Result cache - enterprise only?
Hi,
I can't find this anywhere: is result cache only available for enterpise version?
result_cache_max_size is always reset to 0 on standard edition...
Thanks
http://www.oracle.com/technology/products/database/oracle11g/pdf/database-11g-product-family-technical-whitepaper.pdf
==================================
Dion Cho - Oracle Performance Storyteller
http://dioncho.wordpress.com (english)
http://ukja.tistory.com (korean)
http://dioncho.blogspot.com (japanese)
==================================
Similar Messages
-
How to Enable Result Cache in 11g XE ?
Does anyone know how to enable the result cache in 11g XE?
I've tired startup/shut down immediate with various ALTER SYSTEM commands (see below) but result_cache_max_size still defaults to zero when the database comes back up.
ALTER SYSTEM SET result_cache_max_size = 2M SCOPE = SPFILE;
ALTER SYSTEM SET result_cache_max_size = 2M SCOPE = BOTH;
ALTER SYSTEM RESET result_cache_max_size SCOPE = SPFILE SID='*';
Any advice would be helpful.
ThanksIn the [Licensing document|http://download.oracle.com/docs/cd/E11882_01/license.112/e10594/editions.htm#CJACGHEB] , in the 'performance' section of the table, the result cache is only available on Enterprise and not Standard, so I wouldn't expect it to work in Express Edition
-
Is result cache, part of PGA or SGA(Shared Pool)
Is result cache, part of PGA or SGA(Shared Pool). whats is its stand when is is in a dedicated server or a RAC environment
Server query result cache can only be in SGA otherwise it could not be shared: http://download.oracle.com/docs/cd/E11882_01/server.112/e16638/memory.htm#BGBGEACF
Edited by: P. Forstmann on 28 sept. 2010 09:30 -
Hello everyone,
I have a question regarding the use of the client result cache but first of all here are the informations about my database:
SQL> SELECT * FROM v$version;
BANNER
Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 - 64bit Production
PL/SQL Release 11.2.0.1.0 - Production
CORE 11.2.0.1.0 Production
TNS for Linux: Version 11.2.0.1.0 - Production
NLSRTL Version 11.2.0.1.0 - Production
I have installed the Oracle Client Tools on my clientmachine. It has a tnsnames.ora like this:
ORCL =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = TCP)(HOST = FEA11-119SRV)(PORT = 1521))
(CONNECT_DATA =
(SERVICE_NAME = orcl.local)
The Client Result Cache is configured in the sqlnet.ora.
ADR_BASE = /u01/app/oracle
OCI_RESULT_CACHE_MAX_SIZE= 2048000
OCI_RESULT_CACHE_MAX_RSET_SIZE = 1024000
NAMES.DIRECTORY_PATH = (EZCONNECT, TNSNAMES, HOSTNAME)
The Databaseserver is configured like that:
SQL> col name format a30
SQL> col value format a30
SQL> SELECT name, value
2 FROM v$system_parameter
3 WHERE name LIKE '%result_cache%';
NAME VALUE
result_cache_mode MANUAL
result_cache_max_size 0
result_cache_max_result 5
result_cache_remote_expiration 0
client_result_cache_size 1073741824
client_result_cache_lag 3000
After configuring client an server I try the followign SQL-Statement on the clientmachine:
sqlplus oracle/password@orcl
set autotrace traceonly explain
SELECT /*+ result_cache */ *
FROM testtable;
SQL
The execution plan show two operations: "SELECT STATEMENT" and "TABLE ACCESS FULL" but no the "RESULT CACHE" operation.
Did I miss something?
Any help would be appreciated
Florian W.result_cache_max_size 0
That means the result cache is disabled. You need to set it to a non-zero value. That is the maximum ammount of memory, in bytes, the database will allocate on the shared pool to dedicate it to the result cache for all requests.
By the way, OCI_RESULT_CACHE_MAX_SIZE is optional. By default the sessions will have the maximum size they can occupy on the cache determined by CLIENT_RESULT_CACHE parameter, the client (OCI) side parameters override that.
result_cache_mode MANUAL
Another thing to consider is RESULT_CACHE_MODE in MANUAL, that will cause only the statements with the RESULT_CACHE hint on it to be cached on the result cache. You can also set result cache to mode FORCE on specific tables with alter table command.
