Oracle sysresv utility to release shared memory / semaphores -- No need for ipcs and ipcrm

After shutdown of Oracle database , shared memory segments staying behind is known issues   in Linux .  Ideally Dba use Ipcs and Ipcrm  to release  shared  memory segments .

Also there is less known Linux utility pmap 

Eg :  [oracle]$ pmap `pgrep -f lgwr`

There is  Oracle utility sysresv  that can  be used to release shared memory segments and there is no need  to use Ipcs and Ipcrm .  

Eg :  sysresv -l instance1 

 

Usage:

------

sysresv: 

usage   : sysresv [-if] [-d <on/off>] [-l sid1 <sid2> ...]

          -i : Prompt before removing ipc resources for each sid

          -f : Remove ipc resources silently, oevrrides -i option

          -d <on/off> : List ipc resources for each sid if on

          -l sid1 <sid2> .. : apply sysresv to each sid

Default : sysresv -d on -l $ORACLE_SID

Note    : ipc resources are attempted to be deleted for a

          sid only if there is no currently running instance

          with that sid. 

   
Examples:
---------

o  Instance is not running:

   /u02/app/oracle/product/8.1.7> sysresv

   IPC Resources for ORACLE_SID "R817" :
   Shared Memory
   ID              KEY
   No shared memory segments used
   Semaphores:
   ID              KEY
   No semaphore resources used
   Oracle Instance not alive for sid "R817" 


o  Instance is running:

   /u03/app/oracle/product/8.1.6> sysresv

   IPC Resources for ORACLE_SID "ORCL" :
   Shared Memory:
   ID              KEY
   16437           0xe4efa8dc
   Semaphores:
   ID              KEY
   12320802        0x09d48346
   Oracle Instance alive for sid "ORCL"


o  Attempting to remove memory and semphores using sysresv when Oracle 
   detects an instance is running:

   /u03/app/oracle/product/8.1.6> sysresv -f

   IPC Resources for ORACLE_SID "ORCL" :
   Shared Memory:
   ID              KEY
   16437           0xe4efa8dc
   Semaphores:
   ID              KEY
   12320802        0x09d48346
   Oracle Instance alive for sid "ORCL"
   SYSRESV-005: Warning
           Instance maybe alive - aborting remove for sid "ORCL" 


o  Removing IPC resources:

   [Sysresv shows memory and semaphores exist but Oracle determines the 
    instance is not alive.  Cleanup is needed.]

   /u03/app/oracle/product/8.1.6> sysresv

   IPC Resources for ORACLE_SID "ORCL" :
   Shared Memory:
   ID              KEY
   16837           0xe4efa8dc
   Semaphores:
   ID              KEY
   12714018        0x09d48346
   Oracle Instance not alive for sid "ORCL" 
 

o  Removing IPC resources using sysresv:

   /u03/app/oracle/product/8.1.6> sysresv -i

   IPC Resources for ORACLE_SID "ORCL" :
   Shared Memory
   ID              KEY
   No shared memory segments used
   Semaphores:
   ID              KEY
   No semaphore resources used
   Oracle Instance not alive for sid "ORCL"
   Remove ipc resources for sid "ORCL" (y/n)?y
   Done removing ipc resources for sid "ORCL"
   /u03/app/oracle/product/8.1.6


   Verify the resources were removed:

   /u03/app/oracle/product/8.1.6> sysresv

   IPC Resources for ORACLE_SID "ORCL" :
   Shared Memory
   ID              KEY
   No shared memory segments used
   Semaphores:
   ID              KEY
   No semaphore resources used
   Oracle Instance not alive for sid "ORCL"  

     
o  If you need to remove memory segments, and Oracle detects the
   instance is alive through sysresv:

   % ipcrm -m <memid>

   Where <memid> is the memory id shown in the sysresv output.

   Example:
   % ipcrm -m 16437

   If you need to remove semaphores, and Oracle detects the
   instance is alive through sysresv:

   % ipcrm -s <semid>

   where <semid> is the semaphore id shown in the sysresv output.

