Storage engines

InnoDB

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

[ Variables | Buffer Pool | InnoDB Status ]

=====================================
2026-06-22 09:32:04 0x1b08 INNODB MONITOR OUTPUT
=====================================
Per second averages calculated from the last 53 seconds
-----------------
BACKGROUND THREAD
-----------------
srv_master_thread loops: 282298 srv_active, 0 srv_shutdown, 3871884 srv_idle
srv_master_thread log flush and writes: 4154182
----------
SEMAPHORES
----------
OS WAIT ARRAY INFO: reservation count 4433585
OS WAIT ARRAY INFO: signal count 5164603
RW-shared spins 8764403, rounds 172446102, OS waits 3724971
RW-excl spins 2253081, rounds 38648581, OS waits 561671
RW-sx spins 30575, rounds 406294, OS waits 10737
Spin rounds per wait: 19.68 RW-shared, 17.15 RW-excl, 13.29 RW-sx
------------------------
LATEST FOREIGN KEY ERROR
------------------------
2026-06-06 16:25:34 0x6cbc Transaction:
TRANSACTION 8689523, ACTIVE 0 sec inserting
mysql tables in use 1, locked 1
3 lock struct(s), heap size 1128, 1 row lock(s), undo log entries 1
MySQL thread id 7054590, OS thread handle 27836, query id 53885548 hr-pc10 192.168.2.204 charitylog Update
INSERT INTO employees_probation_decisions 
            (ApplicantID, EmpID, EmployeeName, BranchID, JobName, EmploymentDate, DecisionStatus, Notes, CreatedAt)
            VALUES (701, 79, 'محمد عبدالله محمد عبدالله', '', 'ضابط وبائيات بعقد', @NULL, 'مقبول', 'اعتذر بسبب الراتب', timestamp('2026-06-06 16:26:03.518130'))
Foreign key constraint fails for table `jobapplications`.`employees_probation_decisions`:
,
  CONSTRAINT `employees_probation_decisions_ibfk_1` FOREIGN KEY (`BranchID`) REFERENCES `branch_tbl` (`branch_id`) in parent table, in index BranchID tuple:
DATA TUPLE: 2 fields;
 0: len 4; hex 80000000; asc     ;;
 1: len 4; hex 80000019; asc     ;;

But in parent table `jobapplications`.`branch_tbl`, in index PRIMARY,
the closest match we can find is record:
PHYSICAL RECORD: n_fields 4; compact format; info bits 0
 0: len 4; hex 80000001; asc     ;;
 1: len 6; hex 000000000000; asc       ;;
 2: len 7; hex 80000000000000; asc        ;;
 3: len 14; hex d8a7d984d8a5d8afd8a7d8b1d8a9; asc               ;;

------------------------
LATEST DETECTED DEADLOCK
------------------------
2026-05-07 22:27:23 0x5a90
*** (1) TRANSACTION:
TRANSACTION 8027226, ACTIVE 0 sec starting index read
mysql tables in use 1, locked 1
LOCK WAIT 3 lock struct(s), heap size 1128, 3 row lock(s)
MySQL thread id 640794, OS thread handle 21328, query id 4129955 localhost ::1 root Updating
DELETE FROM product_quantities WHERE client_product_id = '1180310'
*** (1) WAITING FOR THIS LOCK TO BE GRANTED:
RECORD LOCKS space id 38206 page no 3424 n bits 120 index PRIMARY of table `inventory_management`.`product_quantities` trx id 8027226 lock_mode X locks rec but not gap waiting
Record lock, heap no 38 PHYSICAL RECORD: n_fields 10; compact format; info bits 32
 0: len 4; hex 802632c9; asc  &2 ;;
 1: len 6; hex 0000007a7c5e; asc    z|^;;
 2: len 7; hex 0e000001ab2444; asc      $D;;
 3: len 4; hex 80120296; asc     ;;
 4: len 8; hex 0000000000003740; asc       7@;;
 5: len 3; hex 8f8c21; asc   !;;
 6: len 5; hex 99b9cf66d7; asc    f ;;
 7: len 5; hex 99b9cf66d7; asc    f ;;
 8: len 4; hex 800007ea; asc     ;;
 9: len 4; hex 80000005; asc     ;;

