Performance Monitor statistics

SQL Anywhere makes a large variety of statistics available. Rates are reported in 1 second intervals. The statistics are grouped into the following areas:

Cache statistics

These statistics describe the use of the cache.

Statistic Scope Description
Cache Hits/sec Connection and database Shows the rate at which database page lookups are satisfied by finding the page in the cache.
Cache Reads: Index Interior/sec Connection and database Shows the rate at which index internal-node pages are read from the cache.
Cache Reads: Index Leaf/sec Connection and database Shows the rate at which index leaf pages are read from the cache.
Cache Reads: Table/sec Connection and database Shows the rate at which table pages are read from the cache.
Cache Reads: Total Pages/sec Connection and database Shows the rate at which database pages are looked up in the cache.
Cache Reads: Work Table Connection and database Shows the rate at which work table pages are being read from the cache.
Cache Replacements: Total Pages/sec Server Shows the rate at which database pages are being purged from the cache to make room for another page that is needed.
Cache Size: Current Server Shows the current size of the database server cache, in kilobytes.
Cache Size: Maximum Server Shows the maximum allowed size of the database server cache, in kilobytes.
Cache Size: Minimum Server Shows the minimum allowed size of the database server cache, in kilobytes.
Cache Size: Peak Server Shows the peak size of the database server cache, in kilobytes.
Checkpoint and recovery statistics

These statistics isolate the checkpoint and recovery actions performed when the database is in an idle state.

Statistic Scope Description
Checkpoint Flushes/sec Database Shows the rate at which ranges of adjacent pages are written out during a checkpoint.
Checkpoint Urgency Database Shows the checkpoint urgency, expressed as a percentage.
Checkpoints/sec Database Shows the rate at which checkpoints are performed.
ChkptLog: Bitmap size Database Shows the size of the checkpoint log bitmap.
ChkptLog: Commit to disk/sec Database Shows the rate at which checkpoint log commit_to_disk operations are being performed.
ChkptLog: Log size Database Shows the size of the checkpoint log in pages.
ChkptLog: Page images saved/sec Database Shows the rate at which pages are being saved in the checkpoint log prior to modification.
ChkptLog: Pages in use Database Shows the number of pages in the checkpoint log which are currently in use.
ChkptLog: Relocate pages/sec Database Shows the rate at which pages in the checkpoint log are being relocated.
ChkptLog: Save preimage/sec Database Shows the rate at which new database page preimages are being added to the checkpoint log.
ChkptLog: Write pages/sec Database Shows the rate at which pages are being written to the checkpoint log.
ChkptLog: Writes/sec Database Shows the rate at which disk writes are being performed in the checkpoint log. One write can include multiple pages.
ChkptLog: Writes to bitmap/sec Database Shows the rate at which disk writes are being performed in the checkpoint log for bitmap pages.
Idle Actives/sec Database Shows the rate at which the database server's idle thread becomes active to do idle writes, idle checkpoints, and so on.
Idle Checkpoint Time Database Shows the total time spent doing idle checkpoints, in seconds.
Idle Checkpoints/sec Database Shows the rate at which checkpoints are completed by the database server's idle thread. An idle checkpoint occurs whenever the idle thread writes out the last dirty page in the cache.
Idle Writes/sec Database Shows the rate at which disk writes are issued by the database server's idle thread.
Recovery I/O Estimate Database Shows the estimated number of I/O operations required to recover the database.
Recovery Urgency Database Shows the recovery urgency expressed as a percentage.
Communications statistics

These statistics describe client/server communications activity.

Statistic Scope Description
Comm: Bytes Received/sec Connection and server Shows the rate at which network data (in bytes) are received.
Comm: Bytes Received Uncompressed/sec Connection and server Shows the rate at which bytes would have been received if compression was disabled.
Comm: Bytes Sent/sec Connection and server Shows the rate at which bytes are transmitted over the network.
Comm: Bytes Sent Uncompressed/sec Connection and server Shows the rate at which bytes would have been sent if compression was disabled.
Comm: Free Buffers Server Shows the number of free network buffers.
Comm: Multi-packets Received/sec Server Shows the rate at which multi-packet deliveries are received.
Comm: Multi-packets Sent/sec Server Shows the rate at which multi-packet deliveries are transmitted.
Comm: Packets Received/sec Connection and server Shows the rate at which network packets are received.
Comm: Packets Received Uncompressed/sec Connection and server Shows the rate at which network packets would have been received if compression was disabled.
Comm: Packets Sent/sec Connection and server Shows the rate at which network packets are transmitted.
Comm: Packets Sent Uncompressed/sec Connection and server Shows the rate at which network packets would have been transmitted if compression was disabled.
Comm: Remoteput Waits/sec Server Shows the rate at which the communication link must wait because it does not have buffers available to send information. This statistic is collected for TCP/IP only.
Comm: Requests Received Connection and server Shows the number of client/server communication requests or round-trips. It is different from the Comm: Packets Received statistic in that multi-packet requests count as one request, and liveness packets are not included.
Comm: Send Fails/sec Server Shows the rate at which the underlying protocol(s) failed to send a packet.
Comm: Total Buffers Server Shows the total number of network buffers.
Comm: Unique Client Addresses Server Shows the number of unique client network addresses connected to the database server. This is usually the number of client machines connected, and may be less than the total number of connections.
Disk I/O statistics