Regards -
Possible result cache problem 11GR1;;Plz Help me :)
Hello,
I just finished installing Oracle 11g Enterprise Edition on my laptop,under windows XP 32 Bit,
Just run to test the result cache ,It seems the result cache does not work for me ;
Please see the demonstration below and help me to undertsand:
(I am the only person connected to the database and I only have one session conneted )
Connected to Oracle Database 11g Enterprise Edition Release 11.1.0.6.0
Connected as SYS
SQL> set timi on
SQL> select * from v$version;
BANNER
Oracle Database 11g Enterprise Edition Release 11.1.0.6.0 - Production
PL/SQL Release 11.1.0.6.0 - Production
CORE 11.1.0.6.0 Production
TNS for 32-bit Windows: Version 11.1.0.6.0 - Production
NLSRTL Version 11.1.0.6.0 - Production
Executed in 0.031 seconds
SQL> ----result cache demonstration
SQL> ----clear the server result cache
SQL> exec dbms_result_cache.Flush
PL/SQL procedure successfully completed
Executed in 0 seconds
SQL> ---run a query to load the server result cache
SQL>
SQL> SELECT /*+ result_cache */
2 H.DEPARTMENT_ID, H.DEPARTMENT_NAME, H.MANAGER_ID, COUNT(*)
3 FROM HR.DEPARTMENTS H
4 GROUP BY H.DEPARTMENT_ID, H.DEPARTMENT_NAME, H.MANAGER_ID
5 ;
DEPARTMENT_ID DEPARTMENT_NAME MANAGER_ID COUNT(*)
10 Administration 200 1
30 Purchasing 114 1
50 Shipping 121 1
60 IT 103 1
70 Public Relations 204 1
200 Operations 1
210 IT Support 1
230 IT Helpdesk 1
90 Executive 100 1
100 Finance 108 1
140 Control And Credit 1
150 Shareholder Services 1
160 Benefits 1
220 NOC 1
250 Retail Sales 1
130 Corporate Tax 1
110 Accounting 205 1
270 Payroll 1
40 Human Resources 203 1
170 Manufacturing 1
DEPARTMENT_ID DEPARTMENT_NAME MANAGER_ID COUNT(*)
260 Recruiting 1
20 Marketing 201 1
120 Treasury 1
80 Sales 145 1
180 Construction 1
190 Contracting 1
240 Government Sales 1
27 rows selected
Executed in 0.282 seconds
SQL> --*-response time is 0.282 seconds*
SQL> ---Show the result information from v$result_cache_objects : is the result cache is valid ?
SQL> --- The space used also?
SQL>
SQL> SELECT ID,
2 NAME,
3 TYPE,
4 STATUS,
5 BLOCK_COUNT,
6 ROW_COUNT * ROW_SIZE_AVG AS SPACE_FOR_ROWS,
7 SPACE_OVERHEAD
8 FROM V$RESULT_CACHE_OBJECTS V
9 ;
ID NAME TYPE STATUS BLOCK_COUNT SPACE_FOR_ROWS SPACE_OVERHEAD
0 HR.DEPARTMENTS Dependency Published 1 0 0
1 SELECT /*+ result_cache */ Result Published 1 675 320
H.DEPARTMENT_ID, H.DEPARTMENT_NAME, H.MANAGER_ID, COUNT(*)
FROM HR.DEPARTMENTS H
GROUP BY H.DEPAR
Executed in 0.141 seconds
SQL> ---we run again our query
SQL>
SQL> SELECT /*+ result_cache */
2 H.DEPARTMENT_ID, H.DEPARTMENT_NAME, H.MANAGER_ID, COUNT(*)
3 FROM HR.DEPARTMENTS H
4 GROUP BY H.DEPARTMENT_ID, H.DEPARTMENT_NAME, H.MANAGER_ID
5 ;
DEPARTMENT_ID DEPARTMENT_NAME MANAGER_ID COUNT(*)
10 Administration 200 1
30 Purchasing 114 1
50 Shipping 121 1
60 IT 103 1
70 Public Relations 204 1
200 Operations 1
210 IT Support 1
230 IT Helpdesk 1
90 Executive 100 1
100 Finance 108 1
140 Control And Credit 1
150 Shareholder Services 1
160 Benefits 1
220 NOC 1
250 Retail Sales 1
130 Corporate Tax 1
110 Accounting 205 1
270 Payroll 1
40 Human Resources 203 1
170 Manufacturing 1
DEPARTMENT_ID DEPARTMENT_NAME MANAGER_ID COUNT(*)
260 Recruiting 1
20 Marketing 201 1
120 Treasury 1
80 Sales 145 1
180 Construction 1
190 Contracting 1
240 Government Sales 1
27 rows selected
*Executed in 0.297 seconds*
SQL> Why the first is faster than the second?
thanks a lot,
Edited by: Ora-Wiss on Apr 3, 2010 2:17 PMI have been using 11g from quite some time now in my sessions and already have started sessions over 11gr2 as well and I can't recall that I ever faced this thing. And I just did show the same to you on my personal system as well. But nevermind, here is one more run with the database being restarted and the same code being run.
