MySQL8.0 Reference Manual
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TheINNODB_TRXtable provides information about every transaction currently executing insideInnoDB, including whether the transaction is waiting for a lock, when the transaction started, and the SQL statement the transaction is executing, if any.

For usage information, seeSection, “Using InnoDB Transaction and Locking Information”

TheINNODB_TRXtable has these columns:

  • TRX_ID

    A unique transaction ID number, internal toInnoDB。这些id并不创建交易are read only and nonlocking. For details, seeSection 8.5.3, “Optimizing InnoDB Read-Only Transactions”


    The weight of a transaction, reflecting (but not necessarily the exact count of) the number of rows altered and the number of rows locked by the transaction. To resolve a deadlock,InnoDBselects the transaction with the smallest weight as thevictimto roll back. Transactions that have changed nontransactional tables are considered heavier than others, regardless of the number of altered and locked rows.


    The transaction execution state. Permitted values areRUNNING,LOCK WAIT,ROLLING BACK, andCOMMITTING


    The transaction start time.


    The ID of the lock the transaction is currently waiting for, ifTRX_STATEisLOCK WAIT; otherwiseNULL。To obtain details about the lock, join this column with theENGINE_LOCK_IDcolumn of the Performance Schemadata_lockstable.


    The time when the transaction started waiting on the lock, ifTRX_STATEisLOCK WAIT; otherwiseNULL


    The MySQL thread ID. To obtain details about the thread, join this column with theIDcolumn of theINFORMATION_SCHEMAPROCESSLISTtable, but seeSection, “Persistence and Consistency of InnoDB Transaction and Locking Information”


    The SQL statement that is being executed by the transaction.


    The transaction's current operation, if any; otherwiseNULL


    The number ofInnoDBtables used while processing the current SQL statement of this transaction.


    The number ofInnoDBtables that the current SQL statement has row locks on. (Because these are row locks, not table locks, the tables can usually still be read from and written to by multiple transactions, despite some rows being locked.)


    The number of locks reserved by the transaction.


    The total size taken up by the lock structures of this transaction in memory.


    The approximate number or rows locked by this transaction. The value might include delete-marked rows that are physically present but not visible to the transaction.


    The number of modified and inserted rows in this transaction.


    A value indicating how much work the current transaction can do before being swapped out, as specified by theinnodb_concurrency_ticketssystem variable.


    The isolation level of the current transaction.


    Whether unique checks are turned on or off for the current transaction. For example, they might be turned off during a bulk data load.


    Whether foreign key checks are turned on or off for the current transaction. For example, they might be turned off during a bulk data load.


    The detailed error message for the last foreign key error, if any; otherwiseNULL


    Whether the adaptive hash index is locked by the current transaction. When the adaptive hash index search system is partitioned, a single transaction does not lock the entire adaptive hash index. Adaptive hash index partitioning is controlled byinnodb_adaptive_hash_index_parts, which is set to 8 by default.


    Whether to relinquish the search latch immediately for the adaptive hash index, or reserve it across calls from MySQL. When there is no adaptive hash index contention, this value remains zero and statements reserve the latch until they finish. During times of contention, it counts down to zero, and statements release the latch immediately after each row lookup. When the adaptive hash index search system is partitioned (controlled byinnodb_adaptive_hash_index_parts), the value remains 0.


    A value of 1 indicates the transaction is read only.


    A value of 1 indicates the transaction is aSELECTstatement that does not use theFOR UPDATEorLOCK IN SHARED MODEclauses, and is executing withautocommitenabled so that the transaction contains only this one statement. When this column andTRX_IS_READ_ONLYare both 1,InnoDBoptimizes the transaction to reduce the overhead associated with transactions that change table data.


    The transaction schedule weight assigned by the Contention-Aware Transaction Scheduling (CATS) algorithm to transactions waiting for a lock. The value is relative to the values of other transactions. A higher value has a greater weight. A value is computed only for transactions in aLOCK WAITstate, as reported by theTRX_STATEcolumn. A NULL value is reported for transactions that are not waiting for a lock. TheTRX_SCHEDULE_WEIGHTvalue is different from theTRX_WEIGHTvalue, which is computed by a different algorithm for a different purpose.


mysql> SELECT * FROM INFORMATION_SCHEMA.INNODB_TRX\G *************************** 1. row *************************** trx_id: 1510 trx_state: RUNNING trx_started: 2014-11-19 13:24:40 trx_requested_lock_id: NULL trx_wait_started: NULL trx_weight: 586739 trx_mysql_thread_id: 2 trx_query: DELETE FROM employees.salaries WHERE salary > 65000 trx_operation_state: updating or deleting trx_tables_in_use: 1 trx_tables_locked: 1 trx_lock_structs: 3003 trx_lock_memory_bytes: 450768 trx_rows_locked: 1407513 trx_rows_modified: 583736 trx_concurrency_tickets: 0 trx_isolation_level: REPEATABLE READ trx_unique_checks: 1 trx_foreign_key_checks: 1 trx_last_foreign_key_error: NULL trx_adaptive_hash_latched: 0 trx_adaptive_hash_timeout: 10000 trx_is_read_only: 0 trx_autocommit_non_locking: 0 trx_schedule_weight: NULL