   Example:
   % ipcrm -s 12320802

Reference :

SYSRESV Utility (Doc ID 123322.1)

Startup fail with ORA-29701 & ORA-29702 after the DB crash. (Doc ID 2160481.1)

Oracle Solaris Zone management

Solaris Zones is a software partitioning technology, which provides a means of virtualizing operating system services to create an isolated environment for running applications. 

This isolation prevents processes that are running in one zone from monitoring or affecting processes running in other zones

After installing Oracle Solaris 10 on a system, but before creating any zones, all processes run in the global zone. 

After you create a zone, it has processes that are associated with that zone and no other zone. 

Any process created by a process in a non-global zone is also associated with that non-global zone. Any zone which is not the global zone is called a non-global zone.

File and Directory : 

As a  Oracle Dba script to start database as part of cluster are placed under  /etc/rc0.d/.  Eg  /etc/rc0.d/K10dbora 

1) 

The directory /etc/zones contains the configuration files for each zone by the zone name. Examining these files will show the show the configuration of the zones.

The index file in this directory also contains the status of the zones:

# cat <zonename>.xml

cat /etc/zones/myzone.xml

Viewing Global Zone name from Local Zone :

Global-Zone# cat globalzonename.sh

#!/usr/bin/bash

for i in `/usr/sbin/zoneadm list -v | /usr/bin/egrep -v "ID|global" |/usr/bin/awk ' { print $4 } '`; do echo `uname -n` > $i/root/etc/GLOBALZ; done

Commands : 

1) 

# /usr/sbin/zoneadm list -vi to show status of all installed zones (i-stands for installed)

# /usr/sbin/zoneadm list -vc to show status of all configured zones (c-stands for configured which includes installed zones).

2) 

zonecfg -z zonename info    -->  To list resources used by each zones : Use zonecfg -z with the info option to list a specific zone configuration.

3) 

zonename

4) 

zpool list

5) 

zonestat -z zonename -r physical-memory 2

zonestat -z zone1,zone2 5 

Oracle Database SQLTXPLAIN (SQLT) Installation and report generation

 

There are  lot of documents online sqlt however  i have documented below for my quick reference and if it helps someone 

Sqlt Needs  installation which  becomes challenge sometimes , in that case lighter version sqlhc can be used  

Installation : 

Install SQLT

Install SQL by executing the installation script sqlt/install/sqcreate.sql connected as SYS:

# cd sqlt/install

# sqlplus / as sysdba

SQL> START sqcreate.sql

During the installation you will be asked to enter values for these parameters:

Optional Connect Identifier - In some restricted-access systems you may need to specify a connect identifier like @PROD. If a connect identifier is not needed, enter nothing and just hit the "Enter" key.

SQLTXPLAIN password - Case sensitive in most systems.

SQLTXPLAIN Default Tablespace - Select from a list of available permanent tablespaces which one should be used by SQLTXPLAIN for the SQLT repository. It must have more than 50MB of free space.

SQLTXPLAIN Temporary Tablespace - Select from a list of available temporary tablespaces which one should be used by SQLTXPLAIN for volatile operations and objects.

Optional Application User - This is the user that issued the SQL statement to be analyzed. For example, if this were an EBS system specify APPS, on Siebel you would specify SIEBEL and on People Soft 

SYSADM. You won't be asked to enter the password for this user. You can add additional SQLT users after the tool is installed, by granting them role SQLT_USER_ROLE or by using provided script sqlt/install/sqguser.sql

Licensed Oracle Pack. (T, D or N) - You can specify T for Oracle Tuning, D for Oracle Diagnostic or N for none. If T or D is selected, SQLT may include licensed content within the diagnostics files it produces. Default is T. If N is selected, SQLT installs with limited functionality.

