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mariadb/mysql-test/suite/sys_vars/r/sysvars_innodb.result
Marko Mäkelä 685d958e38 MDEV-14425 Improve the redo log for concurrency 
The InnoDB redo log used to be formatted in blocks of 512 bytes.
The log blocks were encrypted and the checksum was calculated while
holding log_sys.mutex, creating a serious scalability bottleneck.

We remove the fixed-size redo log block structure altogether and
essentially turn every mini-transaction into a log block of its own.
This allows encryption and checksum calculations to be performed
on local mtr_t::m_log buffers, before acquiring log_sys.mutex.
The mutex only protects a memcpy() of the data to the shared
log_sys.buf, as well as the padding of the log, in case the
to-be-written part of the log would not end in a block boundary of
the underlying storage. For now, the "padding" consists of writing
a single NUL byte, to allow recovery and mariadb-backup to detect
the end of the circular log faster.

Like the previous implementation, we will overwrite the last log block
over and over again, until it has been completely filled. It would be
possible to write only up to the last completed block (if no more
recent write was requested), or to write dummy FILE_CHECKPOINT records
to fill the incomplete block, by invoking the currently disabled
function log_pad(). This would require adjustments to some logic around
log checkpoints, page flushing, and shutdown.

An upgrade after a crash of any previous version is not supported.
Logically empty log files from a previous version will be upgraded.

An attempt to start up InnoDB without a valid ib_logfile0 will be
refused. Previously, the redo log used to be created automatically
if it was missing. Only with with innodb_force_recovery=6, it is
possible to start InnoDB in read-only mode even if the log file
does not exist. This allows the contents of a possibly corrupted
database to be dumped.

Because a prepared backup from an earlier version of mariadb-backup
will create a 0-sized log file, we will allow an upgrade from such
log files, provided that the FIL_PAGE_FILE_FLUSH_LSN in the system
tablespace looks valid.

The 512-byte log checkpoint blocks at 0x200 and 0x600 will be replaced
with 64-byte log checkpoint blocks at 0x1000 and 0x2000.

The start of log records will move from 0x800 to 0x3000. This allows us
to use 4096-byte aligned blocks for all I/O in a future revision.

We extend the MDEV-12353 redo log record format as follows.

(1) Empty mini-transactions or extra NUL bytes will not be allowed.
(2) The end-of-minitransaction marker (a NUL byte) will be replaced
with a 1-bit sequence number, which will be toggled each time when the
circular log file wraps back to the beginning.
(3) After the sequence bit, a CRC-32C checksum of all data
(excluding the sequence bit) will written.
(4) If the log is encrypted, 8 bytes will be written before
the checksum and included in it. This is part of the
initialization vector (IV) of encrypted log data.
(5) File names, page numbers, and checkpoint information will not be
encrypted. Only the payload bytes of page-level log will be encrypted.
The tablespace ID and page number will form part of the IV.
(6) For padding, arbitrary-length FILE_CHECKPOINT records may be written,
with all-zero payload, and with the normal end marker and checksum.
The minimum size is 7 bytes, or 7+8 with innodb_encrypt_log=ON.

In mariadb-backup and in Galera snapshot transfer (SST) scripts, we will
no longer remove ib_logfile0 or create an empty ib_logfile0. Server startup
will require a valid log file. When resizing the log, we will create
a logically empty ib_logfile101 at the current LSN and use an atomic rename
to replace ib_logfile0 with it. See the test innodb.log_file_size.

Because there is no mandatory padding in the log file, we are able
to create a dummy log file as of an arbitrary log sequence number.
See the test mariabackup.huge_lsn.

The parameter innodb_log_write_ahead_size and the
INFORMATION_SCHEMA.INNODB_METRICS counter log_padded will be removed.

The minimum value of innodb_log_buffer_size will be increased to 2MiB
(because log_sys.buf will replace recv_sys.buf) and the increment
adjusted to 4096 bytes (the maximum log block size).

The following INFORMATION_SCHEMA.INNODB_METRICS counters will be removed:

os_log_fsyncs
os_log_pending_fsyncs
log_pending_log_flushes
log_pending_checkpoint_writes

The following status variables will be removed:

Innodb_os_log_fsyncs (this is included in Innodb_data_fsyncs)
Innodb_os_log_pending_fsyncs (this was limited to at most 1 by design)

log_sys.get_block_size(): Return the physical block size of the log file.
This is only implemented on Linux and Microsoft Windows for now, and for
the power-of-2 block sizes between 64 and 4096 bytes (the minimum and
maximum size of a checkpoint block). If the block size is anything else,
the traditional 512-byte size will be used via normal file system
buffering.

If the file system buffers can be bypassed, a message like the following
will be issued:

InnoDB: File system buffers for log disabled (block size=512 bytes)
InnoDB: File system buffers for log disabled (block size=4096 bytes)

This has been tested on Linux and Microsoft Windows with both sizes.

On Linux, only enable O_DIRECT on the log for innodb_flush_method=O_DSYNC.
Tests in 3 different environments where the log is stored in a device
with a physical block size of 512 bytes are yielding better throughput
without O_DIRECT. This could be due to the fact that in the event the
last log block is being overwritten (if multiple transactions would
become durable at the same time, and each of will write a small
number of bytes to the last log block), it should be faster to re-copy
data from log_sys.buf or log_sys.flush_buf to the kernel buffer,
to be finally written at fdatasync() time.

The parameter innodb_flush_method=O_DSYNC will imply O_DIRECT for
data files. This option will enable O_DIRECT on the log file on Linux.
It may be unsafe to use when the storage device does not support
FUA (Force Unit Access) mode.

When the server is compiled WITH_PMEM=ON, we will use memory-mapped
I/O for the log file if the log resides on a "mount -o dax" device.
We will identify PMEM in a start-up message:

InnoDB: log sequence number 0 (memory-mapped); transaction id 3

On Linux, we will also invoke mmap() on any ib_logfile0 that resides
in /dev/shm, effectively treating the log file as persistent memory.
This should speed up "./mtr --mem" and increase the test coverage of
PMEM on non-PMEM hardware. It also allows users to estimate how much
the performance would be improved by installing persistent memory.
On other tmpfs file systems such as /run, we will not use mmap().

mariadb-backup: Eliminated several variables. We will refer
directly to recv_sys and log_sys.

backup_wait_for_lsn(): Detect non-progress of
xtrabackup_copy_logfile(). In this new log format with
arbitrary-sized blocks, we can only detect log file overrun
indirectly, by observing that the scanned log sequence number
is not advancing.

xtrabackup_copy_logfile(): On PMEM, do not modify the sequence bit,
because we are not allowed to modify the server's log file, and our
memory mapping is read-only.

trx_flush_log_if_needed_low(): Do not use the callback on pmem.
Using neither flush_lock nor write_lock around PMEM writes seems
to yield the best performance. The pmem_persist() calls may
still be somewhat slower than the pwrite() and fdatasync() based
interface (PMEM mounted without -o dax).

recv_sys_t::buf: Remove. We will use log_sys.buf for parsing.

recv_sys_t::MTR_SIZE_MAX: Replaces RECV_SCAN_SIZE.

recv_sys_t::file_checkpoint: Renamed from mlog_checkpoint_lsn.

recv_sys_t, log_sys_t: Removed many data members.

recv_sys.lsn: Renamed from recv_sys.recovered_lsn.
recv_sys.offset: Renamed from recv_sys.recovered_offset.
log_sys.buf_size: Replaces srv_log_buffer_size.

recv_buf: A smart pointer that wraps log_sys.buf[recv_sys.offset]
when the buffer is being allocated from the memory heap.

recv_ring: A smart pointer that wraps a circular log_sys.buf[] that is
backed by ib_logfile0. The pointer will wrap from recv_sys.len
(log_sys.file_size) to log_sys.START_OFFSET. For the record that
wraps around, we may copy file name or record payload data to
the auxiliary buffer decrypt_buf in order to have a contiguous
block of memory. The maximum size of a record is less than
innodb_page_size bytes.

recv_sys_t::parse(): Take the smart pointer as a template parameter.
Do not temporarily add a trailing NUL byte to FILE_ records, because
we are not supposed to modify the memory-mapped log file. (It is
attached in read-write mode already during recovery.)

recv_sys_t::parse_mtr(): Wrapper for recv_sys_t::parse().

recv_sys_t::parse_pmem(): Like parse_mtr(), but if PREMATURE_EOF would be
returned on PMEM, use recv_ring to wrap around the buffer to the start.

mtr_t::finish_write(), log_close(): Do not enforce log_sys.max_buf_free
on PMEM, because it has no meaning on the mmap-based log.

log_sys.write_to_buf: Count writes to log_sys.buf. Replaces
srv_stats.log_write_requests and export_vars.innodb_log_write_requests.
Protected by log_sys.mutex. Updated consistently in log_close().
Previously, mtr_t::commit() conditionally updated the count,
which was inconsistent.

log_sys.write_to_log: Count swaps of log_sys.buf and log_sys.flush_buf,
for writing to log_sys.log (the ib_logfile0). Replaces
srv_stats.log_writes and export_vars.innodb_log_writes.
Protected by log_sys.mutex.

log_sys.waits: Count waits in append_prepare(). Replaces
srv_stats.log_waits and export_vars.innodb_log_waits.

recv_recover_page(): Do not unnecessarily acquire
log_sys.flush_order_mutex. We are inserting the blocks in arbitary
order anyway, to be adjusted in recv_sys.apply(true).

We will change the definition of flush_lock and write_lock to
avoid potential false sharing. Depending on sizeof(log_sys) and
CPU_LEVEL1_DCACHE_LINESIZE, the flush_lock and write_lock could
share a cache line with each other or with the last data members
of log_sys.

Thanks to Matthias Leich for providing https://rr-project.org traces
for various failures during the development, and to
Thirunarayanan Balathandayuthapani for his help in debugging
some of the recovery code. And thanks to the developers of the
rr debugger for a tool without which extensive changes to InnoDB
would be very challenging to get right.