SQL> select * from v$version;
BANNER
Oracle Database 11g Enterprise Edition Release 11.1.0.6.0 - Production
PL/SQL Release 11.1.0.6.0 - Production
CORE 11.1.0.6.0 Production
TNS for 32-bit Windows: Version 11.1.0.6.0 - Production
NLSRTL Version 11.1.0.6.0 - Production
Elapsed: 00:00:00.00
SQL> startup force
ORACLE instance started.
Total System Global Area 171573248 bytes
Fixed Size 1331936 bytes
Variable Size 125832480 bytes
Database Buffers 37748736 bytes
Redo Buffers 6660096 bytes
Database mounted.
Database opened.
SQL> exec dbms_result_cache.Flush;
PL/SQL procedure successfully completed.
Elapsed: 00:00:00.06
SQL> SELECT /*+ result_cache */ H.DEPARTMENT_ID, H.DEPARTMENT_NAME, H.MANAGER_ID, COUNT(*) FROM HR.DEPARTMENTS H GROUP BY H.DEP
ARTMENT_ID, H.DEPARTMENT_NAME, H.MANAGER_ID;
DEPARTMENT_ID DEPARTMENT_NAME MANAGER_ID COUNT(*)
10 Administration 200 1
30 Purchasing 114 1
50 Shipping 121 1
60 IT 103 1
70 Public Relations 204 1
200 Operations 1
210 IT Support 1
230 IT Helpdesk 1
90 Executive 100 1
100 Finance 108 1
140 Control And Credit 1
DEPARTMENT_ID DEPARTMENT_NAME MANAGER_ID COUNT(*)
150 Shareholder Services 1
160 Benefits 1
220 NOC 1
250 Retail Sales 1
130 Corporate Tax 1
110 Accounting 205 1
270 Payroll 1
40 Human Resources 203 1
170 Manufacturing 1
260 Recruiting 1
20 Marketing 201 1
DEPARTMENT_ID DEPARTMENT_NAME MANAGER_ID COUNT(*)
120 Treasury 1
80 Sales 145 1
180 Construction 1
190 Contracting 1
240 Government Sales 1
27 rows selected.
Elapsed: 00:00:00.15
SQL> SELECT /*+ result_cache */ H.DEPARTMENT_ID, H.DEPARTMENT_NAME, H.MANAGER_ID, COUNT(*) FROM HR.DEPARTMENTS H GROUP BY H.DEP
ARTMENT_ID, H.DEPARTMENT_NAME, H.MANAGER_ID;
DEPARTMENT_ID DEPARTMENT_NAME MANAGER_ID COUNT(*)
10 Administration 200 1
30 Purchasing 114 1
50 Shipping 121 1
60 IT 103 1
70 Public Relations 204 1
200 Operations 1
210 IT Support 1
230 IT Helpdesk 1
90 Executive 100 1
100 Finance 108 1
140 Control And Credit 1
DEPARTMENT_ID DEPARTMENT_NAME MANAGER_ID COUNT(*)
150 Shareholder Services 1
160 Benefits 1
220 NOC 1
250 Retail Sales 1
130 Corporate Tax 1
110 Accounting 205 1
270 Payroll 1
40 Human Resources 203 1
170 Manufacturing 1
260 Recruiting 1
20 Marketing 201 1
DEPARTMENT_ID DEPARTMENT_NAME MANAGER_ID COUNT(*)
120 Treasury 1
80 Sales 145 1
180 Construction 1
190 Contracting 1
240 Government Sales 1
27 rows selected.
Elapsed: 00:00:00.01
SQL>As you can see, I can't reproduce.
HTH
Aman.... -
Hi,
i am not sure, whether the new feature "Client Result Cache" for OCI - Connections is an enterprise only feature or not.
The Licensing Information at http://docs.oracle.com/cd/E11882_01/license.112/e10594/editions.htm#CJACGHEB shows this three features are enterprise only:
Client Side Query Cache
Query Results Cache
PL/SQL Function Result Cache
Which of these are pointing to Client Result Cache? Is it the Query Results Cache? Or something else?
As an Hint, i am unable to activate the feature on standard edition databases, but i am not sure, if this is the reason or if i am just making some mistakes in configuration/testing.
Thanks in advance
Joergwe stopped all tests, because it seems to be a enterprise edition only feature.
