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The Current tab displays information on the last minute of activity. For example, if you've worked at your screen for ten minutes and then refresh the information displayed on your screen, you will be able to view new information that occurred during the last minute of activity. |
See “Analyzing Analyzing locks currently held” on page 73held.
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If you want to view detailed information on a specific session holding lock, click the row of the sessions holding locks you want to view detailed information for. The Tab heading indicates the newly selected entity; the Main area displays locking and In MS-SQL information on the session you drilled down to, and the Association area shows information on the statements associated with this session.
See “About About Precise for SQL Server tabs” on page 22tabs.
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The following table describes the information displayed in the Instance Overview.
Table 5- 1 Instance Overview view
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| Sessions |
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| In MS-SQL (Last minute) | Displays the resource consumption breakdown of the instance during the last minute (that is, 60 samples of the Collector). In addition to the resource distribution, the view displays the number of sessions in each state during the last sample. It is important to remember that since this view only displays the last minute's activities, you will always be viewing the activities that occurred during the last minute and not the activities that occurred since the last refresh action. The following information is displayed:
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See “About session states” on page 36 About session states.
About viewing Instance Tempdb usage
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The following table describes the information displayed in the Tempdb usage view.
Table 5- 2 Instance Tembdb usage view
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| Temporary tables | Displays the following information on temporary tables:
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| Tempdb usage (Last second) | Displays statistical information on the tempdb database files within the last second. If the tempdb database contains more than one file, the displayed value is a total of all tempdb database files.
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| Tempdb size | Provides a graphical representation of the components of the tempdb database size, broken down as follows:
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About viewing Instance locks
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The following table presents a detailed explanation of the Lock Tree and Lock Breakdown (Last Minute) mechanism.
Table 5- 3 Instance Locks view
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| Lock tree | It is important to determine the following information for each blocking chain:
The Lock Tree provides the necessary information to get to the root of the problem by providing information on sessions currently involved in the blocking situation. A yellow lock indicates that the session is currently locking other sessions but is not itself blocked. A red lock indicates the session is currently blocked by another session. Note that a session may also block other sessions while being blocked by itself. To gain a better understanding of the lock tree take a closer look at its structure. Notice that the session located in the root of each chain is the session that blocks all others. Each session directly blocks all sessions positioned one level beneath it. The Lock Tree displays the SPID, program name, the object being blocked and the lock type. | ||
| Lock breakdown (Last minute) | Displays the Lock Wait duration broken down into lock levels such as Table, Page and Key, for the selected instance, during the last minute:
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See “About session states” on page 36See About session states.
About viewing Instance statistics
Displays instance statistics for the last 30 minutes, such as CPU usage, memory paging and disk usage. The following table describes the information displayed in the Instance statistics view.
Table 5- 4 Instance Statistics view
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| Sessions | Displays the number of sessions connected to the instance, broken down into active and locked sessions, as follows:
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| CPU usage | Displays statistics that report on CPU usage, broken down into SQL Server CPU usage and Non-SQL Server CPU usage. |
| Page faults | Displays statistics that report on page faults broken down into SQL Server Page Faults/sec and Non-SQL Server Page Faults/sec. |
| Load | Displays statistics that report on the instance load such as Batch Requests/sec, Transactions/sec and Logins/sec. |
| Disk operations | Displays statistics that report on I/O load, such as percentage of elapsed time the disks are busy servicing read/write requests. |
| Network packets | Displays statistics that report on network load, such as Max Packets Received/sec and Max Packets Sent/sec. |
About the Database entity
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The following table describes the information displayed in the Database Overview view.
Table 5- 5 Database Overview view
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| Session | Displays the following session-related information:
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| Statistics | Displays information on the following statistical parameters:
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| In MS-SQL (Last minute) | Displays the resource consumption breakdown of the database during the last minute (that is, 60 samples of the Collector). In addition to the resource distribution, the view displays the number of sessions in each state during the last sample. It is important to remember that since this view only displays the last minute's activities, you will always be viewing the activities that occurred during the last minute and not the activities that occurred since the last refresh action. The following information is displayed:
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See “About session states” on page 36See About session states.