Thanks to Vladislav Vaintroub for useful feedback and
to him, Axel Schwenke and Krunal Bauskar for testing the performance.
2022-01-21 16:03:47 +02:00

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select VARIABLE_NAME, SESSION_VALUE, DEFAULT_VALUE, VARIABLE_SCOPE, VARIABLE_TYPE, VARIABLE_COMMENT, NUMERIC_MIN_VALUE, NUMERIC_MAX_VALUE, NUMERIC_BLOCK_SIZE, ENUM_VALUE_LIST, READ_ONLY, COMMAND_LINE_ARGUMENT from information_schema.system_variables
where variable_name like 'innodb%' and
variable_name not in (
'innodb_version', # always the same as the server version
'innodb_disallow_writes', # only available WITH_WSREP
'innodb_numa_interleave', # only available WITH_NUMA
'innodb_sched_priority_cleaner', # linux only
'innodb_evict_tables_on_commit_debug', # one may want to override this
'innodb_use_native_aio', # default value depends on OS
'innodb_buffer_pool_load_pages_abort') # debug build only, and is only for testing
order by variable_name;
VARIABLE_NAME INNODB_ADAPTIVE_FLUSHING
SESSION_VALUE NULL
DEFAULT_VALUE ON
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BOOLEAN
VARIABLE_COMMENT Attempt flushing dirty pages to avoid IO bursts at checkpoints.
NUMERIC_MIN_VALUE NULL
NUMERIC_MAX_VALUE NULL
NUMERIC_BLOCK_SIZE NULL
ENUM_VALUE_LIST OFF,ON
READ_ONLY NO
COMMAND_LINE_ARGUMENT NONE
VARIABLE_NAME INNODB_ADAPTIVE_FLUSHING_LWM
SESSION_VALUE NULL
DEFAULT_VALUE 10.000000
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE DOUBLE
VARIABLE_COMMENT Percentage of log capacity below which no adaptive flushing happens.
NUMERIC_MIN_VALUE 0
NUMERIC_MAX_VALUE 70
NUMERIC_BLOCK_SIZE NULL
ENUM_VALUE_LIST NULL
READ_ONLY NO
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_ADAPTIVE_HASH_INDEX
SESSION_VALUE NULL
DEFAULT_VALUE OFF
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BOOLEAN
VARIABLE_COMMENT Enable InnoDB adaptive hash index (disabled by default).
NUMERIC_MIN_VALUE NULL
NUMERIC_MAX_VALUE NULL
NUMERIC_BLOCK_SIZE NULL
ENUM_VALUE_LIST OFF,ON
READ_ONLY NO
COMMAND_LINE_ARGUMENT OPTIONAL
VARIABLE_NAME INNODB_ADAPTIVE_HASH_INDEX_PARTS
SESSION_VALUE NULL
DEFAULT_VALUE 8
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BIGINT UNSIGNED
VARIABLE_COMMENT Number of InnoDB Adaptive Hash Index Partitions (default 8)
NUMERIC_MIN_VALUE 1
NUMERIC_MAX_VALUE 512
NUMERIC_BLOCK_SIZE 0
ENUM_VALUE_LIST NULL
READ_ONLY YES
COMMAND_LINE_ARGUMENT OPTIONAL
VARIABLE_NAME INNODB_AUTOEXTEND_INCREMENT
SESSION_VALUE NULL
DEFAULT_VALUE 64
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE INT UNSIGNED
VARIABLE_COMMENT Data file autoextend increment in megabytes
NUMERIC_MIN_VALUE 1
NUMERIC_MAX_VALUE 1000
NUMERIC_BLOCK_SIZE 0
ENUM_VALUE_LIST NULL
READ_ONLY NO
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_AUTOINC_LOCK_MODE
SESSION_VALUE NULL
DEFAULT_VALUE 1
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BIGINT
VARIABLE_COMMENT The AUTOINC lock modes supported by InnoDB: 0 => Old style AUTOINC locking (for backward compatibility); 1 => New style AUTOINC locking; 2 => No AUTOINC locking (unsafe for SBR)
NUMERIC_MIN_VALUE 0
NUMERIC_MAX_VALUE 2
NUMERIC_BLOCK_SIZE 0
ENUM_VALUE_LIST NULL
READ_ONLY YES
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_BUFFER_POOL_CHUNK_SIZE
SESSION_VALUE NULL
DEFAULT_VALUE 0
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BIGINT UNSIGNED
VARIABLE_COMMENT Size of a single memory chunk for resizing buffer pool. Online buffer pool resizing happens at this granularity. 0 means autosize this variable based on buffer pool size.
NUMERIC_MIN_VALUE 0
NUMERIC_MAX_VALUE 18446744073709551615
NUMERIC_BLOCK_SIZE 1048576
ENUM_VALUE_LIST NULL
READ_ONLY YES
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_BUFFER_POOL_DUMP_AT_SHUTDOWN
SESSION_VALUE NULL
DEFAULT_VALUE ON
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BOOLEAN
VARIABLE_COMMENT Dump the buffer pool into a file named @@innodb_buffer_pool_filename
NUMERIC_MIN_VALUE NULL
NUMERIC_MAX_VALUE NULL
NUMERIC_BLOCK_SIZE NULL
ENUM_VALUE_LIST OFF,ON
READ_ONLY NO
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_BUFFER_POOL_DUMP_NOW
SESSION_VALUE NULL
DEFAULT_VALUE OFF
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BOOLEAN
VARIABLE_COMMENT Trigger an immediate dump of the buffer pool into a file named @@innodb_buffer_pool_filename
NUMERIC_MIN_VALUE NULL
NUMERIC_MAX_VALUE NULL
NUMERIC_BLOCK_SIZE NULL
ENUM_VALUE_LIST OFF,ON
READ_ONLY NO
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_BUFFER_POOL_DUMP_PCT
SESSION_VALUE NULL
DEFAULT_VALUE 25
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BIGINT UNSIGNED
VARIABLE_COMMENT Dump only the hottest N% of each buffer pool, defaults to 25
NUMERIC_MIN_VALUE 1
NUMERIC_MAX_VALUE 100
NUMERIC_BLOCK_SIZE 0
ENUM_VALUE_LIST NULL
READ_ONLY NO
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_BUFFER_POOL_EVICT
SESSION_VALUE NULL
DEFAULT_VALUE
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE VARCHAR
VARIABLE_COMMENT Evict pages from the buffer pool
NUMERIC_MIN_VALUE NULL
NUMERIC_MAX_VALUE NULL
NUMERIC_BLOCK_SIZE NULL
ENUM_VALUE_LIST NULL
READ_ONLY NO
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_BUFFER_POOL_FILENAME
SESSION_VALUE NULL
DEFAULT_VALUE ib_buffer_pool
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE VARCHAR
VARIABLE_COMMENT Filename to/from which to dump/load the InnoDB buffer pool
NUMERIC_MIN_VALUE NULL
NUMERIC_MAX_VALUE NULL
NUMERIC_BLOCK_SIZE NULL
ENUM_VALUE_LIST NULL
READ_ONLY NO
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_BUFFER_POOL_LOAD_ABORT
SESSION_VALUE NULL
DEFAULT_VALUE OFF
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BOOLEAN
VARIABLE_COMMENT Abort a currently running load of the buffer pool
NUMERIC_MIN_VALUE NULL
NUMERIC_MAX_VALUE NULL
NUMERIC_BLOCK_SIZE NULL
ENUM_VALUE_LIST OFF,ON
READ_ONLY NO
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_BUFFER_POOL_LOAD_AT_STARTUP
SESSION_VALUE NULL
DEFAULT_VALUE ON
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BOOLEAN
VARIABLE_COMMENT Load the buffer pool from a file named @@innodb_buffer_pool_filename
NUMERIC_MIN_VALUE NULL
NUMERIC_MAX_VALUE NULL
NUMERIC_BLOCK_SIZE NULL
ENUM_VALUE_LIST OFF,ON
READ_ONLY YES
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_BUFFER_POOL_LOAD_NOW
SESSION_VALUE NULL
DEFAULT_VALUE OFF
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BOOLEAN
VARIABLE_COMMENT Trigger an immediate load of the buffer pool from a file named @@innodb_buffer_pool_filename
NUMERIC_MIN_VALUE NULL
NUMERIC_MAX_VALUE NULL
NUMERIC_BLOCK_SIZE NULL
ENUM_VALUE_LIST OFF,ON
READ_ONLY NO
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_BUFFER_POOL_SIZE
SESSION_VALUE NULL
DEFAULT_VALUE 134217728
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BIGINT UNSIGNED
VARIABLE_COMMENT The size of the memory buffer InnoDB uses to cache data and indexes of its tables.
NUMERIC_MIN_VALUE 5242880
NUMERIC_MAX_VALUE 9223372036854775807
NUMERIC_BLOCK_SIZE 1048576
ENUM_VALUE_LIST NULL
READ_ONLY NO
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_BUF_DUMP_STATUS_FREQUENCY
SESSION_VALUE NULL
DEFAULT_VALUE 0
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BIGINT UNSIGNED
VARIABLE_COMMENT A number between [0, 100] that tells how oftern buffer pool dump status in percentages should be printed. E.g. 10 means that buffer pool dump status is printed when every 10% of number of buffer pool pages are dumped. Default is 0 (only start and end status is printed).
NUMERIC_MIN_VALUE 0
NUMERIC_MAX_VALUE 100
NUMERIC_BLOCK_SIZE 0
ENUM_VALUE_LIST NULL
READ_ONLY NO
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_BUF_FLUSH_LIST_NOW
SESSION_VALUE NULL
DEFAULT_VALUE OFF
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BOOLEAN
VARIABLE_COMMENT Force dirty page flush now
NUMERIC_MIN_VALUE NULL
NUMERIC_MAX_VALUE NULL
NUMERIC_BLOCK_SIZE NULL
ENUM_VALUE_LIST OFF,ON
READ_ONLY NO
COMMAND_LINE_ARGUMENT OPTIONAL
VARIABLE_NAME INNODB_CHANGE_BUFFERING
SESSION_VALUE NULL
DEFAULT_VALUE all