*** (2) TRANSACTION:
TRANSACTION 8027230, ACTIVE 0 sec updating or deleting
mysql tables in use 1, locked 1
4 lock struct(s), heap size 1128, 4 row lock(s), undo log entries 1
MySQL thread id 640798, OS thread handle 23184, query id 4129965 localhost ::1 root Updating
DELETE FROM product_quantities WHERE client_product_id = '1180310'
*** (2) HOLDS THE LOCK(S):
RECORD LOCKS space id 38206 page no 3424 n bits 120 index PRIMARY of table `inventory_management`.`product_quantities` trx id 8027230 lock_mode X locks rec but not gap
Record lock, heap no 38 PHYSICAL RECORD: n_fields 10; compact format; info bits 32
 0: len 4; hex 802632c9; asc  &2 ;;
 1: len 6; hex 0000007a7c5e; asc    z|^;;
 2: len 7; hex 0e000001ab2444; asc      $D;;
 3: len 4; hex 80120296; asc     ;;
 4: len 8; hex 0000000000003740; asc       7@;;
 5: len 3; hex 8f8c21; asc   !;;
 6: len 5; hex 99b9cf66d7; asc    f ;;
 7: len 5; hex 99b9cf66d7; asc    f ;;
 8: len 4; hex 800007ea; asc     ;;
 9: len 4; hex 80000005; asc     ;;

*** (2) WAITING FOR THIS LOCK TO BE GRANTED:
RECORD LOCKS space id 38206 page no 5409 n bits 256 index fk_client_product_id of table `inventory_management`.`product_quantities` trx id 8027230 lock_mode X locks rec but not gap waiting
Record lock, heap no 177 PHYSICAL RECORD: n_fields 2; compact format; info bits 0
 0: len 4; hex 80120296; asc     ;;
 1: len 4; hex 802632c9; asc  &2 ;;

*** WE ROLL BACK TRANSACTION (1)
------------
TRANSACTIONS
------------
Trx id counter 9446079
Purge done for trx's n:o < 9446079 undo n:o < 0 state: running but idle
History list length 10
LIST OF TRANSACTIONS FOR EACH SESSION:
---TRANSACTION 283708122157560, not started
0 lock struct(s), heap size 1128, 0 row lock(s)
---TRANSACTION 283708122153392, not started
0 lock struct(s), heap size 1128, 0 row lock(s)
---TRANSACTION 283708122149224, not started
0 lock struct(s), heap size 1128, 0 row lock(s)
---TRANSACTION 283708122145056, not started
0 lock struct(s), heap size 1128, 0 row lock(s)
---TRANSACTION 283708122136720, not started
0 lock struct(s), heap size 1128, 0 row lock(s)
---TRANSACTION 283708122140888, 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
153771215 OS file reads, 6275229 OS file writes, 2791301 OS fsyncs
21.26 reads/s, 16384 avg bytes/read, 21.38 writes/s, 10.40 fsyncs/s
-------------------------------------
INSERT BUFFER AND ADAPTIVE HASH INDEX
-------------------------------------
Ibuf: size 1, free list len 379, seg size 381, 175509 merges
merged operations:
 insert 221971, delete mark 127, delete 93
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)
29.72 hash searches/s, 65.56 non-hash searches/s
---
LOG
---
Log sequence number 1071175971182
Log flushed up to   1071175971162
Pages flushed up to 1071175969953
Last checkpoint at  1071175969910
0 pending log flushes, 0 pending chkp writes
1510909 log i/o's done, 6.49 log i/o's/second
----------------------
BUFFER POOL AND MEMORY
----------------------
Total large memory allocated 33554432
Dictionary memory allocated 2974752
Buffer pool size   1003
Free buffers       738
Database pages     257
Old database pages 0
Modified db pages  3
Percent of dirty pages(LRU & free pages): 0.301
Max dirty pages percent: 75.000
Pending reads 0
Pending writes: LRU 0, flush list 0, single page 0
Pages made young 1221699, not young 5520592640
0.00 youngs/s, 0.00 non-youngs/s
Pages read 153770041, created 29835, written 4312982
21.26 reads/s, 0.23 creates/s, 13.09 writes/s
Buffer pool hit rate 976 / 1000, young-making rate 0 / 1000 not 0 / 1000
Pages read ahead 2.42/s, evicted without access 0.00/s, Random read ahead 0.00/s
LRU len: 257, unzip_LRU len: 0
I/O sum[1697]: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=5292, Main thread ID=7324, state: sleeping
Number of rows inserted 673211, updated 508427, deleted 306318, read 4471900058
0.00 inserts/s, 5.26 updates/s, 0.00 deletes/s, 2263.13 reads/s
Number of system rows inserted 0, updated 0, deleted 0, read 0
0.00 inserts/s, 0.00 updates/s, 0.00 deletes/s, 0.00 reads/s
----------------------------
END OF INNODB MONITOR OUTPUT
============================