Report Generation : 

Note  :  after 19c migration  sqltadmin object becomes invalid and  sqlt has to be reinstalled as per doc id 2920902.1 

== EXTRACT SQLT reports:

Starting with 12cR1, SQLT can be executed under SYS user -- for so, do as follows before starting execution:

Fix for :  ORA-06598   - inherit any  and  sqlt role 

SQL> CONN /as sysdba

SQL> GRANT INHERIT PRIVILEGES ON USER sys TO sqltxadmin;

1: To speedup SQLT Extraction -- connect as SQLTXADMIN user and run:

EXEC sqltxplain.sqlt$a.set_param('sta_time_limit_secs', '30');

EXEC sqltxplain.sqlt$a.set_sess_param('sql_tuning_advisor','N');

EXEC sqltxadmin.sqlt$a.set_param('ash_reports', '0');

EXEC sqltxadmin.sqlt$a.set_param('awr_reports', '0');

-- sqltxtract.sql script gather the details from memory or else from AWR snapshots.

cd sqlt/run

sqlplus ep/ep; -- connect as application user

@sqltxtract.sql sqlid sqltpassword

@/home/oracle/sqlt/run/sqltxtract.sql jkz7v96ym42c6 SQLTXPLAIN

 

Reference : 

How to Collect Standard Diagnostic Information Using SQLT for SQL Issues (Doc ID 1683772.1)

Document 215187.1 SQLT Diagnostic Tool

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

Oracle Rac Node failover Testing

     As part of new build we need to  do  node failover testing hence documenting some steps  known to me 

Objective	Action	Expectations
To test accidental change of  IP addresses of the cluster	Modify etc/hosts and change theVIP addresses - Try starting thecluster	The cluster must not be able to bootup with error messages related to network Ips.
To test the failure of ASM instance  (ASM Instancecrash)	On Node 1, kill the processes  related to ASM	The cluster must not be affected by ASM crash on node 1
To test the failover of the network  card of the public IPaddress.	Plug out one of the cableconnecting  the node to thepublic network	The ping from the client  should beable to go thru
To test the stability of the db by killing  a ora server process	kill off a process related to the oracle daemons from a terminal.This should crash the database processes.	The sql session should not be affected and failover to the next node without any disruption
To test thecomplete failover of the session in event of a node(e.g. sudden shutdown	1. Connect from the client to the database via sqlplus. 2. power off the unix box inwhich the sqlplus connection isat.	The sql session should not be  affected and failover to the nextnode without any disruption
To test the failover session of a connected oracleuser in the event of an instance failureTo test the failoversession of aconnected oracleuser in the event of an instance failure	1. Connect from a client to node1 in the RAC Environment usingsqlplus. 2. Connect to the database onnode 1 and do a shutdown. sqlplus / as sysdba	The sql connection should be able to swing over to other instance and stillcontinue the select query # – sqlplus connection from client todb is still available
To test Crash of Grid  Processes	Kill Lmon process on rac node	They must be restarted  automatically
To  Test for automatically shifting of  scan listeners	Reboot Node 1 using  the OS reboot command	1. When noe 1 goes down all scan listeners must shift to remaining node 2. When node 1 comes up  scan listeners must again shift back to original node
To test storage  crash	Forcibly make scan disk unvisible to both nodes	The cluster must go down and should not start since rac does not safeguard to storage failures
TAF failoer test	to test sql and session   failover

 

Oracle Database Performance Hub report using DBMS_PERF

  When we  have performance issues normally we have to login to  oem  to get  performance details . 

  We can get quick snap of  performance using DBMS_PERF.REPORT_PERFHUB    as mentioned below .   Its old tool  introduced in 12c but  not frequently used . 

Command : 

SET  LONG   10000000 ;

 SET LONGC 10000000 ;

 SET LINESIZE 32767 ;

 SET PAGESIZE 0 ;

 SET TRIMSPOOL ON ;

SPOOL perfhub.html

SELECT DBMS_PERF.REPORT_PERFHUB FROM DUAL;

SPOOL OFF;

.Other option used :

SET HEADING OFF LINESIZE 32767 PAGESIZE 0 TRIMSPOOL ON TRIMOUT ON LONG 9999999 VERIFY OFF LONGCHUNKSIZE 100000 FEEDBACK OFF

SET TERMOUT OFF

spool perfhub.html

SELECT DBMS_PERF.REPORT_PERFHUB (

    is_realtime         => 0           -- (  0 = dba_hist, 1 = v$ash  )

  , outer_start_time    => sysdate-1

  , outer_end_time      => sysdate

  , selected_start_time => TIMESTAMP'2023-05-15 20:15:00'

  , selected_end_time   => TIMESTAMP'2023-05-15 20:45:00'

  , type=>'ACTIVE'

)

FROM dual ;

spool off

SET TERMOUT ON HEADING ON PAGESIZE 5000 LINESIZE 999 FEEDBACK ON 

 

Historical SQL monitoring report can be extracted for particular SQL statement using SQL Details report.