About viewing Database locks
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Since the Lock tree represents the locks that are currently occurring, and the lock breakdown represents the duration of locks occurring during the last minute, it is possible that a situation may occur whereby a lock was freed, but since the last minute has not yet passed, the lock tree will display the message ‘No , "No locks found' " while the Lock Breakdown grid still shows lock duration. |
The following table provides a detailed explanation of the Lock Tree and Lock Breakdown (Last Minute) mechanism.
Table 5- 6 Database Locks view
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| Lock tree | It is important to determine the following information for each blocking chain:
The Lock Tree provides the necessary information to get to the root of the problem by providing information on sessions currently involved in the blocking situation. A yellow lock indicates that the session is currently locking other sessions but is not itself blocked. A red lock indicates the session is currently blocked by another session. Note that a session may also block other sessions while being blocked by itself. To gain a better understanding of the lock tree take a closer look at its structure. Notice that the session located in the root of each chain is the session that blocks all others. Each session directly blocks all sessions positioned one level beneath it. The Lock Tree displays the SPID, program name, the object being blocked and the lock type. | ||
| Lock breakdown (Last minute) | Displays the Lock Wait duration broken down into lock levels such as Table, Page and Key, for the selected database, during the last minute:
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See “About session states” on page 36See About session states.
About the Session entity
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The following table describes the information displayed in the session overview.
Table 5- 7 Session Overview
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| Session identifiers | Displays information on the session identifier's connection details, session-related statistics and a breakdown of session resource consumption, during the last minute.
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A connection includes session identifiers, such as, database, login, machine, user and work type, as reported by sysprocesses. |
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In ERP systems (if the appropriate ERP extension is installed), Precise for SQL Server replaces some identifiers as follows: In SAP: |
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Displays information on the following statistical parameters: |
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Displays the resource consumption breakdown of the session during the last minute (that is, 60 samples of the Collector). In addition to the resource distribution, the view displays the number of sessions in each state during the last sample. It is important to remember that since this view only displays the last minute's activities, you will always be viewing the activities that occurred during the last minute and not the activities that occurred since the last refresh action. The following information is displayed: |
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See About session states. |
The following table describes the information displayed in the Session Locks view.
Table 5- 8 Session Locks view
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View area Description
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| Locks | Displays lock wait duration broken down into lock levels such as Table, Page and Key, for the selected Session, during the last minute. The sessions that are currently involved in a locking or blocking situation with the selected session are displayed in tree format. Since the Lock tree represents the locks that are currently occurring, and the lock breakdown represents the duration of locks occurring during the last minute, it is possible that a situation may occur whereby a lock was freed, but since the last minute has not yet passed, the lock tree will display the message ‘No locks found' while the Lock Breakdown grid still shows lock duration. The Lock tree provides the necessary information to determine the following information for each blocking chain. A yellow lock indicates that the session is currently locking other sessions but is not itself blocked. A red lock indicates the session is currently blocked by another session. Note that a session may also block other sessions while being blocked by itself. To gain a better understanding of the lock tree take a closer look at its structure. Notice that the session located in the root of each chain is the session that blocks all others. Each session directly blocks all sessions positioned one level beneath it. The Lock Tree displays the SPID, program name, the object being blocked and the lock type. The Lock breakdown (Last minute) displays the Lock Wait duration broken down into lock levels such as Table, Page and Key, for the selected session, during the last minute: |
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The following table describes the information displayed in the Session Text view.
Table 5- 9 Session Text view
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| Text | Displays the text of the current statement. If the session is not active and executing a statement, a message notifying you that the session is not active and that no text is available is displayed. |
About the Locked Object entity
The Overview view in the Main area displays information on the objects that are currently locked (such as, Database, Object, Sessions, and Lock Type).
The following table describes the information displayed in the Locked Object overview view.
