Diagnostic tracing is an advanced method of application profiling. The diagnostic tracing data produced by the database server can include the timestamps and connection IDs of statements handled by the database server. For queries, diagnostic tracing data includes the isolation level, number of rows fetched, cursor type, and query execution plan. For INSERT, UPDATE, and DELETE statements, the number of rows affected is also included. You can also use diagnostic tracing to record information about locking and deadlocks, and to capture performance statistics.
You can use the data gathered during diagnostic tracing to perform in-depth application profiling activities, such as identifying and troubleshooting:
Specific performance problems
Statements that are unusually slow to execute
Improper option settings
Circumstances that cause the optimizer to pick a sub-optimal plan
Contention for resources (CPUs, memory, disk I/O)
Application logic problems
Tracing data is also used by tools, such as the Index Consultant, to make specific recommendations on how to change your database or application to improve performance.
The tracing architecture is robust and scalable. It can record all the information that request logging records, as well as details to support tailored analysis.
Application Profiling does not capture an event, but captures long-running statements within the event. To capture an event, embed the event code within a procedure and call the procedure from the event. Before running the procedure, turn on tracing with a custom level that specifies low detail with no conditions on statement capture. When the tracing session is finished, turn off Application Profiling.
Trace session data
Diagnostic tracing configuration
Diagnostic tracing levels
Diagnostic tracing scopes
Customized diagnostic tracing levels
Diagnostic tracing types
Diagnostic tracing conditions
Determining current diagnostic tracing settings (Sybase Central)
Determining current diagnostic tracing settings (SQL)
Diagnostic tracing configuration settings
Changing diagnostic tracing settings during a tracing session
Creating a diagnostic tracing session (Sybase Central)
Creating a diagnostic tracing session (SQL)
Analysis of diagnostic tracing information
Troubleshooting performance problems
When hardware resources are a limiting factor
Tools for debugging application logic
Performing request trace analysis
Creating an external tracing database (Sybase Central)
Creating an external tracing database (command line)
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