-
Oracle 11g/R2 Query Result Cache - Incremental Update
Hi,
In Oracle 11g/R2, I created replica of HR.Employees table & executed the following statement (+Although using SUM() function is non-logical in this case, but just testifying the result+)
STEP - 1
SELECT /+ RESULT_CACHE */ employee_id, first_name, last_name, SUM(salary)*
FROM HR.Employees_copy
WHERE department_id = 20
GROUP BY employee_id, first_name, last_name;
EMPLOYEE_ID FIRST_NAME LAST_NAME SUM(SALARY)
202 Pat Fay 6000
201 Michael Hartstein 13000
Elapsed: 00:00:00.01
Execution Plan
Plan hash value: 3837552314
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
| 0 | SELECT STATEMENT | | 2 | 130 | 4 (25)| 00:00:01 |
| 1 | RESULT CACHE | 3acbj133x8qkq8f8m7zm0br3mu | | | | |
| 2 | HASH GROUP BY | | 2 | 130 | 4 (25)| 00:00:01 |
|* 3 | TABLE ACCESS FULL | EMPLOYEES_COPY | 2 | 130 | 3 (0)| 00:00:01 |
-------------------------------------------------------------------------------------------------- Statistics
0 recursive calls
0 db block gets
0 consistent gets
0 physical reads
0 redo size
*690* bytes sent via SQL*Net to client
416 bytes received via SQL*Net from client
2 SQL*Net roundtrips to/from client
0 sorts (memory)
0 sorts (disk)
2 rows processed
STEP - 2
INSERT INTO HR.employees_copy
VALUES(200, 'Dummy', 'User','[email protected]',NULL, sysdate, 'MANAGER',5000, NULL,NULL,20);
STEP - 3
SELECT /*+ RESULT_CACHE */ employee_id, first_name, last_name, SUM(salary)
FROM HR.Employees_copy
WHERE department_id = 20
GROUP BY employee_id, first_name, last_name;
EMPLOYEE_ID FIRST_NAME LAST_NAME SUM(SALARY)
202 Pat Fay 6000
201 Michael Hartstein 13000
200 Dummy User 5000
Elapsed: 00:00:00.03
Execution Plan
Plan hash value: 3837552314
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
| 0 | SELECT STATEMENT | | 3 | 195 | 4 (25)| 00:00:01 |
| 1 | RESULT CACHE | 3acbj133x8qkq8f8m7zm0br3mu | | | | |
| 2 | HASH GROUP BY | | 3 | 195 | 4 (25)| 00:00:01 |
|* 3 | TABLE ACCESS FULL| EMPLOYEES_COPY | 3 | 195 | 3 (0)| 00:00:01 |
Statistics
0 recursive calls
0 db block gets
4 consistent gets
0 physical reads
0 redo size
*714* bytes sent via SQL*Net to client
416 bytes received via SQL*Net from client
2 SQL*Net roundtrips to/from client
0 sorts (memory)
0 sorts (disk)
3 rows processed
In the execution plan of STEP-3, against ID-1 the operation RESULT CACHE is shown which shows the result has been retrieved directly from Result cache. Does this mean that Oracle Server has Incrementally Retrieved the resultset?
Because, before the execution of STEP-2, the cache contained only 2 records. Then 1 record was inserted but after STEP-3, a total of 3 records was returned from cache. Does this mean that newly inserted row is retrieved from database and merged to the cached result of STEP-1?
If Oracle server has incrementally retrieved and merged newly inserted record, what mechanism is being used by the Oracle to do so?