Table 5- 10 Locked Object Overview view
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| Displays the database containing the blocked object. |
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| Displays the object being blocked. |
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| Sessions | Displays the number of sessions that hold locks on the object or are blocked while trying to acquire a lock on the object. |
| Lock |
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| Type | Indicates the type of lock that is held against the object. |
You can display information on Locked Objects, in the Association area, when the selected entity is an instance or database. If an instance is selected, the Association area shows information on all currently locked objects in all the databases in the instance. If a database is selected, the table shows specific information on all currently locked objects in the selected database. Moving the cursor over the icon in the first column displays a ToolTip that identifies the object's lock type.
The following table describes the information displayed the Association area table.
Table 5- 11 Information displayed in Association area for Locked Objects
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| Indicates if there is a session waiting for the object. |
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| Object | Displays the object being blocked. |
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| Number of sessions that hold locks on the object or are blocked while trying to acquire a lock on the object. |
| Locks |
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| Total number of locks, broken down into the following lock types: Exclusive, Update, Shared, Intent Exclusive, Intent Update, and Intent Shared. |
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Indicates how many of the locks placed on the sessions were exclusive locks and shows a breakdown of the lock modes into lock levels, such as, Table, Row, Key, and Page. When exclusive locks are placed on a resource, the holding session is granted exclusive access to that resource and it can perform modification operations. |
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Indicates how many of the locks placed on the sessions were update locks and shows a breakdown of the lock modes into lock levels, such as, Table, Row, Key, and Page. Update locks are used to prevent deadlocks. A deadlock occurs when more than one session intends to update a resource and tries to lock the resource for future potential updates. The update lock is an interim stage which is promoted to an exclusive lock when the update is actually made. |
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| Shared | Indicates how many of the locks placed on the sessions were shared locks and shows a breakdown of the lock modes into lock levels, such as, Table, Row, Key, and Page. When there are shared locks on an object, concurrent transactions can read but not modify the resource. |
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| Exclusive | Indicates how many of the locks placed on the sessions were intent exclusive locks and shows a breakdown of the lock modes into lock levels, such as, Table, Row, Key, and Page. Indicates that a transaction intends to modify some subordinate resources in the lock hierarchy by placing exclusive locks on those particular resources. |
Table 5-11 Information displayed in Association area for Locked Objects
Column Description
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| Intent Update | Indicates how many of the locks placed on the sessions were intent update locks and shows a breakdown of the lock modes into lock levels, such as, Table, Row, Key, and Page. Indicates that a transaction intends to update some subordinate resources in the lock hierarchy, at a later stage, by placing update locks on those particular resources. |
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| Shared | Indicates how many of the locks placed on the sessions were intent shared locks and shows a breakdown of the lock modes into lock levels, such as, Table, Row, Key, and Page. Indicates that a transaction intends to read but not modify some subordinate resources in the lock hierarchy by placing shared locks on those particular resources. |
About the Session Holding Locks entity
The fact that a currently active session is holding a resource does not necessarily mean that there is a contention between resources. The Session Holding Locks entity displays information that lets you differentiate between sessions that are locking resources and sessions that are holding resources.
The following views display information on sessions holding locks:
- Overview
- Locks
- Text
About getting an overview of current sessions holding locks
Displays information on the session identifier, including connection details, session-related statistics and a breakdown of session resource consumption, during the last minute.
The following table describes the information displayed by the Session Holding Locks overview.
Table 5- 12 Sessions Holding Locks overview
View area Description
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| Session identifies | Displays the following information on the session's identifiers: |
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See SQL Server Books Online for more information.
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| Connection |
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A connection includes session identifiers, such as, database, login, machine, user and work type, as reported by sysprocesses. In ERP systems (if the appropriate ERP extension is installed), Precise for SQL Server replaces some identifiers as follows: In SAP: |
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| Statistics |
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Displays information on the following statistical parameters: |
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Displays the resource consumption breakdown of the session during the last minute (that is, 60 samples of the Collector). In addition to the resource distribution, the view displays the number of sessions in each state during the last sample. It is important to remember that since this view only displays the last minute's activities, you will always be viewing the activities that occurred during the last minute and not the activities that occurred since the last refresh action. The following information is displayed: |
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See About session states. |
About viewing information on the lock breakdown of a session that is holding locks
The Locks view displays lock wait duration broken down into lock levels such as Table, Page and Key, for the selected Session, during the last minute.
