bytes received via SQL*Net from client: Total number of bytes received from the client over Oracle Net Services

bytes received via SQL*Net from dblink: Total number of bytes received from a database link over Oracle Net Services

bytes sent via SQL*Net to client: Total number of bytes sent to the client from the foreground processes

bytes sent via SQL*Net to dblink: Total number of bytes sent over a database link

CPU used by this session: Amount of CPU time (in 10s of milliseconds) used by a session from the time a user call starts until it ends. If a user call completes within 10 milliseconds, the start and end user-call time are the same for purposes of this statistics, and 0 milliseconds are added.

db block changes: Closely related to consistent changes, this statistic counts the total number of changes that were part of an update or delete operation that were made to all blocks in the SGA. Such changes generate redo log entries and hence become permanent changes to the database if the transaction is committed.This approximates total database work. It statistic indicates the rate at which buffers are being dirtied (on a per-transaction or per-second basis, for example).

db block gets: The number of times a CURRENT block was requested. See Also: consistent gets

db block gets from cache: The number of times a CURRENT block was requested from the buffer cache. This is a subset of db block gets statistics value.

DBWR checkpoint buffers written: The number of buffers that were written for checkpoints

DBWR checkpoints: The number of times the DBWR was asked to scan the cache and write all blocks marked for a checkpoint or the end of recovery. This statistic is always larger than background checkpoints completed.

DML statements parallelized: The number of DML statements that were executed in parallel.

enqueue conversions: Total number of conversions of the state of table or row lock.

enqueue deadlocks: Total number of deadlocks between table or row locks in different sessions.

enqueue releases: Total number of table or row locks released.

enqueue requests: Total number of table or row locks acquired.

enqueue timeouts: Total number of table and row locks (acquired and converted) that timed out before they could complete.

enqueue waits: Total number of waits that occurred during an enqueue convert or get because the enqueue get was deferred

exchange deadlocks: The number of times that a process detected a potential deadlock when exchanging two buffers and raised an internal, restartable error. Index scans are the only operations that perform exchanges.

execute count: Total number of calls (user and recursive) that executed SQL statements.

gc current block receive time: The total time required for consistent read requests to complete. It records the round-trip time for all requests for consistent read blocks.

index fast full scans (direct read): The number of fast full scans initiated using direct read.

index fast full scans (full): The number of fast full scans initiated for full segments.

index fast full scans (rowid ranges): The number of fast full scans initiated with rowid endpoints specified.

lob reads: The number of LOB API read operations performed in the session/system. A single LOB API read may correspond to multiple physical/logical disk block reads.

lob writes: The number of LOB API write operations performed in the session/system. A single LOB API write may correspond to multiple physical/logical disk block writes.

logons current: Total number of current logons. Useful only in V$SYSSTAT.

Number of Small Reads: The total number ofphysical readsless the number ofphysical read total multi block requests.

Number of Small Writes: The total number ofphysical writesless the number ofphysical write total multi block requests.

opened cursors current: Total number of current open cursors.

Parallel operations not downgraded: The number of times parallel execution was executed at the requested degree of parallelism.

parse count (hard): Total number of parse calls (real parses). A hard parse is a very expensive operation in terms of memory use, because it requires Oracle to allocate a workheap and other memory structures and then build a parse tree.

parse count (total): Total number of parse calls (hard and soft). A soft parse is a check on an object already in the shared pool, to verify that the permissions on the underlying object have not changed.

parse time cpu: Total CPU time used for parsing (hard and soft) in 10s of milliseconds.

parse time elapsed: Total elapsed time for parsing, in 10s of milliseconds. Subtract parse time cpu from this statistic to determine the total waiting time for parse resources.

physical read bytes: Total size in bytes of all disk reads by application activity (and not other instance activity) only.

physical read IO requests: The number of read requests for application activity (mainly buffer cache and direct load operation) which read one or more database blocks per request. This is a subset of physical read total IO requests statistic.

physical read total bytes: Total size in bytes of disk reads by all database instance activity including application reads, backup and recovery, and other utilities. The difference between this value and physical read bytes gives the total read size in bytes by non-application workload.

physical read total IO requests: The number of read requests which read one or more database blocks for all instance activity including application, backup and recovery, and other utilities. The difference between this value and physical read total multi block requests gives the total number of single block read requests.

physical reads: Total number of data blocks read from disk. This value can be greater than the value of physical reads direct plus physical reads cache as reads into process private buffers also included in this statistic.

physical write bytes: Total size in bytes of all disk writes from the database application activity (and not other kinds of instance activity).

physical write IO requests: The number of write requests for application activity (mainly buffer cache and direct load operation) which wrote one or more database blocks per request.

physical write total bytes: Total size in bytes of all disk writes for the database instance including application activity, backup and recovery, and other utilities. The difference between this value and physical write bytes gives the total write size in bytes by non-application workload.

physical write total IO requests: The number of write requests which wrote one or more database blocks from all instance activity including application activity, backup and recovery, and other utilities. The difference between this stat and physical write total multi block requests gives the number of single block write requests.

physical writes: Total number of data blocks written to disk. This statistics value equals the sum of physical writes direct and physical writes from cache values.

physical writes direct: The number of writes directly to disk, bypassing the buffer cache (as in a direct load operation).

physical writes from cache: Total number of data blocks written to disk from the buffer cache. This is a subset of physical writes statistic.

process last non-idle time: The last time this process executed.

queries parallelized: The number of SELECT statements executed in parallel.

