System Data Collection Sets
The data collector installs three System Data collection sets during the SQL Server 2008 Setup process. These collection sets can be configured to suit your monitoring requirements but cannot be deleted. The System Data collection sets consist of the following:
Disk Usage. Collects data about disk and log usage for all the databases installed on the system.
Server Activity. Collects resource usage statistics and performance data from the server and SQL Server.
Query Statistics. Collects query statistics, individual query text, query plans, and specific queries.
Disk Usage Collection Set
The Disk Usage collection set tracks the growth of database and log files and provides file-related statistics such as the average growth (in megabytes) per day.
The collection set has two collection items, Disk Usage - Data Files and Disk Usage - Log Files. Both use the Generic T-SQL Query collector type. The collection set gathers the following data:
Snapshots of data file sizes obtained from the sys.partitions and sys.allocation_units views.
Snapshots of log file sizes obtained from the DBCC SQLPERF (LOGSPACE) command.
Snapshots of I/O statistics from the sys.dm_io_virtual_file_stats function.
The following tables provide detailed information about the Disk Usage collection set and its collection items.
Collection set name |
Disk Usage |
Collection mode |
Non-cached |
Upload schedule frequency |
Every 6 hours |
Data retention |
730 days |
Collection items |
Disk Usage - Data Files Disk Usage - Log Files |
Collection item name |
Disk Usage - Data Files |
Collector type |
Generic T-SQL Query |
Query 1 |
|
Query 1 output |
disk_usage |
Collection item name |
Disk Usage - Log Files |
Collector type |
Generic T-SQL Query |
Query 1 |
|
Query 1 output |
log_usage |
Server Activity Collection Set
The Server Activity collection set provides an overview of SQL Server activity, SQL Server resource utilization and SQL Server resource contention. The collection set also provides an encapsulated view of overall system resource utilization that enables you to determine if performance issues are related to activities outside the scope of SQL Server.
This collection set collects data samples from the following dynamic management views:
sys.dm_os_wait_stats
sys.dm_os_latch_stats
sys.dm_os_schedulers
sys.dm_exec_sessions, sys.dm_exec_requests, sys.dm_os_waiting_tasks (using a joined query)
sys.dm_os_process_memory
sys.dm_os_memory_nodes
Additionally, data samples are collected from several system and SQL Server performance counters.
The Server Activity collection set gives you an overall view of the system in terms of resource utilization and resource bottlenecks. Resource usage is tracked in four general areas: CPU, Disk I/O, Memory, and Network. The sampling of sys.dm_exec_sessions, sys.dm_exec_requests and sys.dm_os_waiting_tasks enables the correlation of system activity with resource bottlenecks and with blocking problems.
Run on its own, this collection set enables you to associate resource bottlenecks with a blocked session and to show blocking chains at the session level. Although query texts are not collected, you can use the sql_handle and plan_handle information that is collected by the Query Statistics collection set to drill down below the session level.
The following tables provide detailed information about the Server Activity collection set and its collection items.
Collection set name |
Server Activity |
Collection mode |
Cached |
Upload schedule frequency |
Every 15 minutes |
Data retention |
14 days |
Collection items |
Server Activity - DMV Snapshots Server Activity – Performance Counters |
Collection item name |
Server Activity – DMV Snapshots |
Collector type |
Generic T-SQL Query |
Collection frequency |
60 seconds |
Query 1 |
|
Query 1 output |
snapshots.os_wait_stats |
Query 2 |
|
Query 2 output |
snapshots.os_latch_stats |
Query 3 |
|
Query 3 output |
snapshots.sql_process_and_system_memory |
Query 4 |
|
Query 4 output |
snapshots.os_memory_nodes |
Query 5 |
|
Query 5 output |
snapshots.os_memory_clerks |
Query 6 |
|
Query 6 output |
snapshots.os_schedulers |
Query 7 |
|
Query 7 output |
snapshots.io_virtual_file_stats |
Collection item name |
Server Activity – Performance Counters |
Collector type |
Performance Counters |
Collection frequency |
60 seconds |
Performance counters used |
