Tracing Oracle Database PLSQL using DBMS_HPROF and PLSQL Profiler

 

There may be times when a normal SQL trace of a PLSQL package is not sufficient. For example, when the SQL statements seem to be running fast, but the procedure takes a long time. It may be useful to understand which calls in the PLSQL package are taking the time. With this in mind, this document provides a step by step guide to tracing PLSQL using DBMS_HPROF.

If we are writing Procedure ,  its always advice able to  add below in procedure to capture more details on error 

DBMS_UTILITY.FORMAT_ERROR_BACKTRACE holds the line number of the error.

DBMS_UTILITY.FORMAT_ERROR_STACK still holds the last error message.

One of way to debug  compilation issues is using  PLSQL_DEBUG = true; before complication

EG 

alter session set plsql_warnings='enable:all';

ALTER SESSION SET PLSQL_WARNINGS='ENABLE:ALL','DISABLE:06015';

ALTER SESSION SET PLSQL_DEBUG = true;

ALTER PACKAGE XXXX COMPILE DEBUG;

ALTER PACKAGE XXXX COMPILE DEBUG BODY;

Tracing Plsql using Event 10938

One of  other way   to trace plslq is using   trace event 10938  .

Event 10928 - Trace PL/SQL Execution  :  This event traces PL/SQL execution

ALTER SESSION SET EVENTS '10928 trace name context forever, level 1';

Event 10938 - Dump PL/SQL Execution Statistics  : This event dumps PL/SQL execution statistics.

ALTER SESSION SET EVENTS '10938 trace name context forever, level 1';

Level    Description for event 10938

1 Trace all calls 

2 Trace calls to enabled programs only 

4 Trace all exceptions 

8 Trace exceptions in enabled program units only 

10 Tracing for levels 2 and 8

14 Tracing for levels 2, 4, and 8

There is also option for tracing  plsql  using dbms_trace.set_plsql_trace

dbms_trace.set_plsql_trace(dbms_trace.TRACE_ENABLED_CALLS+dbms_trace.TRACE_LIMIT);

DBMS_HPROF.

create directory PROF_DIR as '/home/oracle/pl';

grant all on directory plshprof_dir to pltest;

grant execute on dbms_hprof to pltest;

-- as user PLTEST 

execute dbms_hprof.create_tables();

With the last call the tables DBMSHP_TRACE_DATA, DBMSHP_RUNS, DBMSHP_FUNCTION_INFO and DBMSHP_PARENT_CHILD_INFO are created. They store the information in the database schema  and can be queried afterwards. 

Create the DBMS_HRPOF objects if not present .

Log on to the PLTEST  that owns the PLSQL package being profiled.

sqlplus <user>/<password>

SQL> @$ORACLE_HOME/rdbms/admin/dbmshptab.sql

Profiling Pl/sql 

SET SERVEROUTPUT ON;

EXEC DBMS_HPROF.START_PROFILING('PROF_DIR','P1_PROFILE_DATA.trc');

/* Within the same session run the P1 procedure */

EXEC P1;

/* Stop the profiling */

EXEC DBMS_HPROF.STOP_PROFILING;

Analyzing Raw File Generated : 

This raw profiler trace file can be analyzed in two ways:

1) Using the DBMS_HPROF.ANALYZE function.

2) Using the "plshprof" command line utility. 

Eg :

plshprof -output <out_file_name> P1_PROFILE_DATA.trc

Reference : 

How to Tune PL/SQL Applications and Identify Hot Spots using DBMS_HPROF (Doc ID 763944.1)

How to resolve error - PLS-00201: identifier 'DBMS_HPROF' must be declared? (Doc ID 2867790.1)

SRDC - Providing Supporting Information for PL/SQL Runtime Issues (Doc ID 2288591.1)

https://blogs.oracle.com/coretec/post/plsql-tuning-with-plsql-hierarchical-profiler

DBMS_PROFILER

 What about customers who have only limited privileges to their Oracle environment and who may not have access to a logical directory. The solution is the usage of the package DBMS_PROFILER, which writes the data directly into database tables. The procedure works similar to the described procedure of DBMS_HPROF.

First the corresponding repository tables PLSQL_PROFILER_RUNS, PLSQL_PROFILER_DATA and PLSQL_PROFILER_UNITS are created in the application schema. To do this, use the proftab.sql utility from the $ORACLE_HOME/rdbms/admin directory.

Configuring the profiler is fairly easy; in the schema that owns the PL/SQL objects the proftab.sql script (located at $ORACLE_HOME/rdbms/admin) 

must be run to create the tables that the profiler needs to store run data; those tables are:

PLSQL_PROFILER_UNITS

PLSQL_PROFILER_RUNS

PLSQL_PROFILER_DATA

An example of how to use the profiler once the setup has been successfully completed follows:

set linesize 1000 trimspool on

select dbms_profiler.start_profiler('DATES PACKAGE') from dual;

select dates_pkg.minutes_elapsed(sysdate-10, sysdate) from dual;

select dbms_profiler.stop_profiler from dual;

spool dates_package_profiler_run.rpt

@?/rdbms/admin/profsum

spool off

or 

execute dbms_profiler.start_profiler;

execute testprof;

execute dbms_profiler.stop_profiler;

select runid, run_date, run_comment from plsql_profiler_runs;  

Reference : 

https://docs.oracle.com/cd/E11882_01/appdev.112/e41502/adfns_profiler.htm#ADFNS02301

Script to produce HTML report with top consumers out of PL/SQL Profiler DBMS_PROFILER data (Doc ID 243755.1)

https://oracle-base.com/articles/11g/plsql-hierarchical-profiler-11gr1