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE ENUM
VARIABLE_COMMENT Buffer changes to secondary indexes.
NUMERIC_MIN_VALUE NULL
NUMERIC_MAX_VALUE NULL
NUMERIC_BLOCK_SIZE NULL
ENUM_VALUE_LIST none,inserts,deletes,changes,purges,all
READ_ONLY NO
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_CHANGE_BUFFERING_DEBUG
SESSION_VALUE NULL
DEFAULT_VALUE 0
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE INT UNSIGNED
VARIABLE_COMMENT Debug flags for InnoDB change buffering (0=none, 1=try to buffer)
NUMERIC_MIN_VALUE 0
NUMERIC_MAX_VALUE 1
NUMERIC_BLOCK_SIZE 0
ENUM_VALUE_LIST NULL
READ_ONLY NO
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_CHANGE_BUFFER_DUMP
SESSION_VALUE NULL
DEFAULT_VALUE OFF
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BOOLEAN
VARIABLE_COMMENT Dump the change buffer at startup.
NUMERIC_MIN_VALUE NULL
NUMERIC_MAX_VALUE NULL
NUMERIC_BLOCK_SIZE NULL
ENUM_VALUE_LIST OFF,ON
READ_ONLY YES
COMMAND_LINE_ARGUMENT NONE
VARIABLE_NAME INNODB_CHANGE_BUFFER_MAX_SIZE
SESSION_VALUE NULL
DEFAULT_VALUE 25
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE INT UNSIGNED
VARIABLE_COMMENT Maximum on-disk size of change buffer in terms of percentage of the buffer pool.
NUMERIC_MIN_VALUE 0
NUMERIC_MAX_VALUE 50
NUMERIC_BLOCK_SIZE 0
ENUM_VALUE_LIST NULL
READ_ONLY NO
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_CHECKSUM_ALGORITHM
SESSION_VALUE NULL
DEFAULT_VALUE full_crc32
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE ENUM
VARIABLE_COMMENT The algorithm InnoDB uses for page checksumming. Possible values are FULL_CRC32 for new files, always use CRC-32C; for old, see CRC32 below; STRICT_FULL_CRC32 for new files, always use CRC-32C; for old, see STRICT_CRC32 below; CRC32 write crc32, allow any of the other checksums to match when reading; STRICT_CRC32 write crc32, do not allow other algorithms to match when reading; INNODB write a software calculated checksum, allow any other checksums to match when reading; STRICT_INNODB write a software calculated checksum, do not allow other algorithms to match when reading; NONE write a constant magic number, do not do any checksum verification when reading; STRICT_NONE write a constant magic number, do not allow values other than that magic number when reading; Files updated when this option is set to crc32 or strict_crc32 will not be readable by MariaDB versions older than 10.0.4; new files created with full_crc32 are readable by MariaDB 10.4.3+
NUMERIC_MIN_VALUE NULL
NUMERIC_MAX_VALUE NULL
NUMERIC_BLOCK_SIZE NULL
ENUM_VALUE_LIST crc32,strict_crc32,full_crc32,strict_full_crc32
READ_ONLY NO
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_CMP_PER_INDEX_ENABLED
SESSION_VALUE NULL
DEFAULT_VALUE OFF
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BOOLEAN
VARIABLE_COMMENT Enable INFORMATION_SCHEMA.innodb_cmp_per_index, may have negative impact on performance (off by default)
NUMERIC_MIN_VALUE NULL
NUMERIC_MAX_VALUE NULL
NUMERIC_BLOCK_SIZE NULL
ENUM_VALUE_LIST OFF,ON
READ_ONLY NO
COMMAND_LINE_ARGUMENT OPTIONAL
VARIABLE_NAME INNODB_COMPRESSION_ALGORITHM
SESSION_VALUE NULL
DEFAULT_VALUE zlib
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE ENUM
VARIABLE_COMMENT Compression algorithm used on page compression. One of: none, zlib, lz4, lzo, lzma, bzip2, or snappy
NUMERIC_MIN_VALUE NULL
NUMERIC_MAX_VALUE NULL
NUMERIC_BLOCK_SIZE NULL
ENUM_VALUE_LIST none,zlib,lz4,lzo,lzma,bzip2,snappy
READ_ONLY NO
COMMAND_LINE_ARGUMENT OPTIONAL
VARIABLE_NAME INNODB_COMPRESSION_DEFAULT
SESSION_VALUE OFF
DEFAULT_VALUE OFF
VARIABLE_SCOPE SESSION
VARIABLE_TYPE BOOLEAN
VARIABLE_COMMENT Is compression the default for new tables
NUMERIC_MIN_VALUE NULL
NUMERIC_MAX_VALUE NULL
NUMERIC_BLOCK_SIZE NULL
ENUM_VALUE_LIST OFF,ON
READ_ONLY NO
COMMAND_LINE_ARGUMENT OPTIONAL
VARIABLE_NAME INNODB_COMPRESSION_FAILURE_THRESHOLD_PCT
SESSION_VALUE NULL
DEFAULT_VALUE 5
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BIGINT UNSIGNED
VARIABLE_COMMENT If the compression failure rate of a table is greater than this number more padding is added to the pages to reduce the failures. A value of zero implies no padding
NUMERIC_MIN_VALUE 0
NUMERIC_MAX_VALUE 100
NUMERIC_BLOCK_SIZE 0
ENUM_VALUE_LIST NULL
READ_ONLY NO
COMMAND_LINE_ARGUMENT OPTIONAL
VARIABLE_NAME INNODB_COMPRESSION_LEVEL
SESSION_VALUE NULL
DEFAULT_VALUE 6
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE INT UNSIGNED
VARIABLE_COMMENT Compression level used for zlib compression. 0 is no compression, 1 is fastest, 9 is best compression and default is 6.
NUMERIC_MIN_VALUE 0
NUMERIC_MAX_VALUE 9
NUMERIC_BLOCK_SIZE 0
ENUM_VALUE_LIST NULL
READ_ONLY NO
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_COMPRESSION_PAD_PCT_MAX
SESSION_VALUE NULL
DEFAULT_VALUE 50
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BIGINT UNSIGNED
VARIABLE_COMMENT Percentage of empty space on a data page that can be reserved to make the page compressible.
NUMERIC_MIN_VALUE 0
NUMERIC_MAX_VALUE 75
NUMERIC_BLOCK_SIZE 0
ENUM_VALUE_LIST NULL
READ_ONLY NO
COMMAND_LINE_ARGUMENT OPTIONAL
VARIABLE_NAME INNODB_DATA_FILE_PATH
SESSION_VALUE NULL
DEFAULT_VALUE ibdata1:12M:autoextend
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE VARCHAR
VARIABLE_COMMENT Path to individual files and their sizes.
NUMERIC_MIN_VALUE NULL
NUMERIC_MAX_VALUE NULL
NUMERIC_BLOCK_SIZE NULL
ENUM_VALUE_LIST NULL
READ_ONLY YES
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_DATA_FILE_SIZE_DEBUG
SESSION_VALUE NULL
DEFAULT_VALUE 0
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE INT UNSIGNED
VARIABLE_COMMENT InnoDB system tablespace size to be set in recovery.
NUMERIC_MIN_VALUE 0
NUMERIC_MAX_VALUE 268435456
NUMERIC_BLOCK_SIZE 0
ENUM_VALUE_LIST NULL
READ_ONLY YES
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_DATA_HOME_DIR
SESSION_VALUE NULL
DEFAULT_VALUE
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE VARCHAR
VARIABLE_COMMENT The common part for InnoDB table spaces.
NUMERIC_MIN_VALUE NULL
NUMERIC_MAX_VALUE NULL
NUMERIC_BLOCK_SIZE NULL
ENUM_VALUE_LIST NULL
READ_ONLY YES
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_DEADLOCK_DETECT
SESSION_VALUE NULL
DEFAULT_VALUE ON
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BOOLEAN
VARIABLE_COMMENT Enable/disable InnoDB deadlock detector (default ON). if set to OFF, deadlock detection is skipped, and we rely on innodb_lock_wait_timeout in case of deadlock.
NUMERIC_MIN_VALUE NULL
NUMERIC_MAX_VALUE NULL
NUMERIC_BLOCK_SIZE NULL
ENUM_VALUE_LIST OFF,ON
READ_ONLY NO
COMMAND_LINE_ARGUMENT NONE
VARIABLE_NAME INNODB_DEADLOCK_REPORT
SESSION_VALUE NULL
DEFAULT_VALUE full
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE ENUM
VARIABLE_COMMENT How to report deadlocks (if innodb_deadlock_detect=ON).
NUMERIC_MIN_VALUE NULL
NUMERIC_MAX_VALUE NULL
NUMERIC_BLOCK_SIZE NULL
ENUM_VALUE_LIST off,basic,full
READ_ONLY NO
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_DEFAULT_ENCRYPTION_KEY_ID
SESSION_VALUE 1
DEFAULT_VALUE 1
VARIABLE_SCOPE SESSION
VARIABLE_TYPE INT UNSIGNED
VARIABLE_COMMENT Default encryption key id used for table encryption.
NUMERIC_MIN_VALUE 1
NUMERIC_MAX_VALUE 4294967295
NUMERIC_BLOCK_SIZE 0
ENUM_VALUE_LIST NULL
READ_ONLY NO
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_DEFAULT_ROW_FORMAT
SESSION_VALUE NULL
DEFAULT_VALUE dynamic
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE ENUM
VARIABLE_COMMENT The default ROW FORMAT for all innodb tables created without explicit ROW_FORMAT. Possible values are REDUNDANT, COMPACT, and DYNAMIC. The ROW_FORMAT value COMPRESSED is not allowed
NUMERIC_MIN_VALUE NULL
NUMERIC_MAX_VALUE NULL
NUMERIC_BLOCK_SIZE NULL
ENUM_VALUE_LIST redundant,compact,dynamic
READ_ONLY NO
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_DEFRAGMENT
SESSION_VALUE NULL
DEFAULT_VALUE OFF
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BOOLEAN
VARIABLE_COMMENT Enable/disable InnoDB defragmentation (default FALSE). When set to FALSE, all existing defragmentation will be paused. And new defragmentation command will fail.Paused defragmentation commands will resume when this variable is set to true again.
