This section includes the following topics:
- About the Current tab
- How the Current tab is structured
- About the entities you can examine in the Current tab
- How the Current tab can help you identify performance problems
About the Current tab
The Current tab displays near real-time information on all sessions that were connected to your Sybase database during the last minute. If you have recognized an immediate performance issue and are looking for an indication as to where to begin your analysis, start with the Current tab. It is also worthwhile to start with the Current tab if your system appears to hang and there is no throughput.
You can use this tab to monitor your system's current activities and resource consumption and to identify performance problems, such as current locking problems and sessions involved in locks, as they occur.
The Current tab provides answers to the following types of questions: "How many sessions are currently running?" or "Why doesn't my application work when I click OK?" The Current tab also shows you which sessions are currently active, and which machines are connected to which users.
Using the Current tab, you can monitor current connections to your Sybase instance, check the state of each connection, and identify the resources currently utilized by each session. Further investigation of each session provides a thorough understanding of the SQL statement being executed, the login name executing the statement, the program, and the resource utilization for the session. In addition, you can view the statements and batches executed by the selected session within the last time slice.
In the Current tab, data on a current session is continuously updated to provide information on what happened during the last minute or time slice. Because the displayed session information is derived from a dynamic application, it is recommended to regularly refresh the screen, either manually or automatically, to ensure that the information displayed is up-to-date.
The Current tab displays information on the last minute of activity. For example, if you have 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.
How the Current tab is structured
The Current tab displays information on a selected entity and its associated entities. For example, if the parent entity is a Session, its associated entities would be Statements or Batches.
When you open the Current tab from the Dashboard tab, the selected entity is by default Instance, meaning that information is displayed on the instance level. When you open the Current tab from the Activity tab, the tab is launched with the selected instance or entity (in the case of an entity, this is only valid for the database entity), meaning that the information is displayed on the instance or entity level. If you open the Current tab from another tab, the historical settings (meaning those settings which were selected when you left the tab, such as a drill-down to a Locked Objects entity) are taken into account and the information displayed the last time you viewed this tab is displayed (similar to clicking the History button and returning to a previous tab).
The selected entity is always reflected in the Tab heading, which serves as a point of orientation. The highest-level entity you can view information for in the Current tab is Instance. You can view another instance by selecting it from the Instance list.
About the Main area in the Current tab
The Main area shows comprehensive information on the selected entity, such as the In Sybase data for the last minute, and the number of active sessions.
About the Association area in the Current tab
The Association area provides corresponding information on the entities associated with the selected entity (displayed in the Main area). For example, you can associate to the Active Sessions related to the selected instance. The selection you make is reflected in the Association area only; the Main area remains unchanged. For some entities, tabs above the Association area enable you to view additional information. For example, the tabs displayed for a database are: General, In Sybase and Statistics. Clicking a tab displays different table columns with the same type of child entities.
From the Association area, you can also drill down to another entity by clicking a table row. A drilldown affects the entire tab. When you drill down to another entity, the Tab heading displays the new selection, the Main area displays information on the newly selected entity, and the Association area displays the entities associated with the selected entity.
For example, when you want to view information on a specific session, in the Current tab, choose Sessions from the Association controls. The Association area changes to display sessions-related information. Note that the Tab heading and the Main area remain unchanged.
In the Association area, click the row of the session that you want to view detailed information for. The Tab heading indicates the newly selected entity; the Main area displays detailed information on the session you drilled down to, and the Association area shows information on the statements associated with this session.
See About Precise for Sybase tabs and About the Dashboard tab.
About the entities you can examine in the Current tab
The Current tab displays information on different entities. This section provides an overview of all entities, their meaning, and their views.
The following entities can be examined in the Current tab:
- Instance entities
- Database entities
- Session entities
- Statement and Batch entities
About the Instance entity
The Instance entity displays information on the resource consumption of the entire instance and allows you to focus on how it is performing, during the last minute.
About getting an overview of current Instance entities
The Overview displays information on the activity of the instance, such as number of sessions and the resource consumption breakdown of the instance.
The table below describes the information displayed in the Instance overview.
Table 1 Instance overview
| View Area | Description |
|---|---|
| Sessions | Displays the following session-related information:
|
| Statistics | Displays information on the following statistical parameters:
|
| In Sybase (Last Minute) | Displays the resource consumption breakdown of the instance during the last minute (that is, 60 samples of the Collector agent). 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 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:
All the information displayed in this table represents information collected during the last minute, with the exception of the Sessions column, which represents the number of sessions, in the last sample, that were in a particular state. |
See About session states.
About the Database entity
The Database entity displays information on the activity and resource consumption of the database, including the number of sessions connected to the database during the last sample taken, various session-related statistics and the database resource consumption breakdown for the last minute.
About getting an overview of current database activities
The Overview displays information on the activity and resource consumption of the database, including the number of sessions connected to the database during the last sample taken, various session-related statistics and the database resource consumption breakdown for the last minute.
The table below describes the information displayed in the Database overview.
Table 2 Database entity overview
| View Area | Description |
|---|---|
| Session | Displays the following session-related information:
|
| Statistics | Displays information on the following statistical parameters:
|
| In Sybase (Last Minute) | Displays the resource consumption breakdown of the database during the last minute (that is, 60 samples of the Collector agent). 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:
All the information displayed in this table represents information collected during the last minute, with the exception of the Sessions column, which represents the number of sessions in the last sample that were in a particular state. |
See About session states.
