Storage engines
InnoDB
Supports transactions, row-level locking, foreign keys and encryption for tables
[ Variables | Buffer Pool | InnoDB Status ]
===================================== 2026-04-09 16:59:30 0x9eb0 INNODB MONITOR OUTPUT ===================================== Per second averages calculated from the last 31 seconds ----------------- BACKGROUND THREAD ----------------- srv_master_thread loops: 2616 srv_active, 0 srv_shutdown, 517930 srv_idle srv_master_thread log flush and writes: 520539 ---------- SEMAPHORES ---------- OS WAIT ARRAY INFO: reservation count 12108 OS WAIT ARRAY INFO: signal count 11135 RW-shared spins 15249, rounds 237688, OS waits 7263 RW-excl spins 10078, rounds 31753, OS waits 83 RW-sx spins 307, rounds 2076, OS waits 22 Spin rounds per wait: 15.59 RW-shared, 3.15 RW-excl, 6.76 RW-sx ------------------------ LATEST FOREIGN KEY ERROR ------------------------ 2026-04-06 11:39:13 0x2fb0 Transaction: TRANSACTION 42590, ACTIVE 0 sec updating or deleting mysql tables in use 1, locked 1 4 lock struct(s), heap size 1128, 2 row lock(s), undo log entries 1 MySQL thread id 99816, OS thread handle 12208, query id 354010 localhost ::1 root Updating DELETE FROM productos WHERE id = ? Foreign key constraint fails for table `ciber_gemelos_db`.`detalle_venta`: , CONSTRAINT `detalle_venta_ibfk_2` FOREIGN KEY (`producto_id`) REFERENCES `productos` (`id`) Trying to delete or update in parent table, in index PRIMARY tuple: DATA TUPLE: 11 fields; 0: len 4; hex 8000014e; asc N;; 1: len 6; hex 00000000a65e; asc ^;; 2: len 7; hex 6b00000146170a; asc k F ;; 3: len 7; hex 50415030313836; asc PAP0186;; 4: len 17; hex 4c6170697a2054696e7461205a65627261; asc Lapiz Tinta Zebra;; 5: len 4; hex 80000003; asc ;; 6: len 5; hex 8000001400; asc ;; 7: len 5; hex 8000001900; asc ;; 8: len 4; hex 80000011; asc ;; 9: len 0; hex ; asc ;; 10: len 4; hex 80000005; asc ;; But in child table `ciber_gemelos_db`.`detalle_venta`, in index producto_id, there is a record: PHYSICAL RECORD: n_fields 2; compact format; info bits 0 0: len 4; hex 8000014e; asc N;; 1: len 4; hex 80000392; asc ;; ------------ TRANSACTIONS ------------ Trx id counter 46056 Purge done for trx's n:o < 46056 undo n:o < 0 state: running but idle History list length 0 LIST OF TRANSACTIONS FOR EACH SESSION: ---TRANSACTION 283872282116312, not started 0 lock struct(s), heap size 1128, 0 row lock(s) ---TRANSACTION 283872282112144, 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 10899 OS file reads, 55241 OS file writes, 30175 OS fsyncs 0.13 reads/s, 16384 avg bytes/read, 0.00 writes/s, 0.00 fsyncs/s ------------------------------------- INSERT BUFFER AND ADAPTIVE HASH INDEX ------------------------------------- Ibuf: size 1, free list len 11, seg size 13, 0 merges merged operations: insert 0, delete mark 0, 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 2 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) 15.00 hash searches/s, 0.00 non-hash searches/s --- LOG --- Log sequence number 27842695 Log flushed up to 27842695 Pages flushed up to 27842695 Last checkpoint at 27842686 0 pending log flushes, 0 pending chkp writes 18879 log i/o's done, 0.00 log i/o's/second ---------------------- BUFFER POOL AND MEMORY ---------------------- Total large memory allocated 33554432 Dictionary memory allocated 162760 Buffer pool size 1003 Free buffers 683 Database pages 310 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 0, not young 0 0.00 youngs/s, 0.00 non-youngs/s Pages read 10831, created 606, written 33203 0.13 reads/s, 0.00 creates/s, 0.00 writes/s Buffer pool hit rate 996 / 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: 310, unzip_LRU len: 0 I/O sum[9]: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=16440, Main thread ID=17600, state: sleeping Number of rows inserted 6989, updated 1156, deleted 7334, read 5327581 0.00 inserts/s, 0.00 updates/s, 0.00 deletes/s, 30.42 reads/s Number of system rows inserted 0, updated 0, deleted 0, read 852 0.00 inserts/s, 0.00 updates/s, 0.00 deletes/s, 0.00 reads/s ---------------------------- END OF INNODB MONITOR OUTPUT ============================