Example: To generate SQL details report to get the SQL monitoring information for particular SQL statement in historical mode.

SQL> set pages 0 linesize 32767 trimspool on trim on long 1000000 longchunksize 10000000

SQL> spool sql_details_history.html

SQL> select dbms_perf.report_sql(sql_id=>'9vkyyg1xj6fgc',is_realtime=>0,type=>'active',selected_start_time=>to_date('10-SEP-18 04:00:00','dd-MON-YY hh24:mi:ss'),selected_end_time=>to_date('10-SEP-18 05:00:00','dd-MON-YY hh24:mi:ss')) from dual;

SQL> spool off

Note in 19c or higher it is better to add "outer_start_time" and  "outer_end_time" to get the desired results:

SQL> set pages 0 linesize 32767 trimspool on trim on long 1000000 longchunksize 10000000

SQL> spool sql_details_history.html

SQL> select dbms_perf.report_perfhub( is_realtime=>0, outer_start_time=>to_date('06-SEP-2022 12:00:00','dd-MON-YYYY hh24:mi:ss'), outer_end_time=>to_date('06-SEP-2022 13:00:00','dd-MON-YYYY hh24:mi:ss'), selected_start_time=>to_date('06-SEP-2022 12:00:00','dd-MON-YYYY hh24:mi:ss'), selected_end_time=>to_date('06-SEP-2022 13:00:00','dd-MON-YYYY hh24:mi:ss')) from dual;

SQL> spool off

We can also   generate   historical sql  monitoring report  using dbms_auto_report 

==>  Getting Details 

SQL> select distinct COMPONENT_NAME from DBA_HIST_REPORTS;

COMPONENT_NAME

-----------------------------------------------------------

sqlmonitor

perf

COL SQL_EXEC_START for a25

col sql_exec_id form a20

col  sql_id for a20

select key1 as sql_id ,  to_char( key2) as sql_exec_id ,   

to_char( to_date (key3 , 'mm:dd:yyyy hh24:mi:ss')  , 'yyyy-mm-dd hh24:mi:ss' ) sql_exec_start , 

report_id , instance_number , session_id , session_serial# , period_start_time , period_end_time 

from dba_hist_reports where key1='&sql_id'  order by sql_exec_start ;

SELECT report_id,

       EXTRACTVALUE(XMLType(report_summary),'/report_repository_summary/sql/@sql_id') sql_id,

       EXTRACTVALUE(XMLType(report_summary),'/report_repository_summary/sql/@sql_exec_id') sql_exec_id,

       EXTRACTVALUE(XMLType(report_summary),'/report_repository_summary/sql/@sql_exec_start') sql_exec_start

  FROM dba_hist_reports

 WHERE component_name = 'sqlmonitor'

SELECT /*+ NO_XML_QUERY_REWRITE */ t.report_id, x1.sql_id, x1.plan_hash, x1.sql_exec_id, x1.elapsed_time/1000000 ELAP_SEC

FROM dba_hist_reports t    

   , xmltable('/report_repository_summary/sql'    

       PASSING xmlparse(document t.report_summary)    

       COLUMNS    

         sql_id                path '@sql_id'     

       , sql_exec_start        path '@sql_exec_start'    

       , sql_exec_id           path '@sql_exec_id'      

       , status                path 'status'    

       , sql_text    path 'sql_text'

       , first_refresh_time    path 'first_refresh_time'

       , last_refresh_time     path 'last_refresh_time'

       , refresh_count         path 'refresh_count'

       , inst_id               path 'inst_id'

       , session_id            path 'session_id'

       , session_serial        path 'session_serial'

       , user_id               path 'user_id'

       , username              path 'user'

       , con_id                path 'con_id'

       , con_name              path 'con_name'

       , modul                 path 'module'

       , action                path 'action'

       , service               path 'service'

       , program               path 'program'

       , plan_hash             path 'plan_hash'