NUMERIC_MIN_VALUE NULL
NUMERIC_MAX_VALUE NULL
NUMERIC_BLOCK_SIZE NULL
ENUM_VALUE_LIST OFF,ON
READ_ONLY NO
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_DEFRAGMENT_FILL_FACTOR
SESSION_VALUE NULL
DEFAULT_VALUE 0.900000
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE DOUBLE
VARIABLE_COMMENT A number between [0.7, 1] that tells defragmentation how full it should fill a page. Default is 0.9. Number below 0.7 won't make much sense.This variable, together with innodb_defragment_fill_factor_n_recs, is introduced so defragmentation won't pack the page too full and cause page split on the next insert on every page. The variable indicating more defragmentation gain is the one effective.
NUMERIC_MIN_VALUE 0.7
NUMERIC_MAX_VALUE 1
NUMERIC_BLOCK_SIZE NULL
ENUM_VALUE_LIST NULL
READ_ONLY NO
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_DEFRAGMENT_FILL_FACTOR_N_RECS
SESSION_VALUE NULL
DEFAULT_VALUE 20
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE INT UNSIGNED
VARIABLE_COMMENT How many records of space defragmentation should leave on the page. This variable, together with innodb_defragment_fill_factor, is introduced so defragmentation won't pack the page too full and cause page split on the next insert on every page. The variable indicating more defragmentation gain is the one effective.
NUMERIC_MIN_VALUE 1
NUMERIC_MAX_VALUE 100
NUMERIC_BLOCK_SIZE 0
ENUM_VALUE_LIST NULL
READ_ONLY NO
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_DEFRAGMENT_FREQUENCY
SESSION_VALUE NULL
DEFAULT_VALUE 40
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE INT UNSIGNED
VARIABLE_COMMENT Do not defragment a single index more than this number of time per second.This controls the number of time defragmentation thread can request X_LOCK on an index. Defragmentation thread will check whether 1/defragment_frequency (s) has passed since it worked on this index last time, and put the index back to the queue if not enough time has passed. The actual frequency can only be lower than this given number.
NUMERIC_MIN_VALUE 1
NUMERIC_MAX_VALUE 1000
NUMERIC_BLOCK_SIZE 0
ENUM_VALUE_LIST NULL
READ_ONLY NO
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_DEFRAGMENT_N_PAGES
SESSION_VALUE NULL
DEFAULT_VALUE 7
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE INT UNSIGNED
VARIABLE_COMMENT Number of pages considered at once when merging multiple pages to defragment
NUMERIC_MIN_VALUE 2
NUMERIC_MAX_VALUE 32
NUMERIC_BLOCK_SIZE 0
ENUM_VALUE_LIST NULL
READ_ONLY NO
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_DEFRAGMENT_STATS_ACCURACY
SESSION_VALUE NULL
DEFAULT_VALUE 0
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE INT UNSIGNED
VARIABLE_COMMENT How many defragment stats changes there are before the stats are written to persistent storage. Set to 0 meaning disable defragment stats tracking.
NUMERIC_MIN_VALUE 0
NUMERIC_MAX_VALUE 4294967295
NUMERIC_BLOCK_SIZE 0
ENUM_VALUE_LIST NULL
READ_ONLY NO
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_DISABLE_SORT_FILE_CACHE
SESSION_VALUE NULL
DEFAULT_VALUE OFF
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BOOLEAN
VARIABLE_COMMENT Whether to disable OS system file cache for sort I/O
NUMERIC_MIN_VALUE NULL
NUMERIC_MAX_VALUE NULL
NUMERIC_BLOCK_SIZE NULL
ENUM_VALUE_LIST OFF,ON
READ_ONLY NO
COMMAND_LINE_ARGUMENT OPTIONAL
VARIABLE_NAME INNODB_DOUBLEWRITE
SESSION_VALUE NULL
DEFAULT_VALUE ON
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BOOLEAN
VARIABLE_COMMENT Enable InnoDB doublewrite buffer (enabled by default). Disable with --skip-innodb-doublewrite.
NUMERIC_MIN_VALUE NULL
NUMERIC_MAX_VALUE NULL
NUMERIC_BLOCK_SIZE NULL
ENUM_VALUE_LIST OFF,ON
READ_ONLY YES
COMMAND_LINE_ARGUMENT NONE
VARIABLE_NAME INNODB_ENCRYPTION_ROTATE_KEY_AGE
SESSION_VALUE NULL
DEFAULT_VALUE 1
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE INT UNSIGNED
VARIABLE_COMMENT Key rotation - re-encrypt in background all pages that were encrypted with a key that many (or more) versions behind. Value 0 indicates that key rotation is disabled.
NUMERIC_MIN_VALUE 0
NUMERIC_MAX_VALUE 4294967295
NUMERIC_BLOCK_SIZE 0
ENUM_VALUE_LIST NULL
READ_ONLY NO
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_ENCRYPTION_ROTATION_IOPS
SESSION_VALUE NULL
DEFAULT_VALUE 100
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE INT UNSIGNED
VARIABLE_COMMENT Use this many iops for background key rotation
NUMERIC_MIN_VALUE 0
NUMERIC_MAX_VALUE 4294967295
NUMERIC_BLOCK_SIZE 0
ENUM_VALUE_LIST NULL
READ_ONLY NO
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_ENCRYPTION_THREADS
SESSION_VALUE NULL
DEFAULT_VALUE 0
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE INT UNSIGNED
VARIABLE_COMMENT Number of threads performing background key rotation
NUMERIC_MIN_VALUE 0
NUMERIC_MAX_VALUE 255
NUMERIC_BLOCK_SIZE 0
ENUM_VALUE_LIST NULL
READ_ONLY NO
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_ENCRYPT_LOG
SESSION_VALUE NULL
DEFAULT_VALUE OFF
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BOOLEAN
VARIABLE_COMMENT Enable redo log encryption
NUMERIC_MIN_VALUE NULL
NUMERIC_MAX_VALUE NULL
NUMERIC_BLOCK_SIZE NULL
ENUM_VALUE_LIST OFF,ON
READ_ONLY YES
COMMAND_LINE_ARGUMENT OPTIONAL
VARIABLE_NAME INNODB_ENCRYPT_TABLES
SESSION_VALUE NULL
DEFAULT_VALUE OFF
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE ENUM
VARIABLE_COMMENT Enable encryption for tables. Don't forget to enable --innodb-encrypt-log too
NUMERIC_MIN_VALUE NULL
NUMERIC_MAX_VALUE NULL
NUMERIC_BLOCK_SIZE NULL
ENUM_VALUE_LIST OFF,ON,FORCE
READ_ONLY NO
COMMAND_LINE_ARGUMENT OPTIONAL
VARIABLE_NAME INNODB_ENCRYPT_TEMPORARY_TABLES
SESSION_VALUE NULL
DEFAULT_VALUE OFF
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BOOLEAN
VARIABLE_COMMENT Enrypt the temporary table data.
NUMERIC_MIN_VALUE NULL
NUMERIC_MAX_VALUE NULL
NUMERIC_BLOCK_SIZE NULL
ENUM_VALUE_LIST OFF,ON
READ_ONLY YES
COMMAND_LINE_ARGUMENT OPTIONAL
VARIABLE_NAME INNODB_FAST_SHUTDOWN
SESSION_VALUE NULL
DEFAULT_VALUE 1
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE INT UNSIGNED
VARIABLE_COMMENT Speeds up the shutdown process of the InnoDB storage engine. Possible values are 0, 1 (faster), 2 (crash-like), 3 (fastest clean).
NUMERIC_MIN_VALUE 0
NUMERIC_MAX_VALUE 3
NUMERIC_BLOCK_SIZE 0
ENUM_VALUE_LIST NULL
READ_ONLY NO
COMMAND_LINE_ARGUMENT OPTIONAL
VARIABLE_NAME INNODB_FATAL_SEMAPHORE_WAIT_THRESHOLD
SESSION_VALUE NULL
DEFAULT_VALUE 600
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BIGINT UNSIGNED
VARIABLE_COMMENT Maximum number of seconds that semaphore times out in InnoDB.
NUMERIC_MIN_VALUE 1
NUMERIC_MAX_VALUE 4294967295
NUMERIC_BLOCK_SIZE 0
ENUM_VALUE_LIST NULL
READ_ONLY YES
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_FILE_PER_TABLE
SESSION_VALUE NULL
DEFAULT_VALUE ON
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BOOLEAN
VARIABLE_COMMENT Stores each InnoDB table to an .ibd file in the database dir.
NUMERIC_MIN_VALUE NULL
NUMERIC_MAX_VALUE NULL
NUMERIC_BLOCK_SIZE NULL
ENUM_VALUE_LIST OFF,ON
READ_ONLY NO
COMMAND_LINE_ARGUMENT NONE
VARIABLE_NAME INNODB_FILL_FACTOR
SESSION_VALUE NULL
DEFAULT_VALUE 100
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE INT UNSIGNED
VARIABLE_COMMENT Percentage of B-tree page filled during bulk insert
NUMERIC_MIN_VALUE 10
NUMERIC_MAX_VALUE 100
NUMERIC_BLOCK_SIZE 0
ENUM_VALUE_LIST NULL
READ_ONLY NO
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_FIL_MAKE_PAGE_DIRTY_DEBUG
SESSION_VALUE NULL
DEFAULT_VALUE 0
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE INT UNSIGNED
VARIABLE_COMMENT Make the first page of the given tablespace dirty.
NUMERIC_MIN_VALUE 0
NUMERIC_MAX_VALUE 4294967295
NUMERIC_BLOCK_SIZE 0
ENUM_VALUE_LIST NULL
READ_ONLY NO
COMMAND_LINE_ARGUMENT OPTIONAL
VARIABLE_NAME INNODB_FLUSHING_AVG_LOOPS
SESSION_VALUE NULL
DEFAULT_VALUE 30
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BIGINT UNSIGNED
