C.1. New Parameters

Throughout the course of development, the InnoDB Plugin has introduced new configuration parameters. The following table summarizes those parameters:

Table C.1. InnoDB Plugin New Parameter Summary

NameCmd-LineOption FileSystem VarScopeDynamicDefault
innodb_adaptive_flushingYESYESYESGLOBALYESTRUE
innodb_change_bufferingYESYESYESGLOBALYESinserts
innodb_file_formatYESYESYESGLOBALYESAntelope
innodb_file_format_checkYESYESYESGLOBALYESON
innodb_io_capacityYESYESYESGLOBALYES200
innodb_old_blocks_pctYESYESYESGLOBALYES37
innodb_old_blocks_timeYESYESYESGLOBALYES0
innodb_read_ahead_thresholdYESYESYESGLOBALYES56
innodb_read_io_threadsYESYESYESGLOBALNO4
innodb_spin_wait_delayYESYESYESGLOBALYES6
innodb_stats_sample_pagesYESYESYESGLOBALYES8
innodb_strict_modeYESYESYESGLOBAL|SESSIONYESFALSE
innodb_use_sys_mallocYESYESYESGLOBALNOTRUE
innodb_write_io_threadsYESYESYESGLOBALNO4

innodb_adaptive_flushing

Whether InnoDB uses a new algorithm to estimate the required rate of flushing. The default value is TRUE. This parameter was added in InnoDB Plugin 1.0.4. See Section 7.11, “Controlling the Flushing Rate of Dirty Pages” for more information.

innodb_change_buffering

Whether InnoDB performs insert buffering. The default value is "inserts" (buffer insert operations). This parameter was added in InnoDB Plugin 1.0.3. See Section 7.4, “Controlling InnoDB Insert Buffering” for more information.

innodb_file_format

Whether to enable the new Barracuda file format. The default value is Antelope. This parameter was added in InnoDB Plugin 1.0.1. See Section 4.3, “Enabling File Formats” for more information.

innodb_file_format_check

Whether InnoDB performs file format compatibility checking when opening a database. The default value is ON. This parameter was added in InnoDB Plugin 1.0.1. See Section 4.4.1, “Startup File Format Compatibility Checking” for more information.

innodb_io_capacity

The number of I/O operations that can be performed per second. The allowable value range is any number 100 or greater, and the default value is 200. This parameter was added in InnoDB Plugin 1.0.4. To reproduce the earlier behavior, use a value of 100. See Section 7.10, “Controlling the Master Thread I/O Rate” for more information.

innodb_old_blocks_pct

Controls the desired percentage of old blocks in the LRU list of the buffer pool. The default value is 37 and the allowable value range is 5 to 95. This parameter was added in InnoDB Plugin 1.0.5. See Section 7.14, “Making Buffer Cache Scan Resistant” for more information.

innodb_old_blocks_time

The time in milliseconds since the first access to a block during which it can be accessed again without being made young. The default value is 0 which means that blocks are moved to the young end of the LRU list at the first access. This parameter was added in InnoDB Plugin 1.0.5. See Section 7.14, “Making Buffer Cache Scan Resistant” for more information.

innodb_read_ahead_threshold

Control the sensitivity of the linear read ahead. The allowable value range is 0 to 64 and the default value is 56. This parameter was added in InnoDB Plugin 1.0.4. See Section 7.7, “Changes in the Read Ahead Algorithm” for more information.

innodb_read_io_threads

The number of background I/O threads used for reads. The allowable value range is 1 to 64 and the default value is 4. This parameter was added in InnoDB Plugin 1.0.4. See Section 7.8, “Multiple Background I/O Threads” for more information.

innodb_spin_wait_delay

Maximum delay between polling for a spin lock. The allowable value range is 0 (meaning unlimited) or positive integers and the default value is 6. This parameter was added in InnoDB Plugin 1.0.4. See Section 7.13, “Control of Spin Lock Polling” for more information.

innodb_stats_sample_pages

The number of index pages to sample when calculating statistics. The allowable value range is 1-unlimited and the default value is 8. This parameter was added in InnoDB Plugin 1.0.2. See Section 8.6, “Controlling Optimizer Statistics Estimation” for more information.

innodb_strict_mode

Whether InnoDB raises error conditions in certain cases, rather than issuing a warning. The default value is OFF. This parameter was added in InnoDB Plugin 1.0.2. See Section 8.5, “InnoDB Strict Mode” for more information.

innodb_use_sys_malloc

Whether InnoDB uses its own memory allocator or an allocator of the operating system. The default value is ON (use an allocator of the underlying system). This parameter was added in InnoDB Plugin 1.0.3. See Section 7.3, “Using Operating System Memory Allocators” for more information.

innodb_write_io_threads

The number of background I/O threads used for writes. The allowable value range is 1 to 64 and the default value is 4. This parameter was added in InnoDB Plugin 1.0.4. See Section 7.8, “Multiple Background I/O Threads” for more information.


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