About the Session entity
The Session entity displays information on a single connection with Sybase. Precise for Sybase identifies a session by the following attributes:
- System Process ID (SPID). A unique integer assigned to each user connection when the connection is made.
- Host Process (PID)
When one of these attributes changes, a new session is recorded and displayed.
About getting an overview of a session entity
The Overview displays information on the session identifier's connection details, session-related statistics and a breakdown of session resource consumption, during the last minute.
The table below describes the information displayed in the Session overview.
Table 3 Session overview
| View Area | Description |
|---|---|
| Session Tab | Displays information on the following session identifiers:
|
| Connection Tab | A connection includes session identifiers, such as database, login, machine and user, as reported by the sysprocesses.The following information is displayed:
|
| In Sybase (Last Minute) | Displays the resource consumption breakdown of the session during the last minute (that is, 60 samples of the Collector agent). 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:
|
| Locks Tab | Displays information on the current session locks that exists in the instance. Contains the following information on each session:
|
| Statistics Tab | Displays information on the following statistical parameters:
|
See About session states.
About viewing the current statement's text
The Text view 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 statement properties, the breakdown of the statement In Sybase during the last time slice, and some statistics regarding the resource consumption of the statement.
When the selected entity is a Batch, the information area displays the entire text of the improvised batch or stored procedure. When the selected entity is a Statement, the information area only displays the part of the batch text that forms the statement.
The table below describes the information displayed in the Statement or Batch overview.
Table 4 Statement or Batch overview
| Parameter | Description |
|---|---|
| Statement/Batch ID | Internal statement hash value (SHV) calculated by the Collector agent. |
| Database | Identifies the database on which the statement or batch is run. This information is used by Precise for Sybase to display the statement's execution plan. |
| User | Displays the parsing user who runs the statement or batch. This information is used by Precise for Sybase to display the statement's execution plan. |
| Executions | Number of times the Collector agent identifies that the statement or batch was executed. |
| Duration | Total time required to execute the selected statement or batch during the last time slice. |
| Duration (Avg) | Average duration of each statement execution during the last time slice. |
| CPU Time | Cumulative CPU time for the statement during the last time slice. |
| Physical I/O Operations | Total number of physical I/O requests during the execution of the statement or batch during the last time slice. |
| Parallel Sessions (Min) | Minimum number of threads used to execute the statement or batch in parallel. This counter is calculated from the fid column in sysprocesses. This enables you to verify that Sybase is using the best execution plan for the current statement. |
| Parallel Sessions (Max) | Maximum number of threads used to execute the statement or batch in parallel. This counter is calculated from the fid column in sysprocesses. This enables you to verify that Sybase is using the best execution plan for the current statement. |
| In Sybase (Last minute) | Displays the resource consumption breakdown of the statement or batch during the last minute (that is, 60 samples of the Collector agent). 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:
|
See How information is collected.
About viewing current Statement or Batch text
Displays text of the selected statement or batch.
About the Statement and Batch Association area
It is possible to view statement or batches in the Association area while drilling down from a single session. The table includes only statements or batches that were executed during the last time frame. A time frame is a 15-minute interval. If a statement or batch was executed in an earlier time frame, this statement or batch no longer appears in the Current tab. Instead, you can view information on this statement or batch in the Activity tab.
The table below describes the information displayed in the Association area, when viewing a statement or batch entity.
Table 5 Statement/Batch Association table
| Association Tab | Function |
|---|---|
| General | Shows general information on the displayed statements or batches. |
| In Sybase | Shows information on performance and statistics of the displayed statements or batches. |
| Statistics | Shows statistics of the displayed statements or batches. |
See About session states, Understanding In Sybase session states, and Understanding Non-In Sybase session states.
How the Current tab can help you identify performance problems
You can identify a performance problem by doing one or more of the following actions.
Examining the resource consumption of an entire instance and database
The Current tab provides an almost real-time picture of the performance and behavior of your Sybase instance. It displays information on the last minute of activity.
To examine the resource consumption of an entire instance and database
- Examine the activities of the entire instance level to determine what is happening in your system.
- Examine the current activity at an instance level of display to see how the system is currently behaving and determine if there is an overall problem that affects all sessions or if there is a problem with specific sessions.
- Start your investigation in the Overview view of an Instance or Database entity. This will show you a breakdown of resource consumption for the last minute.
Observing session activity
In the Association area you can see which sessions are currently connected to the Instance, or view which sessions are currently using a specific database or holding a specific object.
To observe session activity
- Observe the current state of the session and determine if it is active or waiting for a resource.
- Identify the session by different identifiers such as its login, the machine it is running on, or the programs it is running. The current active SQL code is displayed for active sessions.
- If you have hundreds of sessions running, and you want to focus your investigation on the sessions that were active in Sybase during the last minute, select Active Sessions from the Association Controls in the Association area.
Examining a single connection
You may need to explore a single running SPID, to obtain more information for it. To examine a single connection
- Drill down to the specific SPID in question. Continue examining its resource breakdown, its recent statements, or the batches in which the session was executed, during the last few minutes.
- Check if the session is blocked and by whom.