VARIABLE_COMMENT Number of iterations over which the background flushing is averaged.
NUMERIC_MIN_VALUE 1
NUMERIC_MAX_VALUE 1000
NUMERIC_BLOCK_SIZE 0
ENUM_VALUE_LIST NULL
READ_ONLY NO
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_FLUSH_LOG_AT_TIMEOUT
SESSION_VALUE NULL
DEFAULT_VALUE 1
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE INT UNSIGNED
VARIABLE_COMMENT Write and flush logs every (n) second.
NUMERIC_MIN_VALUE 0
NUMERIC_MAX_VALUE 2700
NUMERIC_BLOCK_SIZE 0
ENUM_VALUE_LIST NULL
READ_ONLY NO
COMMAND_LINE_ARGUMENT OPTIONAL
VARIABLE_NAME INNODB_FLUSH_LOG_AT_TRX_COMMIT
SESSION_VALUE NULL
DEFAULT_VALUE 1
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BIGINT UNSIGNED
VARIABLE_COMMENT Controls the durability/speed trade-off for commits. Set to 0 (write and flush redo log to disk only once per second), 1 (flush to disk at each commit), 2 (write to log at commit but flush to disk only once per second) or 3 (flush to disk at prepare and at commit, slower and usually redundant). 1 and 3 guarantees that after a crash, committed transactions will not be lost and will be consistent with the binlog and other transactional engines. 2 can get inconsistent and lose transactions if there is a power failure or kernel crash but not if mysqld crashes. 0 has no guarantees in case of crash. 0 and 2 can be faster than 1 or 3.
NUMERIC_MIN_VALUE 0
NUMERIC_MAX_VALUE 3
NUMERIC_BLOCK_SIZE 0
ENUM_VALUE_LIST NULL
READ_ONLY NO
COMMAND_LINE_ARGUMENT OPTIONAL
VARIABLE_NAME INNODB_FLUSH_METHOD
SESSION_VALUE NULL
DEFAULT_VALUE O_DIRECT
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE ENUM
VARIABLE_COMMENT With which method to flush data.
NUMERIC_MIN_VALUE NULL
NUMERIC_MAX_VALUE NULL
NUMERIC_BLOCK_SIZE NULL
ENUM_VALUE_LIST fsync,O_DSYNC,littlesync,nosync,O_DIRECT,O_DIRECT_NO_FSYNC
READ_ONLY YES
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_FLUSH_NEIGHBORS
SESSION_VALUE NULL
DEFAULT_VALUE 1
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BIGINT UNSIGNED
VARIABLE_COMMENT Set to 0 (don't flush neighbors from buffer pool), 1 (flush contiguous neighbors from buffer pool) or 2 (flush neighbors from buffer pool), when flushing a block
NUMERIC_MIN_VALUE 0
NUMERIC_MAX_VALUE 2
NUMERIC_BLOCK_SIZE 0
ENUM_VALUE_LIST NULL
READ_ONLY NO
COMMAND_LINE_ARGUMENT OPTIONAL
VARIABLE_NAME INNODB_FLUSH_SYNC
SESSION_VALUE NULL
DEFAULT_VALUE ON
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BOOLEAN
VARIABLE_COMMENT Allow IO bursts at the checkpoints ignoring io_capacity setting.
NUMERIC_MIN_VALUE NULL
NUMERIC_MAX_VALUE NULL
NUMERIC_BLOCK_SIZE NULL
ENUM_VALUE_LIST OFF,ON
READ_ONLY NO
COMMAND_LINE_ARGUMENT NONE
VARIABLE_NAME INNODB_FORCE_PRIMARY_KEY
SESSION_VALUE NULL
DEFAULT_VALUE OFF
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BOOLEAN
VARIABLE_COMMENT Do not allow creating a table without primary key (off by default)
NUMERIC_MIN_VALUE NULL
NUMERIC_MAX_VALUE NULL
NUMERIC_BLOCK_SIZE NULL
ENUM_VALUE_LIST OFF,ON
READ_ONLY NO
COMMAND_LINE_ARGUMENT OPTIONAL
VARIABLE_NAME INNODB_FORCE_RECOVERY
SESSION_VALUE NULL
DEFAULT_VALUE 0
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BIGINT UNSIGNED
VARIABLE_COMMENT Helps to save your data in case the disk image of the database becomes corrupt. Value 5 can return bogus data, and 6 can permanently corrupt data.
NUMERIC_MIN_VALUE 0
NUMERIC_MAX_VALUE 6
NUMERIC_BLOCK_SIZE 0
ENUM_VALUE_LIST NULL
READ_ONLY YES
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_FT_AUX_TABLE
SESSION_VALUE NULL
DEFAULT_VALUE
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE VARCHAR
VARIABLE_COMMENT FTS internal auxiliary table to be checked
NUMERIC_MIN_VALUE NULL
NUMERIC_MAX_VALUE NULL
NUMERIC_BLOCK_SIZE NULL
ENUM_VALUE_LIST NULL
READ_ONLY NO
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_FT_CACHE_SIZE
SESSION_VALUE NULL
DEFAULT_VALUE 8000000
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BIGINT UNSIGNED
VARIABLE_COMMENT InnoDB Fulltext search cache size in bytes
NUMERIC_MIN_VALUE 1600000
NUMERIC_MAX_VALUE 80000000
NUMERIC_BLOCK_SIZE 0
ENUM_VALUE_LIST NULL
READ_ONLY YES
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_FT_ENABLE_DIAG_PRINT
SESSION_VALUE NULL
DEFAULT_VALUE OFF
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BOOLEAN
VARIABLE_COMMENT Whether to enable additional FTS diagnostic printout
NUMERIC_MIN_VALUE NULL
NUMERIC_MAX_VALUE NULL
NUMERIC_BLOCK_SIZE NULL
ENUM_VALUE_LIST OFF,ON
READ_ONLY NO
COMMAND_LINE_ARGUMENT OPTIONAL
VARIABLE_NAME INNODB_FT_ENABLE_STOPWORD
SESSION_VALUE ON
DEFAULT_VALUE ON
VARIABLE_SCOPE SESSION
VARIABLE_TYPE BOOLEAN
VARIABLE_COMMENT Create FTS index with stopword.
NUMERIC_MIN_VALUE NULL
NUMERIC_MAX_VALUE NULL
NUMERIC_BLOCK_SIZE NULL
ENUM_VALUE_LIST OFF,ON
READ_ONLY NO
COMMAND_LINE_ARGUMENT OPTIONAL
VARIABLE_NAME INNODB_FT_MAX_TOKEN_SIZE
SESSION_VALUE NULL
DEFAULT_VALUE 84
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BIGINT UNSIGNED
VARIABLE_COMMENT InnoDB Fulltext search maximum token size in characters
NUMERIC_MIN_VALUE 10
NUMERIC_MAX_VALUE 84
NUMERIC_BLOCK_SIZE 0
ENUM_VALUE_LIST NULL
READ_ONLY YES
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_FT_MIN_TOKEN_SIZE
SESSION_VALUE NULL
DEFAULT_VALUE 3
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BIGINT UNSIGNED
VARIABLE_COMMENT InnoDB Fulltext search minimum token size in characters
NUMERIC_MIN_VALUE 0
NUMERIC_MAX_VALUE 16
NUMERIC_BLOCK_SIZE 0
ENUM_VALUE_LIST NULL
READ_ONLY YES
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_FT_NUM_WORD_OPTIMIZE
SESSION_VALUE NULL
DEFAULT_VALUE 2000
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BIGINT UNSIGNED
VARIABLE_COMMENT InnoDB Fulltext search number of words to optimize for each optimize table call
NUMERIC_MIN_VALUE 1000
NUMERIC_MAX_VALUE 10000
NUMERIC_BLOCK_SIZE 0
ENUM_VALUE_LIST NULL
READ_ONLY NO
COMMAND_LINE_ARGUMENT OPTIONAL
VARIABLE_NAME INNODB_FT_RESULT_CACHE_LIMIT
SESSION_VALUE NULL
DEFAULT_VALUE 2000000000
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BIGINT UNSIGNED
VARIABLE_COMMENT InnoDB Fulltext search query result cache limit in bytes
NUMERIC_MIN_VALUE 1000000
NUMERIC_MAX_VALUE 18446744073709551615
NUMERIC_BLOCK_SIZE 0
ENUM_VALUE_LIST NULL
READ_ONLY NO
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_FT_SERVER_STOPWORD_TABLE
SESSION_VALUE NULL
DEFAULT_VALUE
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE VARCHAR
VARIABLE_COMMENT The user supplied stopword table name.
NUMERIC_MIN_VALUE NULL
NUMERIC_MAX_VALUE NULL
NUMERIC_BLOCK_SIZE NULL
ENUM_VALUE_LIST NULL
READ_ONLY NO
COMMAND_LINE_ARGUMENT OPTIONAL
VARIABLE_NAME INNODB_FT_SORT_PLL_DEGREE
SESSION_VALUE NULL
DEFAULT_VALUE 2
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BIGINT UNSIGNED
VARIABLE_COMMENT InnoDB Fulltext search parallel sort degree, will round up to nearest power of 2 number
NUMERIC_MIN_VALUE 1
NUMERIC_MAX_VALUE 16
NUMERIC_BLOCK_SIZE 0
ENUM_VALUE_LIST NULL
READ_ONLY YES
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_FT_TOTAL_CACHE_SIZE
SESSION_VALUE NULL
DEFAULT_VALUE 640000000
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BIGINT UNSIGNED
VARIABLE_COMMENT Total memory allocated for InnoDB Fulltext Search cache
NUMERIC_MIN_VALUE 32000000
NUMERIC_MAX_VALUE 1600000000
NUMERIC_BLOCK_SIZE 0
ENUM_VALUE_LIST NULL
READ_ONLY YES
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_FT_USER_STOPWORD_TABLE
SESSION_VALUE
DEFAULT_VALUE
VARIABLE_SCOPE SESSION
VARIABLE_TYPE VARCHAR
VARIABLE_COMMENT User supplied stopword table name, effective in the session level.
NUMERIC_MIN_VALUE NULL
NUMERIC_MAX_VALUE NULL
NUMERIC_BLOCK_SIZE NULL
ENUM_VALUE_LIST NULL
READ_ONLY NO
COMMAND_LINE_ARGUMENT OPTIONAL
VARIABLE_NAME INNODB_IMMEDIATE_SCRUB_DATA_UNCOMPRESSED
SESSION_VALUE NULL
DEFAULT_VALUE OFF
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BOOLEAN
VARIABLE_COMMENT Enable scrubbing of data
NUMERIC_MIN_VALUE NULL
NUMERIC_MAX_VALUE NULL
NUMERIC_BLOCK_SIZE NULL
ENUM_VALUE_LIST OFF,ON
READ_ONLY NO
