Innodb_thread_concurrency

1. What value is best for Innodb_thread_concurrency?
2. What is Innodb_thread_concurrency in MySQL?
3. What is Innodb_write_io_threads?
4. What is Innodb_stats_persistent_sample_pages?
5. How many threads can MySQL handle?
6. Does MySQL support concurrency?
7. What is Innodb_file_per_table?
8. What is Innodb_flush_method?
9. What is Log_bin_trust_function_creators?
10. What is Innodb_adaptive_hash_index?
11. What is Innodb_data_file_path?
12. What is Innodb_flush_log_at_trx_commit?
13. What is innodb_buffer_pool_size?

What value is best for Innodb_thread_concurrency?

innodb_thread_concurrency. With improvements to the InnoDB engine, it is recommended to allow the engine to control the concurrency by keeping it to default value (which is zero). If you see concurrency issues, you can tune this variable. A recommended value is 2 times the number of CPUs plus the number of disks.

What is Innodb_thread_concurrency in MySQL?

By default, innodb_thread_concurrency is 0. That's actually the best setting. It means infinite concurrency. It allows the InnoDB storage engine to decide the best number of concurrency tickets to launch and address. Setting it to a nonzero value actually can throttle InnoDB or throttle the OS if not set properly.

What is Innodb_write_io_threads?

innodb_write_io_threads. The number of I/O threads for write operations in InnoDB. The default value is 4.

What is Innodb_stats_persistent_sample_pages?

innodb_stats_persistent_sample_pages. It is used for number of index pages to sample when estimating cardinality and other statistics for an indexed column.

How many threads can MySQL handle?

The maximum number of threads per group is 4096 (or 4095 on some systems where one thread is used internally). The thread pool separates connections and threads, so there is no fixed relationship between connections and the threads that execute statements received from those connections.

Does MySQL support concurrency?

Multiversion Concurrency Control. Most of MySQL's transactional storage engines, such as InnoDB, Falcon, and PBXT, don't use a simple row-locking mechanism. Instead, they use row-level locking in conjunction with a technique for increasing concurrency known as multiversion concurrency control (MVCC).

What is Innodb_file_per_table?

InnoDB creates tables in file-per-table tablespaces by default. This behavior is controlled by the innodb_file_per_table variable. Disabling innodb_file_per_table causes InnoDB to create tables in the system tablespace. ... innodb_file_per_table is enabled by default in MySQL 5.6 and higher.

What is Innodb_flush_method?

innodb_flush_method variable specifies how InnoDB opens and flushes log and data files. ... If innodb_flush_method is set to O_DIRECT it'd avoid double buffering and reduce swap pressure and helps improving performance.

What is Log_bin_trust_function_creators?

log_bin_trust_function_creators. This variable applies when binary logging is enabled. The best approach is a better understanding and use of deterministic declarations for stored functions.

What is Innodb_adaptive_hash_index?

The adaptive hash index is enabled by the innodb_adaptive_hash_index variable, or turned off at server startup by --skip-innodb-adaptive-hash-index . Based on the observed pattern of searches, a hash index is built using a prefix of the index key. ... InnoDB has a mechanism that monitors index searches.

What is Innodb_data_file_path?

By default, a single system tablespace data file, named ibdata1 , is created in the data directory. The size and number of system tablespace data files is defined by the innodb_data_file_path startup option. For configuration information, see System Tablespace Data File Configuration.

What is Innodb_flush_log_at_trx_commit?

Description. InnoDB will regularly flush logs to the disk. ... If innodb_flush_log_at_trx_commit is set to 0, the log buffer is written out to the log file once per second and the flush to disk operation is performed on the log file. However, nothing is done at a transaction commit.

What is innodb_buffer_pool_size?

innodb_buffer_pool_size is the MySQL configuration parameter that specifies the amount of memory allocated to the InnoDB buffer pool by MySQL. This is one of the most important settings in the MySQL hosting configuration and should be configured based on the available system RAM.