Regards,
Wasif
Edited by: 965300 on Oct 15, 2012 12:25 AM965300 wrote:
Hi,
In Oracle 11g/R2, I created replica of HR.Employees table & executed the following statement (+Although using SUM() function is non-logical in this case, but just testifying the result+)
STEP - 1
SELECT /+ RESULT_CACHE */ employee_id, first_name, last_name, SUM(salary)*
FROM HR.Employees_copy
WHERE department_id = 20
GROUP BY employee_id, first_name, last_name;
EMPLOYEE_ID FIRST_NAME LAST_NAME SUM(SALARY)
202 Pat Fay 6000
201 Michael Hartstein 13000
Elapsed: 00:00:00.01
Execution Plan
Plan hash value: 3837552314
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
| 0 | SELECT STATEMENT | | 2 | 130 | 4 (25)| 00:00:01 |
| 1 | RESULT CACHE | 3acbj133x8qkq8f8m7zm0br3mu | | | | |
| 2 | HASH GROUP BY | | 2 | 130 | 4 (25)| 00:00:01 |
|* 3 | TABLE ACCESS FULL | EMPLOYEES_COPY | 2 | 130 | 3 (0)| 00:00:01 |
-------------------------------------------------------------------------------------------------- Statistics
0 recursive calls
0 db block gets
0 consistent gets
0 physical reads
0 redo size
*690* bytes sent via SQL*Net to client
416 bytes received via SQL*Net from client
2 SQL*Net roundtrips to/from client
0 sorts (memory)
0 sorts (disk)
2 rows processed
STEP - 2
INSERT INTO HR.employees_copy
VALUES(200, 'Dummy', 'User','[email protected]',NULL, sysdate, 'MANAGER',5000, NULL,NULL,20);
STEP - 3
SELECT /*+ RESULT_CACHE */ employee_id, first_name, last_name, SUM(salary)
FROM HR.Employees_copy
WHERE department_id = 20
GROUP BY employee_id, first_name, last_name;
EMPLOYEE_ID FIRST_NAME LAST_NAME SUM(SALARY)
202 Pat Fay 6000
201 Michael Hartstein 13000
200 Dummy User 5000
Elapsed: 00:00:00.03
Execution Plan
Plan hash value: 3837552314
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
| 0 | SELECT STATEMENT | | 3 | 195 | 4 (25)| 00:00:01 |
| 1 | RESULT CACHE | 3acbj133x8qkq8f8m7zm0br3mu | | | | |
| 2 | HASH GROUP BY | | 3 | 195 | 4 (25)| 00:00:01 |
|* 3 | TABLE ACCESS FULL| EMPLOYEES_COPY | 3 | 195 | 3 (0)| 00:00:01 |
Statistics
0 recursive calls
0 db block gets
4 consistent gets
0 physical reads
0 redo size
*714* bytes sent via SQL*Net to client
416 bytes received via SQL*Net from client
2 SQL*Net roundtrips to/from client
0 sorts (memory)
0 sorts (disk)
3 rows processed
In the execution plan of STEP-3, against ID-1 the operation RESULT CACHE is shown which shows the result has been retrieved directly from Result cache. Does this mean that Oracle Server has Incrementally Retrieved the resultset?
Because, before the execution of STEP-2, the cache contained only 2 records. Then 1 record was inserted but after STEP-3, a total of 3 records was returned from cache. Does this mean that newly inserted row is retrieved from database and merged to the cached result of STEP-1?
If Oracle server has incrementally retrieved and merged newly inserted record, what mechanism is being used by the Oracle to do so?
Regards,
Wasif
Edited by: 965300 on Oct 15, 2012 12:25 AMNo, the RESULT CACHE operation doesn't necessarily mean that the results are retrieved from there. It could be being
written to there.
Look at the number of consistent gets: it's zero in the first step (I assume you had already run this query before) and I would
conclude that the data is being read from the result cache.
In the third step there are 4 consistent gets. I would conclude that the data is being written to the result cache, a fourth step repeating
the SQL should show zero consistent gets and that would be the results being read. -
Oracle result cache and functions
Hi All,
I am on 11.2 in Linux.
I want to use Oracle's result cache to cache results of (user defined) functions, which we use in SELECT commands.
My question is, does result caching work for deterministic and non-deterministic functions ?
Just curious, how Oracle keeps track of changes being made which affect a function's return value?
Thoughts please.
Thanks in advanceI want to ... cache results of (user defined) functions, which we use in SELECT commands.You have four choices:
1. Subquery caching - (wrap function call in SELECT) useful for repeated function calls in a single SELECT
2. Marking function as DETERMINISTIC - inconsistent results across versions, deterministic best reserved for function-based indexes only
3. Result Cache
4. Move function logic out of function and inline to the main SQL statement.
The biggest downside of any function call that is inline to SQL is that it bypasses the read consistency mechanism, actually that's probably the second biggest downside. The biggest downside is normally that their misuse kills performance.
If your function itself contains SQL then you should seriously reconsider whether you should be using a function.
does result caching work for deterministic and non-deterministic functions ?Result cache knows nothing about determinism so yes it should be applied regardless.
Oracle keeps track of changes being made which affect a function's return value?See v$result_cache_dependency.
The mechanism is very blunt, there is no fine-grained tracking of data changes that may affect your result.