The sessions that are currently involved in a locking or blocking situation with the selected session are displayed in tree format. Since the Lock tree represents the locks that are currently occurring, and the lock breakdown represents the duration of locks occurring during the last minute, it is possible that a situation may occur whereby a lock was freed, but since the last minute has not yet passed, the lock tree will display the message ‘No , "No locks found' " while the Lock Breakdown grid still shows lock duration.
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The Lock Tree displays the SPID, program name, the object being blocked and the lock type. The following table describes the information displayed in this view.
Table 5- 13 Locks view for the Session Holding Locks entity
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| Lock tree | The Lock tree provides the necessary information to determine the following information for each blocking chain: |
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The Lock breakdown (Last minute) displays the Lock Wait duration broken down into lock levels such as Table, Page and Key, for the selected session, during the last minute: |
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About viewing the text of a session that is holding locks
Displays the text of the current statement. If the session is not active and executing a statement, a message notifying you that the session is not active and that no text is available is displayed.
About Statement and Batch entities
The Statement and Batch entities display information on a SQL statement that was executed by the selected session during the last time slice.
About getting an overview of current Statement and Batch entities
Displays general information on the statement or batch, including overall properties, its breakdown In MS-SQL during the last time slice, and the breakdown of the locks during the last time slice.
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The following table describes the information displayed in the Statement or Batch Overview view.
Table 5-1414 Statement or Batch Overview view
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| ID | Displays the internal statement hash value (SHV) calculated by the Collector, or, in the case of a stored procedure, displays the name of the stored procedure. |
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| Identifies the database on which the statement or batch is run. This information is used by Precise for SQL Server to display the statement's execution plan. |
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| Displays the parsing user who runs the statement or batch. This information is used by |
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| Precise for SQL Server to display the statement's execution plan. |
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| Number of times the Collector identifies that the statement or batch was executed. |
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| Total time required to execute the selected statement or batch during the last time slice. |
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| Average duration of each statement or batch execution during the last time slice. | |
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| Time | Cumulative CPU time for the statement or batch during the last time slice. |
| Physical I/O |
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| Operations | Total number of physical I/O requests during the execution of the statement or batch during the last time slice. |
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| Minimum number of threads used to execute the statement or batch in parallel. This counter is calculated from the ECID column in sysprocesses. This enables you to verify that SQL Server is using the best execution plan for the current statement. | |
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| Maximum number of threads used to execute the statement or batch in parallel. This counter is calculated from the ECID column in sysprocesses. This enables you to verify that SQL Server is using the best execution plan for the current statement. | |
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Displays the resource consumption breakdown of the statement or batch during the last minute (that is, 60 samples of the Collector). In addition to the resource distribution, the view displays the number of sessions in each state during the last sample. It is important to remember that since this view only displays the last minute's activities, you will always be viewing the activities that occurred during the last minute and not the activities that occurred since the last refresh action. The following information is displayed: |
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About viewing current Statement and Batch text
Displays text of the selected statement or batch.
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You can identify a performance problem by doing one or more of the following:
- Examining resource consumption of an entire instance and database
- Observing current session activity
- Examining a single connection
- Viewing ERP data
- Examining contentions
- Monitoring tempdb usage
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The Current tab provides an almost real-time picture of the performance and behavior of your SQL Server instance (or part of your instance). The Current tab displays information on the last time slice of activity, unless otherwise configured as for the last minute. Usually you will examine the activities of the entire instance level to determine what is happening in your system. By examining the current activity at an instance level of display, you can see how it is currently behaving and determine if there is an overall problem that affects all sessions or if there is a problem with specific sessions.
See “Examining contentions” on page 73.
. For more information, see Examining contentions.
To To examine resource consumption of an entire instance and database
- In the Instance list, choose the instance you want to analyze.
Do one of the following:- On the View controls in the Main area, click Overview. This will show you a breakdown of resource consumption for the last minute.
