injection is hardly a new attack …
See all stories on this topic