These statistics combine disk reads and disk writes to give overall information about the amount of activity devoted to disk I/O.

Statistic Scope Description
Disk: Active I/Os Database Shows the current number of file I/Os issued by the database server which have not yet completed.
Disk: Maximum Active I/Os Database Shows the maximum value "Disk: Active I/Os" has reached.
Disk read statistics

These statistics describe the amount and type of activity devoted to reading information from disk.

Statistic Scope Description
Disk Reads: Total Pages/sec Connection and database Shows the rate at which pages are read from a file.
Disk Reads: Active Database Shows the current number of file reads issued by the database server which haven't yet completed.
Disk Reads: Index interior/sec Connection and database Shows the rate at which index internal-node pages are being read from disk.
Disk Reads: Index leaf/sec Connection and database Shows the rate at which index leaf pages are being read from disk.
Disk Reads: Table/sec Connection and database Shows the rate at which table pages are being read from disk.
Disk Reads: Maximum Active Database Shows the maximum value "Disk Reads: Active" has reached.
Disk Reads: Work Table Connection and database Shows the rate at which work table pages are being read from disk.
Disk write statistics

These statistics describe the amount and type of activity devoted to writing information to disk.

Statistic Scope Description
Disk Writes: Active Database Shows the current number of file writes issued by the database server that aren't yet completed.
Disk Writes: Maximum Active Database Shows the maximum value "Disk Writes: Active" has reached.
Disk Writes: Commit Files/sec Database Shows the rate at which the database server forces a flush of the disk cache. Windows platforms use unbuffered (direct) I/O, so the disk cache doesn't need to be flushed.
Disk Writes: Database Extends/sec Database Shows the rate at which the database file is extended, in pages/sec.
Disk Writes: Temp Extends/sec Database Shows the rate at which temporary files are extended, in pages/sec.
Disk Writes: Pages/sec Connection and database Shows the rate at which modified pages are being written to disk.
Disk Writes: Transaction Log/sec Connection and database Shows the rate at which pages are written to the transaction log.
Translog Group Commits/sec Connection and database Shows the rate at which a commit of the transaction log was requested but the log had already been written (so the commit was done for free).
Index statistics

These statistics describe the use of the index.

Statistic Scope Description
Index: Adds/sec Connection and database Shows the rate at which entries are added to indexes.
Index: Lookups/sec Connection and database Shows the rate at which entries are looked up in indexes.
Index: Full Compares/sec Connection and database Shows the rate at which comparisons beyond the hash value in an index must be performed.
Memory diagnostic statistics

These statistics describe how the database server is using memory.