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_INSTANT_ALTER_COLUMN_ALLOWED
SESSION_VALUE NULL
DEFAULT_VALUE add_drop_reorder
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE ENUM
VARIABLE_COMMENT File format constraint for ALTER TABLE
NUMERIC_MIN_VALUE NULL
NUMERIC_MAX_VALUE NULL
NUMERIC_BLOCK_SIZE NULL
ENUM_VALUE_LIST never,add_last,add_drop_reorder
READ_ONLY NO
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_IO_CAPACITY
SESSION_VALUE NULL
DEFAULT_VALUE 200
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BIGINT UNSIGNED
VARIABLE_COMMENT Number of IOPs the server can do. Tunes the background IO rate
NUMERIC_MIN_VALUE 100
NUMERIC_MAX_VALUE 18446744073709551615
NUMERIC_BLOCK_SIZE 0
ENUM_VALUE_LIST NULL
READ_ONLY NO
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_IO_CAPACITY_MAX
SESSION_VALUE NULL
DEFAULT_VALUE 18446744073709551615
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BIGINT UNSIGNED
VARIABLE_COMMENT Limit to which innodb_io_capacity can be inflated.
NUMERIC_MIN_VALUE 100
NUMERIC_MAX_VALUE 18446744073709551615
NUMERIC_BLOCK_SIZE 0
ENUM_VALUE_LIST NULL
READ_ONLY NO
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_LIMIT_OPTIMISTIC_INSERT_DEBUG
SESSION_VALUE NULL
DEFAULT_VALUE 0
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE INT UNSIGNED
VARIABLE_COMMENT Artificially limit the number of records per B-tree page (0=unlimited).
NUMERIC_MIN_VALUE 0
NUMERIC_MAX_VALUE 4294967295
NUMERIC_BLOCK_SIZE 0
ENUM_VALUE_LIST NULL
READ_ONLY NO
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_LOCK_WAIT_TIMEOUT
SESSION_VALUE 50
DEFAULT_VALUE 50
VARIABLE_SCOPE SESSION
VARIABLE_TYPE INT UNSIGNED
VARIABLE_COMMENT Timeout in seconds an InnoDB transaction may wait for a lock before being rolled back. The value 100000000 is infinite timeout.
NUMERIC_MIN_VALUE 0
NUMERIC_MAX_VALUE 100000000
NUMERIC_BLOCK_SIZE 0
ENUM_VALUE_LIST NULL
READ_ONLY NO
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_LOG_BUFFER_SIZE
SESSION_VALUE NULL
DEFAULT_VALUE 16777216
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BIGINT UNSIGNED
VARIABLE_COMMENT Redo log buffer size in bytes.
NUMERIC_MIN_VALUE 2097152
NUMERIC_MAX_VALUE 18446744073709551615
NUMERIC_BLOCK_SIZE 4096
ENUM_VALUE_LIST NULL
READ_ONLY YES
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_LOG_CHECKPOINT_NOW
SESSION_VALUE NULL
DEFAULT_VALUE OFF
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BOOLEAN
VARIABLE_COMMENT Force checkpoint now
NUMERIC_MIN_VALUE NULL
NUMERIC_MAX_VALUE NULL
NUMERIC_BLOCK_SIZE NULL
ENUM_VALUE_LIST OFF,ON
READ_ONLY NO
COMMAND_LINE_ARGUMENT OPTIONAL
VARIABLE_NAME INNODB_LOG_FILE_SIZE
SESSION_VALUE NULL
DEFAULT_VALUE 100663296
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BIGINT UNSIGNED
VARIABLE_COMMENT Redo log size in bytes.
NUMERIC_MIN_VALUE 1048576
NUMERIC_MAX_VALUE 18446744073709551615
NUMERIC_BLOCK_SIZE 4096
ENUM_VALUE_LIST NULL
READ_ONLY YES
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_LOG_GROUP_HOME_DIR
SESSION_VALUE NULL
DEFAULT_VALUE
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE VARCHAR
VARIABLE_COMMENT Path to InnoDB log files.
NUMERIC_MIN_VALUE NULL
NUMERIC_MAX_VALUE NULL
NUMERIC_BLOCK_SIZE NULL
ENUM_VALUE_LIST NULL
READ_ONLY YES
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_LRU_FLUSH_SIZE
SESSION_VALUE NULL
DEFAULT_VALUE 32
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BIGINT UNSIGNED
VARIABLE_COMMENT How many pages to flush on LRU eviction
NUMERIC_MIN_VALUE 1
NUMERIC_MAX_VALUE 18446744073709551615
NUMERIC_BLOCK_SIZE 0
ENUM_VALUE_LIST NULL
READ_ONLY NO
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_LRU_SCAN_DEPTH
SESSION_VALUE NULL
DEFAULT_VALUE 1536
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BIGINT UNSIGNED
VARIABLE_COMMENT How deep to scan LRU to keep it clean
NUMERIC_MIN_VALUE 100
NUMERIC_MAX_VALUE 18446744073709551615
NUMERIC_BLOCK_SIZE 0
ENUM_VALUE_LIST NULL
READ_ONLY NO
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_MAX_DIRTY_PAGES_PCT
SESSION_VALUE NULL
DEFAULT_VALUE 90.000000
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE DOUBLE
VARIABLE_COMMENT Percentage of dirty pages allowed in bufferpool.
NUMERIC_MIN_VALUE 0
NUMERIC_MAX_VALUE 99.999
NUMERIC_BLOCK_SIZE NULL
ENUM_VALUE_LIST NULL
READ_ONLY NO
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_MAX_DIRTY_PAGES_PCT_LWM
SESSION_VALUE NULL
DEFAULT_VALUE 0.000000
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE DOUBLE
VARIABLE_COMMENT Percentage of dirty pages at which flushing kicks in. The value 0 (default) means 'refer to innodb_max_dirty_pages_pct'.
NUMERIC_MIN_VALUE 0
NUMERIC_MAX_VALUE 99.999
NUMERIC_BLOCK_SIZE NULL
ENUM_VALUE_LIST NULL
READ_ONLY NO
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_MAX_PURGE_LAG
SESSION_VALUE NULL
DEFAULT_VALUE 0
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BIGINT UNSIGNED
VARIABLE_COMMENT Desired maximum length of the purge queue (0 = no limit)
NUMERIC_MIN_VALUE 0
NUMERIC_MAX_VALUE 18446744073709551615
NUMERIC_BLOCK_SIZE 0
ENUM_VALUE_LIST NULL
READ_ONLY NO
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_MAX_PURGE_LAG_DELAY
SESSION_VALUE NULL
DEFAULT_VALUE 0
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BIGINT UNSIGNED
VARIABLE_COMMENT Maximum delay of user threads in micro-seconds
NUMERIC_MIN_VALUE 0
NUMERIC_MAX_VALUE 10000000
NUMERIC_BLOCK_SIZE 0
ENUM_VALUE_LIST NULL
READ_ONLY NO
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_MAX_PURGE_LAG_WAIT
SESSION_VALUE NULL
DEFAULT_VALUE 4294967295
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE INT UNSIGNED
VARIABLE_COMMENT Wait until History list length is below the specified limit
NUMERIC_MIN_VALUE 0
NUMERIC_MAX_VALUE 4294967295
NUMERIC_BLOCK_SIZE 0
ENUM_VALUE_LIST NULL
READ_ONLY NO
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_MAX_UNDO_LOG_SIZE
SESSION_VALUE NULL
DEFAULT_VALUE 10485760
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BIGINT UNSIGNED
VARIABLE_COMMENT Desired maximum UNDO tablespace size in bytes
NUMERIC_MIN_VALUE 10485760
NUMERIC_MAX_VALUE 281474976710656
NUMERIC_BLOCK_SIZE 0
ENUM_VALUE_LIST NULL
READ_ONLY NO
COMMAND_LINE_ARGUMENT OPTIONAL
VARIABLE_NAME INNODB_MERGE_THRESHOLD_SET_ALL_DEBUG
SESSION_VALUE NULL
DEFAULT_VALUE 50
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE INT UNSIGNED
VARIABLE_COMMENT Override current MERGE_THRESHOLD setting for all indexes at dictionary cache by the specified value dynamically, at the time.
NUMERIC_MIN_VALUE 1
NUMERIC_MAX_VALUE 50
NUMERIC_BLOCK_SIZE 0
ENUM_VALUE_LIST NULL
READ_ONLY NO
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_MONITOR_DISABLE
SESSION_VALUE NULL
DEFAULT_VALUE
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE VARCHAR
VARIABLE_COMMENT Turn off a monitor counter
NUMERIC_MIN_VALUE NULL
NUMERIC_MAX_VALUE NULL
NUMERIC_BLOCK_SIZE NULL
ENUM_VALUE_LIST NULL
READ_ONLY NO
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_MONITOR_ENABLE
SESSION_VALUE NULL
DEFAULT_VALUE
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE VARCHAR
VARIABLE_COMMENT Turn on a monitor counter
NUMERIC_MIN_VALUE NULL
NUMERIC_MAX_VALUE NULL
NUMERIC_BLOCK_SIZE NULL
ENUM_VALUE_LIST NULL
READ_ONLY NO
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_MONITOR_RESET
SESSION_VALUE NULL
DEFAULT_VALUE
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE VARCHAR
VARIABLE_COMMENT Reset a monitor counter
NUMERIC_MIN_VALUE NULL
NUMERIC_MAX_VALUE NULL
NUMERIC_BLOCK_SIZE NULL
ENUM_VALUE_LIST NULL
READ_ONLY NO
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_MONITOR_RESET_ALL
SESSION_VALUE NULL
DEFAULT_VALUE
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE VARCHAR
VARIABLE_COMMENT Reset all values for a monitor counter
NUMERIC_MIN_VALUE NULL
NUMERIC_MAX_VALUE NULL
NUMERIC_BLOCK_SIZE NULL
ENUM_VALUE_LIST NULL
READ_ONLY NO
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_OLD_BLOCKS_PCT
SESSION_VALUE NULL
DEFAULT_VALUE 37
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE INT UNSIGNED