It's as simple as function F1 relies on table T1. If the data in table T1 changes, invalidate the results in the result cache for F1. -
If sga_target set explicitly, result cache become disabled
hi all,
I am using 11g R2 and automatic memory management. I realized something. if I explicitly declare sga_target parameter in parameter file, result cache become disabled.
as you know if you use automatic memory management, sga_target is set to 0 automatically already but if I write that to the parameter file than whatever I set for result_cache_max_size parameter, instance always opens with result_cache_max_size=0 (I saw that in alert log).
is there any reason for that ?
here is my pfile contents.
orcl.__db_cache_size=922746880
orcl.__java_pool_size=33554432
orcl.__large_pool_size=16777216
orcl.__oracle_base='C:\app\paranoyakX'#ORACLE_BASE set from environment
orcl.__pga_aggregate_target=838860800
orcl.__sga_target=1258291200
orcl.__shared_io_pool_size=0
orcl.__shared_pool_size=251658240
orcl.__streams_pool_size=16777216
*.audit_file_dest='C:\app\paranoyakX\admin\orcl\adump'
*.audit_trail='DB_EXTENDED'
*.compatible='11.2.0.0.0'
*.control_files='C:\app\paranoyakX\oradata\orcl\control01.ctl','C:\app\paranoyakX\flash_recovery_area\orcl\control02.ctl'
*.db_16k_cache_size=0
*.db_4k_cache_size=0
*.db_block_size=8192
*.db_domain='oracle.com'
*.db_flashback_retention_target=1000
*.db_keep_cache_size=0
*.db_name='orcl'
*.db_recovery_file_dest='C:\app\paranoyakX\flash_recovery_area'
*.db_recovery_file_dest_size=10737418240
*.diagnostic_dest='C:\app\paranoyakX'
*.dispatchers='(PROTOCOL=TCP) (SERVICE=orclXDB)'
*.memory_max_target=34359738368
*.memory_target=2097152000
*.nls_language='TURKISH'
*.nls_territory='TURKEY'
*.open_cursors=300
*.pga_aggregate_target=528482304
*.processes=150
*.remote_login_passwordfile='EXCLUSIVE'
*.resource_limit=TRUE
*.undo_tablespace='UNDOTBS1'
*.result_cache_max_size=5000000
*.sga_target=0I would suggest that you pay more attention to documentation and don't jump to conclusion in a haste. Just because the parameter result_cache_max_size is set to 0, it does not mean that the result cache in itself is disabled. This is the maximum size of the result cache. See below,
[oracle@edbar2p0-orcl ~]$ sqlplus / as sysdba
SQL*Plus: Release 11.2.0.1.0 Production on Thu Jul 14 08:35:00 2011
Copyright (c) 1982, 2009, Oracle. All rights reserved.
Connected to:
Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 - Production
With the Partitioning, Automatic Storage Management, OLAP, Data Mining
and Real Application Testing options
SQL> sho parameter result
NAME TYPE VALUE
client_result_cache_lag big integer 3000
client_result_cache_size big integer 0
result_cache_max_result integer 5
result_cache_max_size big integer 1184K
result_cache_mode string MANUAL
result_cache_remote_expiration integer 0
SQL> show parameter sga
NAME TYPE VALUE
lock_sga boolean FALSE
pre_page_sga boolean FALSE
sga_max_size big integer 460M
sga_target big integer 0
SQL> set autot trace exp
selSQL> ect /*+ result_cache */ * from scott.dept;
Execution Plan
Plan hash value: 3383998547
| Id | Operation | Name | Rows | Bytes | Cost (
%CPU)| Time |
| 0 | SELECT STATEMENT | | 4 | 80 | 3
(0)| 00:00:01 |
| 1 | RESULT CACHE | 1c13q1afp56bq0jpnmysvywx7g | | |
| |
| 2 | TABLE ACCESS FULL| DEPT | 4 | 80 | 3
(0)| 00:00:01 |
Result Cache Information (identified by operation id):
1 - column-count=3; dependencies=(SCOTT.DEPT); name="select /*+ result_cache
*/ * from scott.dept"
SQL> exit
Disconnected from Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 - Production
With the Partitioning, Automatic Storage Management, OLAP, Data Mining
and Real Application Testing optionsThe value for the result_cache parameter is automatically set by oracle depending on either you have Memory_target/SGA_TARGET or Shared_Pool parameter set. Please see oracle documentation for more information.
HTH
Aman.... -
Hi,
I am trying to enable result cache feature at Oracle 11g R2 server. I am following the below steps but everytime the cache status is coming DISABLED. Please help me to correct it
1. I am setting the RESULT_CACHE_MAX_SIZE and RESULT_CACHE_MODE as below. Memory_Target is 1232M, so I chose to allocate 200M for result cache.
ALTER SYSTEM SET RESULT_CACHE_MODE=FORCE
System altered.
