Storage engines

InnoDB

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

[ Variables | Buffer Pool | InnoDB Status ]

=====================================
2025-07-09 03:17:37 0x23f4 INNODB MONITOR OUTPUT
=====================================
Per second averages calculated from the last 6 seconds
-----------------
BACKGROUND THREAD
-----------------
srv_master_thread loops: 212376 srv_active, 0 srv_shutdown, 3761957 srv_idle
srv_master_thread log flush and writes: 3974333
----------
SEMAPHORES
----------
OS WAIT ARRAY INFO: reservation count 12745661
OS WAIT ARRAY INFO: signal count 9127282
RW-shared spins 9019770, rounds 239705562, OS waits 7286935
RW-excl spins 5719514, rounds 11238446, OS waits 142962
RW-sx spins 119524, rounds 1311107, OS waits 25485
Spin rounds per wait: 26.58 RW-shared, 1.96 RW-excl, 10.97 RW-sx
------------------------
LATEST FOREIGN KEY ERROR
------------------------
2025-07-08 15:24:01 0x1a60 Transaction:
TRANSACTION 30576741, ACTIVE 0 sec updating or deleting
mysql tables in use 2, locked 2
4 lock struct(s), heap size 1128, 2 row lock(s), undo log entries 1
MySQL thread id 2094952, OS thread handle 6752, query id 41501551 localhost 127.0.0.1 root Updating
DELETE FROM `users` WHERE `users`.`id` = 4
Foreign key constraint fails for table `freelumaartists`.`concept_images`:
,
  CONSTRAINT `concept_images_ibfk_2` FOREIGN KEY (`uploaded_by`) REFERENCES `users` (`id`)
Trying to delete or update in parent table, in index PRIMARY tuple:
DATA TUPLE: 12 fields;
 0: len 4; hex 80000004; asc     ;;
 1: len 6; hex 000001d29065; asc      e;;
 2: len 7; hex 40000001dc08c6; asc @      ;;
 3: len 16; hex 4b616d62726961205363686166666572; asc Kambria Schaffer;;
 4: len 17; hex 6b786d6272696140676d61696c2e636f6d; asc kxmbria@gmail.com;;
 5: len 0; hex ; asc ;;
 6: len 1; hex 01; asc  ;;
 7: len 1; hex 81; asc  ;;
 8: len 1; hex 80; asc  ;;
 9: len 5; hex 99b6f4d10a; asc      ;;
 10: len 60; hex 24327924313024736269766e6d6a52645533554a4d65644834636c6b4f2f764355474d45553571303853764a743677636869504b4d784678654b4d61; asc $2y$10$sbivnmjRdU3UJMedH4clkO/vCUGMEU5q08SvJt6wchiPKMxFxeKMa;;
 11: len 1; hex 01; asc  ;;

But in child table `freelumaartists`.`concept_images`, in index uploaded_by, there is a record:
PHYSICAL RECORD: n_fields 2; compact format; info bits 0
 0: len 4; hex 80000004; asc     ;;
 1: len 4; hex 80000012; asc     ;;

------------
TRANSACTIONS
------------
Trx id counter 30579321
Purge done for trx's n:o < 30579321 undo n:o < 0 state: running but idle
History list length 4
LIST OF TRANSACTIONS FOR EACH SESSION:
---TRANSACTION 283725376028888, not started
0 lock struct(s), heap size 1128, 0 row lock(s)
---TRANSACTION 283725376024720, 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
442594423 OS file reads, 10260223 OS file writes, 5643340 OS fsyncs
0.00 reads/s, 0 avg bytes/read, 0.00 writes/s, 0.00 fsyncs/s
-------------------------------------
INSERT BUFFER AND ADAPTIVE HASH INDEX
-------------------------------------
Ibuf: size 1, free list len 353, seg size 355, 78607 merges
merged operations:
 insert 740795, delete mark 1325442, delete 92367
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 2 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)
0.83 hash searches/s, 0.50 non-hash searches/s
---
LOG
---
Log sequence number 3539591545
Log flushed up to   3539591545
Pages flushed up to 3539591545
Last checkpoint at  3539591536
0 pending log flushes, 0 pending chkp writes
4638038 log i/o's done, 0.00 log i/o's/second
----------------------
BUFFER POOL AND MEMORY
----------------------
Total large memory allocated 33554432
Dictionary memory allocated 307992
Buffer pool size   1003
Free buffers       715
Database pages     279
Old database pages 0
Modified db pages  0
Percent of dirty pages(LRU & free pages): 0.000
Max dirty pages percent: 75.000
Pending reads 0
Pending writes: LRU 0, flush list 0, single page 0
Pages made young 676167183, not young 4011278543
0.00 youngs/s, 0.00 non-youngs/s
Pages read 442594352, created 116606, written 5284695
0.00 reads/s, 0.00 creates/s, 0.00 writes/s
Buffer pool hit rate 1000 / 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: 279, unzip_LRU len: 0
I/O sum[23]:cur[0], unzip sum[0]:cur[0]
--------------
ROW OPERATIONS
--------------
0 queries inside InnoDB, 0 queries in queue
0 read views open inside InnoDB
Process ID=7404, Main thread ID=7916, state: sleeping
Number of rows inserted 3422355, updated 382301, deleted 1912672, read 103566019256
0.00 inserts/s, 0.00 updates/s, 0.00 deletes/s, 0.83 reads/s
Number of system rows inserted 0, updated 0, deleted 0, read 246194
0.00 inserts/s, 0.00 updates/s, 0.00 deletes/s, 0.00 reads/s
----------------------------
END OF INNODB MONITOR OUTPUT
============================