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 18.3. INNODB_TRX Columns

Column name Description
TRX_ID Unique transaction ID number, internal to InnoDB.
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 , "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 currently have any locks. (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:

Retornar