ALTER SYSTEM SET RESULT_CACHE_MAX_SIZE=200M
System altered.2. I am restarting the database
SHUTDOWN IMMEDIATE
STARTUP
3. I am querying the result cache status
SELECT DBMS_RESULT_CACHE.STATUS FROM DUAL
STATUS
DISABLEDI have configured other database servers for cache and its working fine. But i am not able to sort out what is going wrong in above scripts. Please help me if i am missing out some step.
Thanksselect * from v$version;you need "Enterprise Edition" http://docs.oracle.com/cd/B28359_01/license.111/b28287/editions.htm
for EE check this:
http://psoug.org/reference/dbms_result_cache.html
http://www.oracle.com/technetwork/articles/datawarehouse/vallath-resultcache-rac-284280.html
http://www.oracle-developer.net/display.php?id=503 -
Hi,
BANNER
Oracle Database 11g Enterprise Edition Release 11.2.0.3.0 - 64bit Production
PL/SQL Release 11.2.0.3.0 - Production
CORE 11.2.0.3.0 Production
TNS for Linux: Version 11.2.0.3.0 - Production
NLSRTL Version 11.2.0.3.0 - Production
SQL> show parameter result;
NAME TYPE VALUE
client_result_cache_lag big integer 3000
client_result_cache_size big integer 0
result_cache_max_result integer 5
result_cache_max_size big integer 10M
result_cache_mode string MANUAL
result_cache_remote_expiration integer 0
The above are the initialization parameters set and the DB version.
Now i have created a table as
create table objects as select * from dba_objects;
then issued the following query.
select /* result_cache */ object_Type,count(*) from objects group by object_type;
it appears that the results of the above query is not cached in the result cache. using
set autotrace traceonly explain confirms that there is no result cache or the CACHE_ID in the explain plan. also the v$result_cache_statistics confirm the same.
But after this when i issued the following statement.
alter session set result_cache_mode=force;
the same below sql statement again
select /* result_cache */ object_Type,count(*) from objects group by object_type;
it appears that now the result cache is being used.
My question is despite using the result_cache hint and trying the above statement when the result_cache_mode=auto/manual. The result cache is not being used or the results of the SQL statements are not being cached at all despite using the result_cache hint and the table being not used at all. and if i use the result_cache_mode=force then the result cache is being used.
Can any one please explain this behavior. Cursor_sharing is set to EXACT. and i am issuing the same SQL statement without any changes at all.
Thanks,There is a syntax problem with your queries:
select /* result_cache */.... is just a comment, not a hint. For creating a hint, you need "+": select /*+ result_cache */.... -
Hi,
I have read that there is SGA component called Result Cache. According to documentation:
The result cache buffers query results. If a query is run that
already has results in the result cache, the database returns
results from the result cache instead of rerunning the query. This
speeds up the execution of frequently run queries.
What happens when data in tables which are called by the query change. I think the old data still will be in cache and I always get the old data.
Peter D.Hi Peter
What happens when data in tables which are called by
the query change. I think the old data still will be in
cache and I always get the old data.The server result cache can return old data only for distributed queries (i.e. queries also retrieving data from other databases).
All local queries return the correct data. To do so, the cache entries are invalidated as required.
HTH
Chris Antognini
Author of Troubleshooting Oracle Performance, Apress 2008 (http://top.antognini.ch) -
Using the client result cache without the query result cache
I have constructed a client in C# using ODP.NET to connect to an Oracle database and want to perform client result caching for some of my queries.
This is done using a result_cache hint in the query.
select /*+ result_cache */ * from table
As far as I can tell query result caching on the server is done using the same hint, so I was wondering if there was any way to differentiate between the two? I want the query results to be cached on the client, but not on the server.
The only way I have found to do this is to disable all caching on the server, but I don't want to do this as I want to use the server cache for PL/SQL function results.
Thanks.e3a934c9-c4c2-4c80-b032-d61d415efd4f wrote:
I have constructed a client in C# using ODP.NET to connect to an Oracle database and want to perform client result caching for some of my queries.
This is done using a result_cache hint in the query.
select /*+ result_cache */ * from table
As far as I can tell query result caching on the server is done using the same hint, so I was wondering if there was any way to differentiate between the two? I want the query results to be cached on the client, but not on the server.
The only way I have found to do this is to disable all caching on the server, but I don't want to do this as I want to use the server cache for PL/SQL function results.
Thanks.
You haven't provided ANY information about how you configured the result cache. Different parameters are used for configuring the client versus the server result cache so you need to post what, if anything, you configured.
Post the code you executed when you set the 'client_result_cache_lag' and 'client_result_cache_size' parameters so we can see what values you used. Also post the results of querying those parameters after you set them that show that they really are set.