"Memory" Counters="% Committed Bytes In Use" "Memory" Counters="Available Bytes" "Memory" Counters="Cache Bytes" "Memory" Counters="Cache Faults/sec" "Memory" Counters="Committed Bytes" "Memory" Counters="Free & Zero Page List Bytes" "Memory" Counters="Modified Page List Bytes" "Memory" Counters="Pages/sec" "Memory" Counters="Page Reads/sec" "Memory" Counters="Page Write/sec" "Memory" Counters="Page Faults/sec" "Memory" Counters="Pool Nonpaged Bytes" "Memory" Counters="Pool Paged Bytes" "Memory" Counters="Standby Cache Core Bytes" "Memory" Counters="Standby Cache Normal Priority Bytes" "Memory" Counters="Standby Cache Reserve Bytes" "Memory" Counters="Pool Paged Bytes" "Memory" Counters="Write Copies/sec" "Process" Counters="*" Instances="_Total" "Process" Counters="*" Instances="$(TARGETPROCESS)" "Process" Counters="Thread Count" Instances="*" "Process" Counters="% Processor Time" Instances="*" "Process" Counters="IO Read Bytes/sec" Instances="*" "Process" Counters="IO Write Bytes/sec" Instances="*" "Process" Counters="Private Bytes" Instances="*" "Process" Counters="Working Set" Instances="*" "Processor" Counters="% Processor Time" Instances="*" "Processor" Counters="% User Time" Instances="*" "Processor" Counters="% Privileged Time" Instances="*" "Server Work Queues" Counters="Queue Length" Instances="*" "LogicalDisk" Counters="% Disk Time" Instances="*" "LogicalDisk" Counters="Avg. Disk Queue Length" Instances="*" "LogicalDisk" Counters="Avg. Disk Read Queue Length" Instances="*" "LogicalDisk" Counters="Avg. Disk Write Queue Length" Instances="*" "LogicalDisk" Counters="Avg. Disk sec/Read" Instances="*" "LogicalDisk" Counters="Avg. Disk sec/Write" Instances="*" "LogicalDisk" Counters="Avg. Disk sec/Transfer" Instances="*" "LogicalDisk" Counters="Disk Reads/sec" Instances="*" "LogicalDisk" Counters="Disk Bytes/sec" Instances="*" "LogicalDisk" Counters="Disk Writes/sec" Instances="*" "LogicalDisk" Counters="Split IO/sec" Instances="*" "System" Counters="Processor Queue Length" "System" Counters="File Read Operations/sec" "System" Counters="File Write Operations/sec" "System" Counters="File Control Operations/sec" "System" Counters="File Read Bytes/sec" "System" Counters="File Write Bytes/sec" "System" Counters="File Control Bytes/sec" "Network Interface" Counters="Bytes Total/sec" Instances="*" "Network Interface" Counters="Output Queue Length" Instances="*" "SQLServer:Buffer Manager" Counters="Stolen pages" "SQLServer:Buffer Manager" Counters="Page life expectancy" "SQLServer:Memory Manager" Counters="Memory Grants Outstanding" "SQLServer:Memory Manager" Counters="Memory Grants Pending" "SQLServer:Databases" Counters="Transactions/sec" Instances="_Total" "SQLServer:Databases" Counters="Transactions/sec" Instances="tempdb" "SQLServer:Databases" Counters="Active Transactions" Instances="*" "SQLServer:General Statistics" Counters="Logins/sec" "SQLServer:General Statistics" Counters="Logouts/sec" "SQLServer:General Statistics" Counters="User Connections" "SQLServer:General Statistics" Counters="Logical Connections" "SQLServer:General Statistics" Counters="Transactions" "SQLServer:General Statistics" Counters="Processes blocked" "SQLServer:General Statistics" Counters="Active Temp Tables" "SQLServer:SQL Statistics" Counters="Batch Requests/sec" "SQLServer:SQL Statistics" Counters="SQL Compilations/sec" "SQLServer:SQL Statistics" Counters="SQL Re-Compilations/sec" "SQLServer:SQL Statistics" Counters="SQL Attention rate" "SQLServer:SQL Statistics" Counters="Auto-Param Attempts/sec" "SQLServer:SQL Statistics" Counters="Failed Auto-Params/sec" "SQLServer:Plan Cache" Counters="Cache Hit Ratio" Instances="_Total" "SQLServer:Plan Cache" Counters="Cache Hit Ratio" Instances="Object Plans" "SQLServer:Plan Cache" Counters="Cache Hit Ratio" Instances="SQL Plans" "SQLServer:Plan Cache" Counters="Cache Hit Ratio" Instances="Temporary Tables & Table Variables" "SQLServer:Transactions" Counters="Free Space in tempdb (KB)" "SQLServer:Workload Group Stats" Counters="Active requests" Instances="*" "SQLServer:Workload Group Stats" Counters="Blocked tasks" Instances="*" "SQLServer:Workload Group Stats" Counters="CPU usage %" Instances="*" |
Query Statistics Collection Set
The Query Statistics collection set gathers data about query statistics and individual query text, query plans, and specific queries. This data, when linked with system-level statistics and activities, enables you to drill down below the session level to an individual query.
This collection set collects data from the following sources:
sys.dm_exec_requests, sys.dm_exec_sessions, sys.dm_exec_query_stats and other related dynamic management views.
The text of selected batches and queries.
The plan of selected batches and queries.
The normalized text of selected batches.
The Query Statistics collection set uses the Query Activity collector type. The Query Activity collector type collects data by using the QueryActivityCollect.dtsx SSIS package, and uploads data by using the QueryActivityUpload.dtsx SSIS package. For more information about the collection and upload phases of the Query Activity collection type, including the queries that are used, see Query Activity Collector Type.
The following tables provided information about the Query Statistics collection set and its collection item.
Collection set name |
Query Statistics |
Collection mode |
Cached |
Upload schedule frequency |
Every 15 minutes |
Data retention |
14 days |
Collection item |
Query Statistics - Query Activity |
See Also