       , is_cross_instance     path 'is_cross_instance'

       , dop    path 'dop'

       , instances             path 'instances'

       , px_servers_requested  path 'px_servers_requested'

       , px_servers_allocated  path 'px_servers_allocated'

       , duration              path 'stats/stat[@name="duration"]'  

       , elapsed_time          path 'stats/stat[@name="elapsed_time"]'  

       , cpu_time              path 'stats/stat[@name="cpu_time"]'  

       , user_io_wait_time     path 'stats/stat[@name="user_io_wait_time"]'

       , application_wait_time path 'stats/stat[@name="application_wait_time"]'

       , concurrency_wait_time path 'stats/stat[@name="concurrency_wait_time"]'

       , cluster_wait_time     path 'stats/stat[@name="cluster_wait_time"]'

       , plsql_exec_time       path 'stats/stat[@name="plsql_exec_time"]'

       , other_wait_time       path 'stats/stat[@name="other_wait_time"]'

       , buffer_gets           path 'stats/stat[@name="buffer_gets"]'

       , read_reqs             path 'stats/stat[@name="read_reqs"]'

       , read_bytes            path 'stats/stat[@name="read_bytes"]'

     ) x1 

where x1.elapsed_time/1000000 > 200

and   t.COMPONENT_NAME = 'sqlmonitor'

order by 5

/

==> Report Generation 

set long 1000000

set longsize 330

set longchunksize 1000000

set pagesize 0

set trim on 

set echo off

set feedback off 

set trimspool on 

select dbms_auto_report.report_repository_detail( RID=> &report_id , type=> 'TEXT' ) as  report  from dual ; 

or 

select dbms_auto_report.report_repository_detail( RID=> &report_id , type=> 'active' ) as  report  from dual ; 

Generating Database Performance Hub Report :

@?/rdbms/admin/perfhubrpt.sql

Syntax

DBMS_PERF.REPORT_PERFHUB (
   is_realtime          IN NUMBER   DEFAULT NULL,
   outer_start_time     IN DATE     DEFAULT NULL,
   outer_end_time       IN DATE     DEFAULT NULL,
   selected_start_time  IN DATE     DEFAULT NULL,
   selected_end_time    IN DATE     DEFAULT NULL,
   inst_id              IN NUMBER   DEFAULT NULL,
   dbid                 IN NUMBER   DEFAULT NULL,
   monitor_list_detail  IN NUMBER   DEFAULT NULL,
   workload_sql_detail  IN NUMBER   DEFAULT NULL,
   addm_task_detail     IN NUMBER   DEFAULT NULL,
   report_reference     IN VARCHAR2 DEFAULT NULL,
   report_level         IN VARCHAR2 DEFAULT NULL,
   type                 IN VARCHAR2 DEFAULT 'ACTIVE',
   base_path            IN VARCHAR2 DEFAULT NULL);
 RETURN CLOB;

 REPORT_PERFHUB Function Parameters

Parameter	Description
is_realtime	If 1, then real-time. If NULL (default) or 0, then historical mode.
outer_start_time	Start time of outer period shown in the time selector. If NULL (default): If is_realtime=0 (historical), then 24 hours before outer_end_time. If is_realtime=1 (realtime mode), then 1 hour before outer_end_time.
outer_end_time	End time of outer period shown in the time selector. If NULL (default), then latest AWR snapshot. If is_realtime=0 (historical), then the latest AWR snapshot If is_realtime=1 (realtime mode), this is the current time (and any input is ignored)
selected_start_time	Start time period of selection. If NULL (default) If is_realtime=0, then 1 hour before selected_end_time If is_realtime=1, then 5 minutes before selected_end_time
selected_end_time	End time period of selection. If NULL (default) If is_realtime=0, then latest AWR snapshot If is_realtime=1, then current time
inst_id	Instance ID to for which to retrieve data If -1, then current instance If number is specified, then for that instance If NULL (default), then all instances
dbid	DBID to query. If NULL, then current DBID. If is_realtime=1, then DBID must be the local DBID.
monitor_list_detail	Top N in SQL monitor list for which to retrieve SQL monitor details. If NULL (default), then retrieves top 10 If 0, then retrieves no monitor list details
workload_sql_detail	Top N in Workload Top SQL list to retrieve monitor details, If NULL (default), then retrieves top 10 If 0, then retrieves no monitor list details
addm_task_detail	Maximum N latest ADDM tasks to retrieve If NULL (default), retrieves available data but no more than N If 0, then retrieves no ADDM task details
report_reference	Must be NULL when used from SQL*Plus.
report_level	'typical' will get all tabs in performance hub
type	Report type: 'ACTIVE' (default) 'xml' returns XML
base_path	URL path for HTML resources since flex HTML requires access to external files. This is only valid for type='ACTIVE' and is typically not used. Default value will retrieve the required files from OTN.