VARIABLE_COMMENT Percentage of the buffer pool to reserve for 'old' blocks.
NUMERIC_MIN_VALUE 5
NUMERIC_MAX_VALUE 95
NUMERIC_BLOCK_SIZE 0
ENUM_VALUE_LIST NULL
READ_ONLY NO
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_OLD_BLOCKS_TIME
SESSION_VALUE NULL
DEFAULT_VALUE 1000
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE INT UNSIGNED
VARIABLE_COMMENT Move blocks to the 'new' end of the buffer pool if the first access was at least this many milliseconds ago. The timeout is disabled if 0.
NUMERIC_MIN_VALUE 0
NUMERIC_MAX_VALUE 4294967295
NUMERIC_BLOCK_SIZE 0
ENUM_VALUE_LIST NULL
READ_ONLY NO
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_ONLINE_ALTER_LOG_MAX_SIZE
SESSION_VALUE NULL
DEFAULT_VALUE 134217728
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BIGINT UNSIGNED
VARIABLE_COMMENT Maximum modification log file size for online index creation
NUMERIC_MIN_VALUE 65536
NUMERIC_MAX_VALUE 18446744073709551615
NUMERIC_BLOCK_SIZE 0
ENUM_VALUE_LIST NULL
READ_ONLY NO
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_OPEN_FILES
SESSION_VALUE NULL
DEFAULT_VALUE 0
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BIGINT UNSIGNED
VARIABLE_COMMENT How many files at the maximum InnoDB keeps open at the same time.
NUMERIC_MIN_VALUE 0
NUMERIC_MAX_VALUE 9223372036854775807
NUMERIC_BLOCK_SIZE 0
ENUM_VALUE_LIST NULL
READ_ONLY YES
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_OPTIMIZE_FULLTEXT_ONLY
SESSION_VALUE NULL
DEFAULT_VALUE OFF
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BOOLEAN
VARIABLE_COMMENT Only optimize the Fulltext index of the table
NUMERIC_MIN_VALUE NULL
NUMERIC_MAX_VALUE NULL
NUMERIC_BLOCK_SIZE NULL
ENUM_VALUE_LIST OFF,ON
READ_ONLY NO
COMMAND_LINE_ARGUMENT NONE
VARIABLE_NAME INNODB_PAGE_SIZE
SESSION_VALUE NULL
DEFAULT_VALUE 16384
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BIGINT UNSIGNED
VARIABLE_COMMENT Page size to use for all InnoDB tablespaces.
NUMERIC_MIN_VALUE 4096
NUMERIC_MAX_VALUE 65536
NUMERIC_BLOCK_SIZE 0
ENUM_VALUE_LIST NULL
READ_ONLY YES
COMMAND_LINE_ARGUMENT OPTIONAL
VARIABLE_NAME INNODB_PREFIX_INDEX_CLUSTER_OPTIMIZATION
SESSION_VALUE NULL
DEFAULT_VALUE OFF
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BOOLEAN
VARIABLE_COMMENT Enable prefix optimization to sometimes avoid cluster index lookups.
NUMERIC_MIN_VALUE NULL
NUMERIC_MAX_VALUE NULL
NUMERIC_BLOCK_SIZE NULL
ENUM_VALUE_LIST OFF,ON
READ_ONLY NO
COMMAND_LINE_ARGUMENT OPTIONAL
VARIABLE_NAME INNODB_PRINT_ALL_DEADLOCKS
SESSION_VALUE NULL
DEFAULT_VALUE OFF
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BOOLEAN
VARIABLE_COMMENT Print all deadlocks to MariaDB error log (off by default)
NUMERIC_MIN_VALUE NULL
NUMERIC_MAX_VALUE NULL
NUMERIC_BLOCK_SIZE NULL
ENUM_VALUE_LIST OFF,ON
READ_ONLY NO
COMMAND_LINE_ARGUMENT OPTIONAL
VARIABLE_NAME INNODB_PURGE_BATCH_SIZE
SESSION_VALUE NULL
DEFAULT_VALUE 300
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BIGINT UNSIGNED
VARIABLE_COMMENT Number of UNDO log pages to purge in one batch from the history list.
NUMERIC_MIN_VALUE 1
NUMERIC_MAX_VALUE 5000
NUMERIC_BLOCK_SIZE 0
ENUM_VALUE_LIST NULL
READ_ONLY NO
COMMAND_LINE_ARGUMENT OPTIONAL
VARIABLE_NAME INNODB_PURGE_RSEG_TRUNCATE_FREQUENCY
SESSION_VALUE NULL
DEFAULT_VALUE 128
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BIGINT UNSIGNED
VARIABLE_COMMENT Dictates rate at which UNDO records are purged. Value N means purge rollback segment(s) on every Nth iteration of purge invocation
NUMERIC_MIN_VALUE 1
NUMERIC_MAX_VALUE 128
NUMERIC_BLOCK_SIZE 0
ENUM_VALUE_LIST NULL
READ_ONLY NO
COMMAND_LINE_ARGUMENT OPTIONAL
VARIABLE_NAME INNODB_PURGE_THREADS
SESSION_VALUE NULL
DEFAULT_VALUE 4
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE INT UNSIGNED
VARIABLE_COMMENT Number of tasks for purging transaction history
NUMERIC_MIN_VALUE 1
NUMERIC_MAX_VALUE 32
NUMERIC_BLOCK_SIZE 0
ENUM_VALUE_LIST NULL
READ_ONLY NO
COMMAND_LINE_ARGUMENT OPTIONAL
VARIABLE_NAME INNODB_RANDOM_READ_AHEAD
SESSION_VALUE NULL
DEFAULT_VALUE OFF
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BOOLEAN
VARIABLE_COMMENT Whether to use read ahead for random access within an extent.
NUMERIC_MIN_VALUE NULL
NUMERIC_MAX_VALUE NULL
NUMERIC_BLOCK_SIZE NULL
ENUM_VALUE_LIST OFF,ON
READ_ONLY NO
COMMAND_LINE_ARGUMENT NONE
VARIABLE_NAME INNODB_READ_AHEAD_THRESHOLD
SESSION_VALUE NULL
DEFAULT_VALUE 56
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BIGINT UNSIGNED
VARIABLE_COMMENT Number of pages that must be accessed sequentially for InnoDB to trigger a readahead.
NUMERIC_MIN_VALUE 0
NUMERIC_MAX_VALUE 64
NUMERIC_BLOCK_SIZE 0
ENUM_VALUE_LIST NULL
READ_ONLY NO
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_READ_IO_THREADS
SESSION_VALUE NULL
DEFAULT_VALUE 4
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE INT UNSIGNED
VARIABLE_COMMENT Number of background read I/O threads in InnoDB.
NUMERIC_MIN_VALUE 1
NUMERIC_MAX_VALUE 64
NUMERIC_BLOCK_SIZE 0
ENUM_VALUE_LIST NULL
READ_ONLY YES
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_READ_ONLY
SESSION_VALUE NULL
DEFAULT_VALUE OFF
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BOOLEAN
VARIABLE_COMMENT Start InnoDB in read only mode (off by default)
NUMERIC_MIN_VALUE NULL
NUMERIC_MAX_VALUE NULL
NUMERIC_BLOCK_SIZE NULL
ENUM_VALUE_LIST OFF,ON
READ_ONLY YES
COMMAND_LINE_ARGUMENT OPTIONAL
VARIABLE_NAME INNODB_READ_ONLY_COMPRESSED
SESSION_VALUE NULL
DEFAULT_VALUE ON
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BOOLEAN
VARIABLE_COMMENT Make ROW_FORMAT=COMPRESSED tables read-only (ON by default)
NUMERIC_MIN_VALUE NULL
NUMERIC_MAX_VALUE NULL
NUMERIC_BLOCK_SIZE NULL
ENUM_VALUE_LIST OFF,ON
READ_ONLY NO
COMMAND_LINE_ARGUMENT OPTIONAL
VARIABLE_NAME INNODB_ROLLBACK_ON_TIMEOUT
SESSION_VALUE NULL
DEFAULT_VALUE OFF
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BOOLEAN
VARIABLE_COMMENT Roll back the complete transaction on lock wait timeout, for 4.x compatibility (disabled by default)
NUMERIC_MIN_VALUE NULL
NUMERIC_MAX_VALUE NULL
NUMERIC_BLOCK_SIZE NULL
ENUM_VALUE_LIST OFF,ON
READ_ONLY YES
COMMAND_LINE_ARGUMENT OPTIONAL
VARIABLE_NAME INNODB_SAVED_PAGE_NUMBER_DEBUG
SESSION_VALUE NULL
DEFAULT_VALUE 0
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE INT UNSIGNED
VARIABLE_COMMENT An InnoDB page number.
NUMERIC_MIN_VALUE 0
NUMERIC_MAX_VALUE 4294967295
NUMERIC_BLOCK_SIZE 0
ENUM_VALUE_LIST NULL
READ_ONLY NO
COMMAND_LINE_ARGUMENT OPTIONAL
VARIABLE_NAME INNODB_SORT_BUFFER_SIZE
SESSION_VALUE NULL
DEFAULT_VALUE 1048576
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BIGINT UNSIGNED
VARIABLE_COMMENT Memory buffer size for index creation
NUMERIC_MIN_VALUE 65536
NUMERIC_MAX_VALUE 67108864
NUMERIC_BLOCK_SIZE 0
ENUM_VALUE_LIST NULL
READ_ONLY YES
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_SPIN_WAIT_DELAY
SESSION_VALUE NULL
DEFAULT_VALUE 4
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE INT UNSIGNED
VARIABLE_COMMENT Maximum delay between polling for a spin lock (4 by default)
NUMERIC_MIN_VALUE 0
NUMERIC_MAX_VALUE 6000
NUMERIC_BLOCK_SIZE 0
ENUM_VALUE_LIST NULL
READ_ONLY NO
COMMAND_LINE_ARGUMENT OPTIONAL
VARIABLE_NAME INNODB_STATS_AUTO_RECALC
SESSION_VALUE NULL
DEFAULT_VALUE ON
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BOOLEAN
VARIABLE_COMMENT InnoDB automatic recalculation of persistent statistics enabled for all tables unless overridden at table level (automatic recalculation is only done when InnoDB decides that the table has changed too much and needs a new statistics)
NUMERIC_MIN_VALUE NULL
NUMERIC_MAX_VALUE NULL
NUMERIC_BLOCK_SIZE NULL
ENUM_VALUE_LIST OFF,ON
READ_ONLY NO
COMMAND_LINE_ARGUMENT OPTIONAL
VARIABLE_NAME INNODB_STATS_INCLUDE_DELETE_MARKED
SESSION_VALUE NULL
DEFAULT_VALUE OFF
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BOOLEAN
VARIABLE_COMMENT Include delete marked records when calculating persistent statistics
NUMERIC_MIN_VALUE NULL
NUMERIC_MAX_VALUE NULL
NUMERIC_BLOCK_SIZE NULL
ENUM_VALUE_LIST OFF,ON
READ_ONLY NO
COMMAND_LINE_ARGUMENT OPTIONAL