Statistic Scope Description
Cache: Multi-Page Allocations Server Shows the number of multi-page allocations.
Cache: Panics Server Shows the number of times the cache manager has failed to find a page to allocate.
Cache: Scavenge Visited Server Shows the number of pages visited while scavenging for a page to allocate.
Cache: Scavenges Server Shows the number of times the cache manager has scavenged for a page to allocate.
Cache Pages: Allocated Structures Server Shows the number of cache pages that have been allocated for database server data structures.
Cache Pages: File Server Shows the number of cache pages used to hold data from database files.
Cache Pages: File Dirty Server Shows the number of cache pages that are dirty (needing a write).
Cache Pages: Free Server Shows the number of cache pages not being used.
Cache Pages: Pinned Server Shows the number of pages currently unavailable for reuse.
Cache Replacements: Total Pages/sec Server Shows the rate at which database pages are being purged from the cache to make room for another page that is needed.
Heaps: Carver Connection and server Shows the number of heaps used for short-term purposes such as query optimization..
Heaps: Query Processing Connection and server Shows the number of heaps used for query processing (hash and sort operations).
Heaps: Relocatable Connection and server Shows the number of relocatable heaps.
Heaps: Relocatable Locked Connection and server Shows the number of relocatable heaps currently locked in the cache.
Map physical memory/sec Server Shows the rate at which database page address space windows are being mapped to physical memory in the cache using Address Windowing Extensions.
Mem Pages: Carver Connection and server Shows the number of heap pages used for short-term purposes such as query optimization.
Mem Pages: Pinned Cursor Server Shows the number of pages used to keep cursor heaps pinned in memory.
Mem Pages: Query Processing Connection and server Shows the number of cache pages used for query processing (hash and sort operations).
Query Memory: Current Active Connection and server Shows the current number of requests actively using query memory.
Query Memory: Estimated Active Server Shows the database server's estimate of the steady state average of the number of requests actively using query memory.
Query Memory: Extra Available Server Shows the amount of memory available to grant beyond the base memory-intensive grant.
Query Memory: Number of Grant Fails Connection and server Shows the total number of times any request waited for query memory and failed to get it.
Query Memory: Number of Grant Requests Connection and server Shows the total number of times any request attempted to acquire query memory.
Query Memory: Number of Grant Waits Connection and server Shows the total number of times any request waited for memory.
Query Memory: Pages Granted Connection and server Shows the number of pages currently granted to requests.
Query Memory: Requests Waiting Connection and server Shows the current number of requests waiting for query memory.
Memory pages statistics

These statistics describe the amount and purpose of memory used by the database server.

Statistic Scope Description
Mem Pages: Lock Table Database Shows the number of pages used to store lock information.
Mem Pages: Locked Heap Server Shows the number of heap pages locked in the cache.
Mem Pages: Main Heap Server Shows the number of pages used for global database server data structures.
Mem Pages: Map Pages Database Shows the number of map pages used for accessing the lock table, frequency table, and table layout.
Mem Pages: Procedure Definitions Database Shows the number of relocatable heap pages used for procedures.
Mem Pages: Relocatable Database Shows the number of pages used for relocatable heaps (cursors, statements, procedures, triggers, views, and so on).
Mem Pages: Relocations/sec Database Shows the rate at which relocatable heap pages are read from the temporary file.
Mem Pages: Rollback Log Connection and database Shows the number of pages in the rollback log.
Mem Pages: Trigger Definitions Database Shows the number of relocatable heap pages used for triggers.
Mem Pages: View Definitions Database Shows the number of relocatable heap pages used for views.
Request statistics

These statistics describe the database server activity devoted to responding to requests from client applications.

Statistic Scope Description
Cursors Connection Shows the number of declared cursors currently maintained by the database server.
Cursors Open Connection Shows the number of open cursors currently maintained by the database server.
Lock Count Connection and database Shows the number of locks.
Requests/sec Server Shows the rate at which the database server is entered to allow it to handle a new request or continue processing an existing request.
Requests: Active Server Shows the number of database server threads that are currently handling a request.
Tasks: Exchange Server Shows the number of database server threads that are currently being used for parallel execution of a query.
Requests: Unscheduled Server Shows the number of requests that are currently queued up waiting for an available database server thread.
Snapshot Count Connection and database Shows the number of active snapshots.
Statement Cache Hits Connection and server Shows the rate at which statement prepares cached by the client are being re-used by the database server.
Statement Cache Misses Connection and server Shows the rate at which statement prepares cached by the client need to be prepared again by the database server.
Statement Prepares Connection Shows the rate at which statement prepares are being handled by the database server.
Statements Connection Shows the number of prepared statements currently maintained by the database server.
Transaction Commits Connection Shows the rate at which Commit requests are handled.
Transaction Rollbacks Connection Shows the rate at which Rollback requests are handled.
Miscellaneous statistics
Statistic Scope Description
Avail IO Server Shows the current number of available I/O control blocks.
Connection Count Database Shows the number of connections to this database.
Main Heap Bytes Server Shows the number of bytes used for global database server data structures.
Query: Plan cache pages Connection and database Shows the number of pages used to cache execution plans.
Query: Low memory strategies Connection and database Shows the number of times the database server changed its execution plan during execution because of low memory conditions.
Query: Rows materialized/sec Connection and database Shows the rate at which rows are written to work tables during query processing.
Requests: GET DATA/sec Connection and database Shows the rate at which a connection is issuing GET DATA requests.
Temporary Table Pages Connection and database Shows the number of pages in the temporary file used for temporary tables.
Version Store Pages Database Shows the number of pages of the temporary file currently being used for the row version store when snapshot isolation is enabled.