 

Reference : 

Monitoring Database Performance Using Performance Hub Report (Doc ID 2436566.1)

https://docs.oracle.com/en/database/oracle/oracle-database/21/arpls/DBMS_PERF.html#GUID-85CD8AB9-B6E0-444F-91A5-762EB92A74E9 

How To Get Historical SQL Monitor Report For SQL Statements (Doc ID 2555350.1)

Force cleanup of temporary segments through DROP_SEGMENT event in Oracle database

We recently had scenario where  temp segments were not getting released  even though  no  active sessions were there  and  "alter tablespace temp  coalesce;"   was not helping  .   

This needs to be done only after oracle support  recommendation .and this  feature  surprisingly exists from Oracle version  8 . 

This routine does what SMON does in the background, i.e. drops temporary segments.

Before force dropping temp segment try to gracefully clean . Sometimes temp can be resized after restart of database 

 select sum(blocks*8/1024) size_mb from v$tempseg_usage where tablespace='TEMP';

Shrink TEMP Tablespace using alter tablespace command

SQL> ALTER TABLESPACE temp SHRINK SPACE KEEP 50M;.

Shrink TEMPFILE using alter tablespace command

SQL> ALTER TABLESPACE temp SHRINK TEMPFILE '/u01/app/oracle/oradata/TEST11G/temp01.dbf' KEEP 40M;

Shrink TEMP Tablespace to the smallest possible size:

SQL> ALTER TABLESPACE temp SHRINK SPACE;

DESCRIPTION : 

Finds all the temporary segments in a tablespace which are not currently locked and drops them.

PARAMETER : Level parameter used in command 

level - tablespace number+1. If the value is 2147483647 then

temp segments in ALL tablespaces are dropped, otherwise, only

segments in a tablespace whose number is equal to the LEVEL

specification are dropped.

Manually release the temporary segment, the utilization rate will not decrease, but the content of the temporary tablespace will be released

alter session set events 'immediate trace name DROP_SEGMENTS level 4'

Description: TS# of temp tablespace is 3, So TS#+1=4

View temp content details

select se.inst_id,se.username,se.sid,su.extents,su.blocks*to_number(rtrim(p.value)) as Space, tablespace,segtype,sql_text from gv$sort_usage su,gv$parameter p,gv $session se,gv$sql s

where p.name='db_block_size' and su.session_addr=se.saddr and s.hash_value=su.sqlhash and s.address=su.sqladdr order by

se.username,se.sid;

If the query finds that most of the temp temporary table space is lob temporary fields, you can set the 60025 event

alter system set event="60025 trace name context forever" scope=spfile;

Restart to take effect

References : 

EVENT: DROP_SEGMENTS - Forcing cleanup of TEMPORARY segments (Doc ID 47400.1)

Note 177334.1 Overview of Temporary Segments 

Note 35513.1 Removing 'Stray' TEMPORARY Segments

Note 61997.1 SMON - Temporary Segment Cleanup and Free Space Coalescing

NOTE:160426.1 - TEMPORARY Tablespaces : Tempfiles or Datafiles ?

Note 102339.1 Temporary Segments: What Happens When a Sort Occurs 

Note 1039341.6 Temporary Segments Are Not Being De-Allocated After a Sort 

Note 68836.1 How To Efficiently Drop (or Truncate) A Table With Many Extents

Note 132913.1 How To Free Temporary Segment in Temporary Tablespace Dynamically

Resize Of Temporary Tablespace with KEEP keyword not working (Doc ID 1663229.1)