Read Percent:

recovery blocks read: The number of blocks read during recovery.

recursive calls: The number of recursive calls generated at both the user and system level. Oracle maintains tables used for internal processing. When Oracle needs to make a change to these tables, it internally generates an internal SQL statement, which in turn generates a recursive call.

recursive cpu usage: Total CPU time used by non-user calls (recursive calls). Subtract this value from CPU used by this session to determine how much CPU time was used by the user calls.

redo blocks written: This is the total number of redo blocks written. This statistic divided by "redo writes" equals the number of blocks per write.

redo buffer allocation retries: Total number of retries necessary to allocate space in the redo buffer. Retries are needed either because the redo writer has fallen behind or because an event such as a log switch is occurring.

redo log space requests: The number of times the active log file is full and Oracle must wait for disk space to be allocated for the redo log entries. Such space is created by performing a log switch.

redo log space wait time: Total elapsed waiting time for redo log space requests in 10s of milliseconds.

redo size: Total amount of redo generated in bytes.

redo synch time: Elapsed time of all redo synch writes calls in 10s of milliseconds

redo write time: Total elapsed time of the write from the redo log buffer to the current redo log file in microseconds.

redo writes: Total number of writes by LGWR to the redo log files. redo blocks written divided by this statistic equals the number of blocks per write.

session cursor cache count: Total number of cursors cached. This statistic is incremented only if SESSION_CACHED_CURSORS > 0. This statistic is the most useful in V$SESSTAT. If the value for this statistic in V$SESSTAT is close to the setting of the SESSION_CACHED_CURSORS parameter, the value of the parameter should be increased.

session cursor cache hits: The number of hits in the session cursor cache. A hit means that the SQL statement did not have to be reparsed. Subtract this statistic from parse count (total) to determine the real number of parses that occurred.

session logical reads: The sum of db block gets plus consistent gets. This includes logical reads of database blocks from either the buffer cache or process private memory.

session stored procedure space: Amount of memory this session is using for stored procedures.

Small IO Percent:I/O operations with a smaller size, such as single-block reads or writes.

sorts (disk): The number of sort operations that required at least one disk write.

sorts (memory): The number of sort operations that were performed completely in memory and did not require any disk writes.

sorts (rows): Total number of rows sorted.

table scan rows gotten: The number of rows that are processed during scanning operations.

table scans (direct read): The number of table scans performed with direct read (bypassing the buffer cache).

table scans (long tables): Long (or conversely short) tables can be defined as tables that do not meet the short table criteria as described in table scans (short tables).

table scans (rowid ranges): During a parallel query, the number of table scans conducted with specified ROWID ranges.

transaction lock background get time: Useful only for internal debugging purposes.

transaction lock foreground wait time: Useful only for internal debugging purposes.

transaction rollbacks: The number of transactions being successfully rolled back.

Total Lock Time: Total lock time is calculated based on the number of blocking sessions per second granularity. This does not consider the duration when a transaction is rolled back during a session-level or server-level lock timeout.

user calls: The number of user calls such as login, parse, fetch, or execute

user commits: The number of user commits. When a user commits a transaction, the redo generated that reflects the changes made to database blocks must be written to disk. Commits often represent the closest thing to a user transaction rate.

user rollbacks: The number of times users manually issue the ROLLBACK statement or an error occurs during a user's transactions.

DB|Server Statistic|DB time: The sum of CPU consumption of all the Oracle process and the sum of non-idle wait time

DB|Server Statistic|OS System time used: The total CPU time used for system calls

DB|Server Statistic|OS User time used: The total CPU time used for user calls

DB|Server Statistic|SMON posted for instance recovery: The total count or number of times SMON posted for instance recovery

DB|Server Statistic|SMON posted for txn recovery for other instances: The total count or number of times SMON posted for other transactions recovery in an Oracle RAC or a cluster

DB|Server Statistic|java call heap live size: The Java call heap live size

DB|Server Statistic|java call heap total size: The total Java call heap size

DB|Server Statistic|java call heap used size: The Java call heap used size

DB|Server Statistic|non-idle wait count: The total count of non-idle wait events

DB|Server Statistic|non-idle wait time: The total elapsed time for non-idle events

Performance Metrics