VARIABLE_NAME INNODB_STATS_METHOD
SESSION_VALUE NULL
DEFAULT_VALUE nulls_equal
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE ENUM
VARIABLE_COMMENT Specifies how InnoDB index statistics collection code should treat NULLs. Possible values are NULLS_EQUAL (default), NULLS_UNEQUAL and NULLS_IGNORED
NUMERIC_MIN_VALUE NULL
NUMERIC_MAX_VALUE NULL
NUMERIC_BLOCK_SIZE NULL
ENUM_VALUE_LIST nulls_equal,nulls_unequal,nulls_ignored
READ_ONLY NO
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_STATS_MODIFIED_COUNTER
SESSION_VALUE NULL
DEFAULT_VALUE 0
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BIGINT UNSIGNED
VARIABLE_COMMENT The number of rows modified before we calculate new statistics (default 0 = current limits)
NUMERIC_MIN_VALUE 0
NUMERIC_MAX_VALUE 18446744073709551615
NUMERIC_BLOCK_SIZE 0
ENUM_VALUE_LIST NULL
READ_ONLY NO
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_STATS_ON_METADATA
SESSION_VALUE NULL
DEFAULT_VALUE OFF
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BOOLEAN
VARIABLE_COMMENT Enable statistics gathering for metadata commands such as SHOW TABLE STATUS for tables that use transient statistics (off by default)
NUMERIC_MIN_VALUE NULL
NUMERIC_MAX_VALUE NULL
NUMERIC_BLOCK_SIZE NULL
ENUM_VALUE_LIST OFF,ON
READ_ONLY NO
COMMAND_LINE_ARGUMENT OPTIONAL
VARIABLE_NAME INNODB_STATS_PERSISTENT
SESSION_VALUE NULL
DEFAULT_VALUE ON
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BOOLEAN
VARIABLE_COMMENT InnoDB persistent statistics enabled for all tables unless overridden at table level
NUMERIC_MIN_VALUE NULL
NUMERIC_MAX_VALUE NULL
NUMERIC_BLOCK_SIZE NULL
ENUM_VALUE_LIST OFF,ON
READ_ONLY NO
COMMAND_LINE_ARGUMENT OPTIONAL
VARIABLE_NAME INNODB_STATS_PERSISTENT_SAMPLE_PAGES
SESSION_VALUE NULL
DEFAULT_VALUE 20
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BIGINT UNSIGNED
VARIABLE_COMMENT The number of leaf index pages to sample when calculating persistent statistics (by ANALYZE, default 20)
NUMERIC_MIN_VALUE 1
NUMERIC_MAX_VALUE 18446744073709551615
NUMERIC_BLOCK_SIZE 0
ENUM_VALUE_LIST NULL
READ_ONLY NO
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_STATS_TRADITIONAL
SESSION_VALUE NULL
DEFAULT_VALUE ON
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BOOLEAN
VARIABLE_COMMENT Enable traditional statistic calculation based on number of configured pages (default true)
NUMERIC_MIN_VALUE NULL
NUMERIC_MAX_VALUE NULL
NUMERIC_BLOCK_SIZE NULL
ENUM_VALUE_LIST OFF,ON
READ_ONLY NO
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_STATS_TRANSIENT_SAMPLE_PAGES
SESSION_VALUE NULL
DEFAULT_VALUE 8
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BIGINT UNSIGNED
VARIABLE_COMMENT The number of leaf index pages to sample when calculating transient statistics (if persistent statistics are not used, default 8)
NUMERIC_MIN_VALUE 1
NUMERIC_MAX_VALUE 18446744073709551615
NUMERIC_BLOCK_SIZE 0
ENUM_VALUE_LIST NULL
READ_ONLY NO
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_STATUS_OUTPUT
SESSION_VALUE NULL
DEFAULT_VALUE OFF
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BOOLEAN
VARIABLE_COMMENT Enable InnoDB monitor output to the error log.
NUMERIC_MIN_VALUE NULL
NUMERIC_MAX_VALUE NULL
NUMERIC_BLOCK_SIZE NULL
ENUM_VALUE_LIST OFF,ON
READ_ONLY NO
COMMAND_LINE_ARGUMENT OPTIONAL
VARIABLE_NAME INNODB_STATUS_OUTPUT_LOCKS
SESSION_VALUE NULL
DEFAULT_VALUE OFF
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BOOLEAN
VARIABLE_COMMENT Enable InnoDB lock monitor output to the error log. Requires innodb_status_output=ON.
NUMERIC_MIN_VALUE NULL
NUMERIC_MAX_VALUE NULL
NUMERIC_BLOCK_SIZE NULL
ENUM_VALUE_LIST OFF,ON
READ_ONLY NO
COMMAND_LINE_ARGUMENT OPTIONAL
VARIABLE_NAME INNODB_STRICT_MODE
SESSION_VALUE ON
DEFAULT_VALUE ON
VARIABLE_SCOPE SESSION
VARIABLE_TYPE BOOLEAN
VARIABLE_COMMENT Use strict mode when evaluating create options.
NUMERIC_MIN_VALUE NULL
NUMERIC_MAX_VALUE NULL
NUMERIC_BLOCK_SIZE NULL
ENUM_VALUE_LIST OFF,ON
READ_ONLY NO
COMMAND_LINE_ARGUMENT OPTIONAL
VARIABLE_NAME INNODB_SYNC_SPIN_LOOPS
SESSION_VALUE NULL
DEFAULT_VALUE 30
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BIGINT UNSIGNED
VARIABLE_COMMENT Count of spin-loop rounds in InnoDB mutexes (30 by default)
NUMERIC_MIN_VALUE 0
NUMERIC_MAX_VALUE 18446744073709551615
NUMERIC_BLOCK_SIZE 0
ENUM_VALUE_LIST NULL
READ_ONLY NO
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_TABLE_LOCKS
SESSION_VALUE ON
DEFAULT_VALUE ON
VARIABLE_SCOPE SESSION
VARIABLE_TYPE BOOLEAN
VARIABLE_COMMENT Enable InnoDB locking in LOCK TABLES
NUMERIC_MIN_VALUE NULL
NUMERIC_MAX_VALUE NULL
NUMERIC_BLOCK_SIZE NULL
ENUM_VALUE_LIST OFF,ON
READ_ONLY NO
COMMAND_LINE_ARGUMENT OPTIONAL
VARIABLE_NAME INNODB_TEMP_DATA_FILE_PATH
SESSION_VALUE NULL
DEFAULT_VALUE ibtmp1:12M:autoextend
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE VARCHAR
VARIABLE_COMMENT Path to files and their sizes making temp-tablespace.
NUMERIC_MIN_VALUE NULL
NUMERIC_MAX_VALUE NULL
NUMERIC_BLOCK_SIZE NULL
ENUM_VALUE_LIST NULL
READ_ONLY YES
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_TMPDIR
SESSION_VALUE
DEFAULT_VALUE
VARIABLE_SCOPE SESSION
VARIABLE_TYPE VARCHAR
VARIABLE_COMMENT Directory for temporary non-tablespace files.
NUMERIC_MIN_VALUE NULL
NUMERIC_MAX_VALUE NULL
NUMERIC_BLOCK_SIZE NULL
ENUM_VALUE_LIST NULL
READ_ONLY NO
COMMAND_LINE_ARGUMENT OPTIONAL
VARIABLE_NAME INNODB_TRX_PURGE_VIEW_UPDATE_ONLY_DEBUG
SESSION_VALUE NULL
DEFAULT_VALUE OFF
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BOOLEAN
VARIABLE_COMMENT Pause actual purging any delete-marked records, but merely update the purge view. It is to create artificially the situation the purge view have been updated but the each purges were not done yet.
NUMERIC_MIN_VALUE NULL
NUMERIC_MAX_VALUE NULL
NUMERIC_BLOCK_SIZE NULL
ENUM_VALUE_LIST OFF,ON
READ_ONLY NO
COMMAND_LINE_ARGUMENT NULL
VARIABLE_NAME INNODB_TRX_RSEG_N_SLOTS_DEBUG
SESSION_VALUE NULL
DEFAULT_VALUE 0
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE INT UNSIGNED
VARIABLE_COMMENT Debug flags for InnoDB to limit TRX_RSEG_N_SLOTS for trx_rsegf_undo_find_free()
NUMERIC_MIN_VALUE 0
NUMERIC_MAX_VALUE 1024
NUMERIC_BLOCK_SIZE 0
ENUM_VALUE_LIST NULL
READ_ONLY NO
COMMAND_LINE_ARGUMENT NULL
VARIABLE_NAME INNODB_UNDO_DIRECTORY
SESSION_VALUE NULL
DEFAULT_VALUE
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE VARCHAR
VARIABLE_COMMENT Directory where undo tablespace files live, this path can be absolute.
NUMERIC_MIN_VALUE NULL
NUMERIC_MAX_VALUE NULL
NUMERIC_BLOCK_SIZE NULL
ENUM_VALUE_LIST NULL
READ_ONLY YES
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_UNDO_LOG_TRUNCATE
SESSION_VALUE NULL
DEFAULT_VALUE OFF
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BOOLEAN
VARIABLE_COMMENT Enable or Disable Truncate of UNDO tablespace.
NUMERIC_MIN_VALUE NULL
NUMERIC_MAX_VALUE NULL
NUMERIC_BLOCK_SIZE NULL
ENUM_VALUE_LIST OFF,ON
READ_ONLY NO
COMMAND_LINE_ARGUMENT OPTIONAL
VARIABLE_NAME INNODB_UNDO_TABLESPACES
SESSION_VALUE NULL
DEFAULT_VALUE 0
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE INT UNSIGNED
VARIABLE_COMMENT Number of undo tablespaces to use.
NUMERIC_MIN_VALUE 0
NUMERIC_MAX_VALUE 127
NUMERIC_BLOCK_SIZE 0
ENUM_VALUE_LIST NULL
READ_ONLY YES
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME INNODB_USE_ATOMIC_WRITES
SESSION_VALUE NULL
DEFAULT_VALUE ON
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BOOLEAN
VARIABLE_COMMENT Enable atomic writes, instead of using the doublewrite buffer, for files on devices that supports atomic writes.
NUMERIC_MIN_VALUE NULL
NUMERIC_MAX_VALUE NULL
NUMERIC_BLOCK_SIZE NULL
ENUM_VALUE_LIST OFF,ON
READ_ONLY YES
COMMAND_LINE_ARGUMENT NONE
VARIABLE_NAME INNODB_WRITE_IO_THREADS
SESSION_VALUE NULL
DEFAULT_VALUE 4
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE INT UNSIGNED
VARIABLE_COMMENT Number of background write I/O threads in InnoDB.
NUMERIC_MIN_VALUE 2
NUMERIC_MAX_VALUE 64
NUMERIC_BLOCK_SIZE 0
ENUM_VALUE_LIST NULL
READ_ONLY YES
COMMAND_LINE_ARGUMENT REQUIRED
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