You also need to post your app code that shows that you are using the OCI statements are used when you want to use client side result cacheing.
See the OCI dev guide
http://docs.oracle.com/cd/B28359_01/appdev.111/b28395/oci10new.htm#sthref1491
Statement Caching in OCI
Statement caching refers to the feature that provides and manages a cache of statements for each session. In the server, it means that cursors are ready to be used without the need to parse the statement again. Statement caching can be used with connection pooling and with session pooling, and will improve performance and scalability. It can be used without session pooling as well. The OCI calls that implement statement caching are:
OCIStmtPrepare2()
OCIStmtRelease() -
Hi all,
As we know, there's a new feature in 11g, called 'result cache', this 'result cache' can be shared throughout the whole instance, but if I got it right, only sql query result and function return value are cached, right? how about the store procedure, I mean, procedure also has its 'return value'--the output parameter, could it benefit from this new feature?
Another question is, if my PL/SQL Function just retrieves the table and returns the result without any complicated calculation, is it necessary to enable the 'result cache' mechanism on this Function? because we already have 'db buffer cache' if the only thing we do is to query tables.
Many thanks.Hi Morven,
As of now, PL/SQL Result cache feature is only enabled for stored functions and not for procedures. This is due to the objectives they achieve. Functions are usually computative and procedures are for logic implementation.
And for enabling result caching feature for a function, you are the better judge as u can test the performance in both the case. But, i would support enabling the cache because oracle 11g provides Cache as a different SGA component. db_buffer_cache will also be used for buffering other data blocks and not the result sets.
Hope my explanation is fine. -
Hi,
How do I confirm if the result caching is working? This is on the latest download available for OSB - 11.1.1.3.
I tried to launch separate instances of caches, but could not confirm. Secondly, I also tried to enable caching support for a business service. I put in a hard coded expression in the cache token expression. I was not able to get that working.
Any ideas?
Regards,
Anand.
Edited by: user653362 on May 12, 2010 6:29 AM>
How do I confirm if the result caching is working? This is on the latest download available for OSB - 11.1.1.3.
>
Perhaps the simplest way is to check access log on your backend (business service). Arrange a simple test that will lead to repeated callouts (with the same request data) to your business service. Than you should see only one (the first) request logged in your backend.
The better way is to start another node of Coherence, connect to the OSB instance of Coherence and see what your cache looks like. Look at Coherence documentation for command line parameters:
http://coherence.oracle.com/display/COH35UG/Command+Line+Setting+Override+Feature
I was able to connect to the default OSB Coherence instance and list cached entries using this command:
java -Dtangosol.coherence.cluster=OSB-cluster -Dtangosol.coherence.clusteraddress=228.8.8.8 -Dtangosol.coherence.clusterport=9888 -Dtangosol.coherence.distributed.localstorage=true -Dtangosol.coherence.override=/opt/Oracle11g/user_projects/domains/osb11_domain/config/osb/coherence/osb-coherence-override.xml -Dtangosol.coherence.cacheconfig=/opt/Oracle11g/user_projects/domains/osb11_domain/config/osb/coherence/osb-coherence-cache-config.xml com.tangosol.net.CacheFactory
Maybe you are looking for
-
How can I get the Voiceover Keyboard shortcuts to show up in a form in which I can copy
I have low vision & have been trying to learn to use Voiceover on both my iPhone & my Mac mini for months. Very frustrating. 1. How can I get the Voiceover keyboard shortcut commans to show up in a form in which I can copy & paste them into a pages d
-
NI unzip changes file date and time stamp
A coworker this morning asked me about the NI-Unzip VI. It turns out that when the NI unzip VI unzips a file it changes the file dates to the date the file was unzipped. He also noted that NI-Unzip seems to be calling the Windows touch.exe to do this
-
Acrobat X - PDF Maker stopped autotext save in normal.dot
Hi Guys Does anyone meet this issue? When Acrobat PDFMaker is installed and enable, word 2003 will not be able save the autotext record in normal.dot. Any help is welcome. Cheers Eric
-
Very slow wi-fi connectivity past few months on mac-mini os x 10.4.11
Thanks Randy for my earlier post response. I'm using a 2007 Mac mini which runs on OS X Tiger 10.4.11. I am facing hard time connecting with Airpot ON and Wi-Fi...past few months? Almost all of the websites are taking long time to display. I'm able t
-
I have an Automator Folder action attached to my Downloads folder which moves any .jpg file to another folder where I normally place my images. It works for a while (automatically moving the .jpg files whenever a file is placed in the Downloads folde