- On the View controls, click Statistics to analyze the current statistics of the selected instance.
- Launch to the Statistics tab, in-context, to view additional statistical information on the selected instance.
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The Association area of the Current tab lets you view which sessions are currently connected to the Instance, or which sessions are currently using a specific database or holding a specific object. You can observe the current state of the session and determine if it is active or waiting for a resource. You can also identify the session by different identifiers such as its login information, the machine it is running on, or the programs it is running. The currently active TSQL code is displayed for active sessions.
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- In the Instance list, choose the instance you want to analyze.
- On the Association controls in the Association area, select one of the following to focus your investigation on the sessions that were active in SQL Server during the last minute:
- Active Sessions
- Sessions
- Sessions Holding Locks
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You may need to explore a single running SPID, to obtain more information on it. In the Association area you can drill down to the specific SPID in question, and continue your analysis.
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- In the Instance list, choose the instance you want to analyze.
- In the Association area, drill down to the session whose connection you want to analyze.
- Continue your analysis by examining its resource breakdown, its recent statements, or the batches in which the session was executed, during the last few minutes.
- On the View controls, click Locks and observe which locks the session is holding or waiting for.
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Certain obstacles make it difficult to investigate ERP sessions. Most activity is registered in SQL Server under generic names. For example, in PeopleSoft®, all PeopleSoft activities are listed under a single login (sa) and generic program names (PeopleSoft).
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- Verify that the Precise for SQL Server Interpoint extension is installed. For more information, see the Precise Installation Guidesee Installation and Administration.
- In the Instance list, choose the instance you want to analyze. For this example, you are viewing Siebel session data.
- In the Association area, view Siebel session data for each session in the selected instance and observe to which SQL Server session it is correlated to.
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One of the common uses of the Current tab is to solve contentions. A contention is a situation in which a session waits for a resource held by another session. In a busy application, there can be situations in which one session locks many other sessions that are waiting for the resource. For example, every time a user logs on to the system the Logon table is updated. If the system is not properly tuned a situation could arise where while the Logon table is being held by another session no user could log in into the system. This type of scenario can be resolved very easily using Precise for SQL Server. You can observe all the locks on the instance, in the Locks view of the Instance entity.
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- In the Instance list, choose the instance you want to analyze.
- On the View controls in the Main area, click Locks and examine the locking contentions.
- Check which sessions and programs are holding the locks and locate which objects are involved in contentions.
- In the Association area, on the Locks tab, observe the status of the locking session and the type of lock (for example, table lock or page lock). See “Examining Examining locking over time of a database entity” on page 101.entity.
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To be able to avoid a blocking situation, it is important to have an accurate picture of all the locks held in the system. This will help you understand if the lock system is tuned and if it is possible to avoid a potential blocking situation. Using Precise for SQL Server, you can now observe the locks currently held in the Instance and group them according to lock level and lock mode.
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- In the Instance list, choose the item you want to analyze.
- On the View controls in the Main area, click Locks and examine the locking contentions. Move the cursor over the locked session in the tree to display the text of the locked session.
- On the Association controls, in the Association area, click Locked Objects, and examine the locks in SQL Server. Identify which objects have many locks held on them, which objects are in use, and how they are being held.
- Examine all the locks in the instance shows which objects are in use (there is a lock on the object) and how they being held. As you can see the table is involved in a contention with other sessions.
- If you find an object that is locked, examine the sessions that are holding locks on the object by drilling down to the object.
- On the View controls in the Main area, click Overview and view the lock type.
- After drilling down to the object, on the Association controls in the Association area, click Sessions to find the sessions that hold locks on the object.
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Exploring Tempdb usage is very important during the tuning and monitoring process. Even a well-tuned application can suddenly suffer from a degradation in response time, due to a session that was busy with the Tempdb database. It is therefore important to monitor Tempdb performance.
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- In the Instance list, choose the instance you want to analyze.
- On the View controls in the Main area, click Tempdb Usage and analyze Tempdb performance.
Precise. Performance intelligence from click to storage. Learn more > >
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