Storage engines

InnoDB

Supports transactions, row-level locking, foreign keys and encryption for tables

[ Variables | Buffer Pool | InnoDB Status ]

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2026-08-14 22:03:18 0xd00 INNODB MONITOR OUTPUT
=====================================
Per second averages calculated from the last 39 seconds
-----------------
BACKGROUND THREAD
-----------------
srv_master_thread loops: 9128 srv_active, 0 srv_shutdown, 7855 srv_idle
srv_master_thread log flush and writes: 16983
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SEMAPHORES
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OS WAIT ARRAY INFO: reservation count 75342
OS WAIT ARRAY INFO: signal count 15169
RW-shared spins 3563, rounds 96560, OS waits 3058
RW-excl spins 771, rounds 10172, OS waits 269
RW-sx spins 3, rounds 90, OS waits 2
Spin rounds per wait: 27.10 RW-shared, 13.19 RW-excl, 30.00 RW-sx
------------------------
LATEST FOREIGN KEY ERROR
------------------------
2026-08-14 17:40:13 0xfd8 Error in foreign key constraint creation for table `restobar_db`.`#sql-12c0_36`.
A foreign key constraint of name `restobar_db`.`fk_orders_client`
already exists. (Note that internally InnoDB adds 'databasename'
in front of the user-defined constraint name.)
Note that InnoDB's FOREIGN KEY system tables store
constraint names as case-insensitive, with the
MySQL standard latin1_swedish_ci collation. If you
create tables or databases whose names differ only in
the character case, then collisions in constraint
names can occur. Workaround: name your constraints
explicitly with unique names.
------------
TRANSACTIONS
------------
Trx id counter 688435
Purge done for trx's n:o < 688435 undo n:o < 0 state: running
History list length 6
LIST OF TRANSACTIONS FOR EACH SESSION:
---TRANSACTION 284279215767768, not started
0 lock struct(s), heap size 1128, 0 row lock(s)
---TRANSACTION 284279215776104, not started
0 lock struct(s), heap size 1128, 0 row lock(s)
---TRANSACTION 284279215763600, not started
0 lock struct(s), heap size 1128, 0 row lock(s)
---TRANSACTION 284279215771936, not started
0 lock struct(s), heap size 1128, 0 row lock(s)
--------
FILE I/O
--------
I/O thread 0 state: native aio handle (insert buffer thread)
I/O thread 1 state: native aio handle (log thread)
I/O thread 2 state: native aio handle (read thread)
I/O thread 3 state: native aio handle (read thread)
I/O thread 4 state: native aio handle (read thread)
I/O thread 5 state: native aio handle (read thread)
I/O thread 6 state: native aio handle (write thread)
I/O thread 7 state: native aio handle (write thread)
I/O thread 8 state: native aio handle (write thread)
I/O thread 9 state: native aio handle (write thread)
Pending normal aio reads: [0, 0, 0, 0] , aio writes: [0, 0, 0, 0] ,
 ibuf aio reads:, log i/o's:, sync i/o's:
Pending flushes (fsync) log: 0; buffer pool: 0
170461 OS file reads, 116549 OS file writes, 64895 OS fsyncs
34.33 reads/s, 16384 avg bytes/read, 17.79 writes/s, 9.23 fsyncs/s
-------------------------------------
INSERT BUFFER AND ADAPTIVE HASH INDEX
-------------------------------------
Ibuf: size 1, free list len 0, seg size 2, 1401 merges
merged operations:
 insert 1254, delete mark 149, delete 0
discarded operations:
 insert 0, delete mark 0, delete 0
Hash table size 4441, node heap has 1 buffer(s)
Hash table size 4441, node heap has 1 buffer(s)
Hash table size 4441, node heap has 1 buffer(s)
Hash table size 4441, node heap has 1 buffer(s)
Hash table size 4441, node heap has 1 buffer(s)
Hash table size 4441, node heap has 1 buffer(s)
Hash table size 4441, node heap has 1 buffer(s)
Hash table size 4441, node heap has 1 buffer(s)
89.48 hash searches/s, 195.53 non-hash searches/s
---
LOG
---
Log sequence number 160478670
Log flushed up to   160478650
Pages flushed up to 160417725
Last checkpoint at  160410087
0 pending log flushes, 0 pending chkp writes
30921 log i/o's done, 6.36 log i/o's/second
----------------------
BUFFER POOL AND MEMORY
----------------------
Total large memory allocated 33554432
Dictionary memory allocated 150240
Buffer pool size   1003
Free buffers       737
Database pages     258
Old database pages 0
Modified db pages  116
Percent of dirty pages(LRU & free pages): 11.647
Max dirty pages percent: 75.000
Pending reads 0
Pending writes: LRU 0, flush list 0, single page 0
Pages made young 1116, not young 137618
0.00 youngs/s, 0.00 non-youngs/s
Pages read 170400, created 760, written 73915
36.03 reads/s, 0.25 creates/s, 11.62 writes/s
Buffer pool hit rate 963 / 1000, young-making rate 0 / 1000 not 0 / 1000
Pages read ahead 0.00/s, evicted without access 0.00/s, Random read ahead 0.00/s
LRU len: 258, unzip_LRU len: 0
I/O sum[2430]:cur[6], unzip sum[0]:cur[0]
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ROW OPERATIONS
--------------
0 queries inside InnoDB, 0 queries in queue
0 read views open inside InnoDB
Process ID=4216, Main thread ID=5344, state: sleeping
Number of rows inserted 1368, updated 15189, deleted 36, read 14272576
0.00 inserts/s, 5.08 updates/s, 0.00 deletes/s, 562.17 reads/s
Number of system rows inserted 0, updated 0, deleted 0, read 25598
0.00 inserts/s, 0.00 updates/s, 0.00 deletes/s, 0.00 reads/s
----------------------------
END OF INNODB MONITOR OUTPUT
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