• N_COLS 

The number of columns in the temporary table. The number includes three hidden columns created by InnoDB  ( DB_ROW_ID , DB_TRX_ID , and DB_ROLL_PTR ). 

## Example 

## Notes 

• SPACE 

The ID of the temporary tablespace where the temporary table resides. 

mysql> CREATE TEMPORARY TABLE t1 (c1 INT PRIMARY KEY) ENGINE=INNODB; mysql> SELECT * FROM INFORMATION_SCHEMA.INNODB_TEMP_TABLE_INFO\G *************************** 1. row *************************** TABLE_ID: 97 NAME: #sql8c88_43_0 N_COLS: 4 SPACE: 76 

•This table is useful primarily for expert-level monitoring. 

•You must have the PROCESS  privilege to query this table. 

•Use the INFORMATION_SCHEMA COLUMNS  table or the SHOW COLUMNS  statement to view additional information about the columns of this table, including data types and default values. 

## 26.4.30 The INFORMATION_SCHEMA INNODB_TRX Table 

The INNODB_TRX  table provides 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, if any. 

For usage information, see Section 15.15.2.1, “Using InnoDB Transaction and Locking Information” . 

The INNODB_TRX  table has these columns: 

• TRX_ID 

A unique transaction ID number, internal to InnoDB . These IDs are not created for transactions that are read only and nonlocking. For details, see Section 8.5.3, “Optimizing InnoDB Read-Only Transactions” . 

• 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 roll back. Transactions that have changed nontransactional tables are considered heavier than others, regardless of the number of altered and locked rows. 

• TRX_STATE 

The transaction execution state. Permitted values are RUNNING , LOCK WAIT , ROLLING BACK , and COMMITTING . 

• TRX_STARTED 

