Event Reports Generated in NDB Cluster interval may have started in a previous reporting interval, it is possible for  Commit count  to be greater than  Trans count . A unique index update operation can generate multiple PK read and write operations on the index table and on the base table. Unique index operations generate multiple PK operations and so increase this count. However, data words sent to describe the PK operation itself, and the key information sent, are  not  counted here. Attribute information sent to describe columns to read for scans, or to describe ScanFilters, is also not counted in  AttrInfoCount . The maximum value that  Concurrent Operations  can have is the maximum number of operations that a TC block can support; currently, this is  (2 * MaxNoOfConcurrentOperations) + 16 + MaxNoOfConcurrentTransactions . (For more information about these configuration parameters, see the  Transaction Parameters  section of Section 23.3.3.6, “Defining NDB Cluster Data Nodes” .) 4473 • Local reads.   This is the number of primary-key read operations performed using a transaction coordinator on a node that also holds the primary fragment replica of the record. This count can also be obtained from the  LOCAL_READS  counter in the  ndbinfo.counters  table. • Range scans.   This is the number of ordered index scans using this TC as the transaction coordinator that were started in the last reporting interval. • Scans.   This is the number of table scans using this TC as the transaction coordinator that were started during the last reporting interval. This does not include range scans (that is, ordered index scans). • Abort count.   This is the number of transactions using this TC as the transaction coordinator that were aborted during the last reporting interval. Because some transactions that were aborted in the last reporting interval may have started in a previous reporting interval,  Abort count  can sometimes be greater than  Trans count . • Concurrent Operations.   This is the number of primary key or scan operations using this TC as the transaction coordinator that were started during the last reporting interval but that were not completed. Operations increment this counter when they are started and decrement it when they are completed; this occurs after the transaction commits. Dirty reads and writes—as well as failed operations—decrement this counter. • AttrInfoCount.   This is the number of 32-bit data words received in the last reporting interval for primary key operations using this TC as the transaction coordinator. For reads, this is proportional to the number of columns requested. For inserts and updates, this is proportional to the number of columns written, and the size of their data. For delete operations, this is usually zero. • Write count.   This is the number of primary key write operations using this TC as the transaction coordinator that were started in the last reporting interval. This includes all inserts, updates, writes and deletes, as well as writes performed as part of unique index operations. • Simple read count.   This is the number of simple read operations using this TC as the transaction coordinator that were started in the last reporting interval. • Read count.   This is the number of primary key read operations using this TC as the transaction coordinator that were started in the last reporting interval, including simple reads. This count also includes reads performed as part of unique index operations. A unique index read operation generates 2 primary key read operations—1 for the hidden unique index table, and 1 for the table on which the read takes place. Note