Storage engines

InnoDB

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

[ Variables | Buffer Pool | InnoDB Status ]

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2026-07-30 17:25:45 0x7fd7a815a640 INNODB MONITOR OUTPUT
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Per second averages calculated from the last 52 seconds
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BACKGROUND THREAD
-----------------
srv_master_thread loops: 1292 srv_active, 0 srv_shutdown, 157365 srv_idle
srv_master_thread log flush and writes: 158602
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SEMAPHORES
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OS WAIT ARRAY INFO: reservation count 24780
OS WAIT ARRAY INFO: signal count 20332
RW-shared spins 13009, rounds 98970, OS waits 1546
RW-excl spins 12364, rounds 151923, OS waits 2980
RW-sx spins 134, rounds 3083, OS waits 87
Spin rounds per wait: 7.61 RW-shared, 12.29 RW-excl, 23.01 RW-sx
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LATEST FOREIGN KEY ERROR
------------------------
2026-07-28 23:04:36 0x7fd7ac9b4640  Cannot drop table `cu_theses`.`theses`
because it is referenced by `cu_theses`.`researchers`
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TRANSACTIONS
------------
Trx id counter 130935
Purge done for trx's n:o < 130935 undo n:o < 0 state: running but idle
History list length 0
LIST OF TRANSACTIONS FOR EACH SESSION:
---TRANSACTION 422039217803528, not started
0 lock struct(s), heap size 1128, 0 row lock(s)
---TRANSACTION 422039217799312, not started
0 lock struct(s), heap size 1128, 0 row lock(s)
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FILE I/O
--------
I/O thread 0 state: waiting for i/o request (insert buffer thread)
I/O thread 1 state: waiting for i/o request (log thread)
I/O thread 2 state: waiting for i/o request (read thread)
I/O thread 3 state: waiting for i/o request (read thread)
I/O thread 4 state: waiting for i/o request (read thread)
I/O thread 5 state: waiting for i/o request (read thread)
I/O thread 6 state: waiting for i/o request (write thread)
I/O thread 7 state: waiting for i/o request (write thread)
I/O thread 8 state: waiting for i/o request (write thread)
I/O thread 9 state: waiting for i/o request (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
229285 OS file reads, 137822 OS file writes, 52304 OS fsyncs
11.65 reads/s, 16384 avg bytes/read, 12.77 writes/s, 5.46 fsyncs/s
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INSERT BUFFER AND ADAPTIVE HASH INDEX
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Ibuf: size 1, free list len 17, seg size 19, 347 merges
merged operations:
 insert 4914, delete mark 1, delete 0
discarded operations:
 insert 0, delete mark 0, delete 0
Hash table size 4441, node heap has 0 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)
23.04 hash searches/s, 47.10 non-hash searches/s
---
LOG
---
Log sequence number 687556211
Log flushed up to   687555568
Pages flushed up to 687511484
Last checkpoint at  687508673
0 pending log flushes, 0 pending chkp writes
8869 log i/o's done, 4.13 log i/o's/second
----------------------
BUFFER POOL AND MEMORY
----------------------
Total large memory allocated 33554432
Dictionary memory allocated 671000
Buffer pool size   1002
Free buffers       735
Database pages     260
Old database pages 0
Modified db pages  82
Percent of dirty pages(LRU & free pages): 8.233
Max dirty pages percent: 75.000
Pending reads 0
Pending writes: LRU 0, flush list 0, single page 0
Pages made young 3728, not young 6352257
0.00 youngs/s, 0.00 non-youngs/s
Pages read 228838, created 11870, written 107701
11.65 reads/s, 0.17 creates/s, 8.02 writes/s
Buffer pool hit rate 957 / 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: 260, unzip_LRU len: 0
I/O sum[978]:cur[10], unzip sum[0]:cur[0]
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ROW OPERATIONS
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0 queries inside InnoDB, 0 queries in queue
0 read views open inside InnoDB
Process ID=106707, Main thread ID=140563777041984, state: sleeping
Number of rows inserted 55369, updated 4916, deleted 580, read 9273981
0.00 inserts/s, 3.46 updates/s, 0.00 deletes/s, 608.01 reads/s
Number of system rows inserted 0, updated 0, deleted 0, read 75002
0.00 inserts/s, 0.00 updates/s, 0.00 deletes/s, 0.00 reads/s
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END OF INNODB MONITOR OUTPUT
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