20.30.4. The `INFORMATION_SCHEMA INNODB_TRX` Table

The INNODB_TRX table contains information about every transaction currently executing inside InnoDB, including whether the transaction is waiting for a lock, when the transaction started, and the SQL statement the transaction is executing.

Table 20.4. INNODB_TRX Columns

Column name	Description
`TRX_ID`	Unique transaction ID number, internal to `InnoDB`. (Starting in MySQL 5.6, these IDs are not created for transactions that are read-only and non-locking. See Section 14.2.4.2.3, "Optimizations for Read-Only Transactions" for details.)
`TRX_WEIGHT`	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, `InnoDB` selects the transaction with the smallest weight as the "victim" to rollback. Transactions that have changed non-transactional tables are considered heavier than others, regardless of the number of altered and locked rows.
`TRX_STATE`	Transaction execution state. One of `RUNNING`, `LOCK WAIT`, `ROLLING BACK` or `COMMITTING`.
`TRX_STARTED`	Transaction start time.
`TRX_REQUESTED_LOCK_ID`	ID of the lock the transaction is currently waiting for (if `TRX_STATE` is `LOCK WAIT`, otherwise `NULL`). Details about the lock can be found by joining with `INNODB_LOCKS` on `LOCK_ID`.
`TRX_WAIT_STARTED`	Time when the transaction started waiting on the lock (if `TRX_STATE` is `LOCK WAIT`, otherwise `NULL`).
`TRX_MYSQL_THREAD_ID`	MySQL thread ID. Can be used for joining with `PROCESSLIST` on `ID`. See Section 14.2.4.3.4.3, "Possible Inconsistency with `PROCESSLIST`".
`TRX_QUERY`	The SQL query that is being executed by the transaction.
`TRX_OPERATION_STATE`	The transaction's current operation, or `NULL`.
`TRX_TABLES_IN_USE`	The number of InnoDB tables used while processing the current SQL statement of this transaction.
`TRX_TABLES_LOCKED`	Number of InnoDB tables 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.)
`TRX_LOCK_STRUCTS`	The number of locks reserved by the transaction.
`TRX_LOCK_MEMORY_BYTES`	Total size taken up by the lock structures of this transaction in memory.
`TRX_ROWS_LOCKED`	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.
`TRX_ROWS_MODIFIED`	The number of modified and inserted rows in this transaction.
`TRX_CONCURRENCY_TICKETS`	A value indicating how much work the current transaction can do before being swapped out, as specified by the `innodb_concurrency_tickets` option.
`TRX_ISOLATION_LEVEL`	The isolation level of the current transaction.
`TRX_UNIQUE_CHECKS`	Whether unique checks are turned on or off for the current transaction. (They might be turned off during a bulk data load, for example.)
`TRX_FOREIGN_KEY_CHECKS`	Whether foreign key checks are turned on or off for the current transaction. (They might be turned off during a bulk data load, for example.)
`TRX_LAST_FOREIGN_KEY_ERROR`	Detailed error message for last FK error, or `NULL`.
`TRX_ADAPTIVE_HASH_LATCHED`	Whether or not the adaptive hash index is locked by the current transaction. (Only a single transaction at a time can modify the adaptive hash index.)
`TRX_ADAPTIVE_HASH_TIMEOUT`	Whether to relinquish the search latch immediately for the adaptive hash index, or reserve it across calls from MySQL. When there is no AHI 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.
`TRX_IS_READ_ONLY`	A value of 1 indicates the transaction is read-only. (5.6.4 and up.)
`TRX_AUTOCOMMIT_NON_LOCKING`	A value of 1 indicates the transaction is a `SELECT` statement that does not use the `FOR UPDATE` or `LOCK IN SHARED MODE` clauses, and is executing with the `autocommit` setting turned on so that the transaction will only contain this one statement. (5.6.4 and up.) When this column and `TRX_IS_READ_ONLY` are both 1, `InnoDB` optimizes the transaction to reduce the overhead associated with transactions that change table data.

Notes:

Use this table to help diagnose performance problems that occur during times of heavy concurrent load. Its contents are updated as described in Section 14.2.4.3.4.2, "Granularity of INFORMATION_SCHEMA Data".
You must have the PROCESS privilege to query this table.
For usage information, see Section 14.2.4.3.2.1, "Using the Transaction Information Schema Tables".

20.30.4. The INFORMATION_SCHEMA INNODB_TRX Table

20.30.4. The `INFORMATION_SCHEMA INNODB_TRX` Table