| General Information |
| Note |
Client Side SQLNET.ORA client cache parameters are optional and they over-ride server settings.
The OCI_RESULT_CACHE_MAX_SIZE must be set in bytes and must be at least 32768. For 2M set it to 2048000.
OCI_RESULT_CACHE_MAX_SIZE = 2048000
OCI_RESULT_CACHE_MAX_RSET_SIZE = 1024000
OCI_RESULT_CACHE_MAX_RSET_ROWS = 100000 |
| Purpose |
Result Cache administration |
| Source |
{ORACLE_HOME}/rdbms/admin/dbmsrcad.sql |
| First Available |
11.1 |
| Constants |
| Name |
Data Type |
Value |
| STATUS_BYPS |
VARCHAR2(10) |
'BYPASS' |
| STATUS_CORR |
VARCHAR2(10) |
'SYNC' |
| STATUS_DISA |
VARCHAR2(10) |
'DISABLED |
| STATUS_ENAB |
VARCHAR2(10) |
'ENABLED' |
| STATUS_SYNC |
VARCHAR2(10) |
'SYNC' |
|
| Dependent Objects |
| ALL_OBJECTS |
GV$RESULT_CACHE_MEMORY |
| DBMS_OUTPUT |
GV$RESULT_CACHE_OBJECTS |
| DBMS_RC_LIB |
GV$RESULT_CACHE_STATISTICS |
| GV$CLIENT_RESULT_CACHE_STATS |
V$SGASTAT |
| GV$RESULT_CACHE_DEPENDENCY |
V$SGA_DYNAMIC_COMPONENTS |
|
| Result Cache Parameters |
set linesize 121
col name format a30
col value format a30
SELECT name, value, issys_modifiable, isses_modifiable
FROM v$parameter
WHERE name LIKE '%result%';
-- modifiable
-- ALTER SYSTEM SET result_cache_max_result=7 SCOPE=BOTH;
-- options: AUTO, MANUAL, and FORCE: MANUAL is the default
-- ALTER SYSTEM SET result_cache_mode='AUTO' SCOPE=BOTH;
-- ALTER SYSTEM SET result_cache_remote_expiration=0 SCOPE=BOTH;
-- not modifiable
-- client_result_cache_lag = 5000
-- result_cache_size = 'MANUAL'
-- client_result_cache_size = 0 |
| Result Cache Statistics |
desc gv$result_cache_statistics
set linesize 121
col name format a30
col value format 999999
SELECT name, value
FROM gv$result_cache_statistics; |
| Security Model |
Execute is granted to the DBA role |
| Subprograms |
|
| |
BYPASS (new 11.2.0.1 parameter)  |
| Set the bypass mode for the Result Cache.
When bypass mode is "on", cached results are no longer used and new results are not saved. When turned off, the cache resumes normal operation. |
dbms_result_cache.bypass(bypass_mode IN BOOLEAN, session IN BOOLEAN DEFAULT FALSE); |
BEGIN
dbms_result_cache.bypass(FALSE);
dbms_result_cache.flush;
END;
/
Note: With RAC this must be done on each node |
| |
| DELETE_DEPENDENCY (new 11.2.0.1) |
Deletes the specified dependency object from the Result Cache and invalidates results that used the dependency
Overload 1 |
dbms_result_cache.delete_dependency(owner IN VARCHAR2, name IN VARCHAR2) RETURN NUMBER; |
SELECT o.object_id, o.object_name, v.object_no
FROM all_objects o, gv$result_cache_dependency v
WHERE o.object_id = v.object_no;
SELECT COUNT(*)
FROM gv$result_cache_objects;
SELECT /*+ RESULT_CACHE */ srvr_id
FROM (
SELECT srvr_id, SUM(cnt) SUMCNT
FROM (
SELECT DISTINCT srvr_id, 1 AS CNT
FROM servers
UNION ALL
SELECT DISTINCT srvr_id, 1
FROM serv_inst)
GROUP BY srvr_id)
WHERE sumcnt = 2;
SELECT o.object_id, o.object_name, v.object_no
FROM all_objects o, gv$result_cache_dependency v
WHERE o.object_id = v.object_no;
SELECT COUNT(*)
FROM gv$result_cache_objects;
set serveroutput on
DECLARE
i NUMBER;
BEGIN
i := dbms_result_cache.delete_dependency(USER, 'SERVERS');
dbms_output.put_line(i);
END;
/
SELECT o.object_id, o.object_name, v.object_no
FROM all_objects o, gv$result_cache_dependency v
WHERE o.object_id = v.object_no;
SELECT COUNT(*)
FROM gv$result_cache_objects; |
| Overload 2 |
dbms_result_cache.delete_dependency(IN VARCHAR2, name IN VARCHAR2); |
| TBD |
| Overload 3 |
dbms_result_cache.delete_dependency(object_id IN NATURALN) RETURN NUMBER; |
| TBD |
| Overload 4 |
dbms_result_cache.delete_dependency(object_id IN NATURALN); |
| TBD |
| |
| FLUSH (new 11.2.0.1 parameter) |
Attempts to remove all the objects from the Result Cache, and depending on the arguments retains/releases the memory and retains/clears the statistics.
Overload 1 |
dbms_result_cache.flush(
retainMem IN BOOLEAN DEFAULT FALSE,
retainSta IN BOOLEAN DEFAULT FALSE,
global IN BOOLEAN DEFAULT FALSE)
RETURN BOOLEAN; |
set serveroutput on
BEGIN
IF dbms_result_cache.flush THEN
dbms_output.put_line('Flush Successful');
ELSE
dbms_output.put_line('Flush Failure');
END IF;
END;
/ |
| Overload 2 |
dbms_result_cache.flush(
retainMem IN BOOLEAN DEFAULT FALSE,
retainSta IN BOOLEAN DEFAULT FALSE,
global IN BOOLEAN DEFAULT FALSE); |
| exec dbms_result_cache.flush(FALSE, TRUE); |
| |
| INVALIDATE |
Invalidates all the result-set objects that dependent upon the specified dependency object
Overload 1 |
dbms_result_cache.invalidate(owner IN VARCHAR2, name IN VARCHAR2)
RETURN NUMBER; |
| See DEMO below |
| Overload 2 |
dbms_result_cache.invalidate(owner IN VARCHAR2, name IN VARCHAR2); |
| See DEMO below |
| Overload 3 |
dbms_result_cache.invalidate(object_id IN NATURALN) RETURN NUMBER; |
| See DEMO below |
| Overload 4 |
dbms_result_cache.invalidate(object_id IN NATURALN); |
| See DEMO below |
| |
| INVALIDATE_OBJECT |
Invalidates the specified result-set object(s)
Overload 1 |
dbms_result_cache.invalidate_object(id IN NATURALN) RETURN NUMBER; |
| See DEMO below |
| Overload 2 |
dbms_result_cache.invalidate_object(id IN NATURALN); |
| See DEMO below |
| Overload 3 |
dbms_result_cache.invalidate_object(cache_id IN VARCHAR) RETURN NUMBER; |
| See DEMO below |
| Overload 4 |
dbms_result_cache.invalidate_object(cache_id IN VARCHAR); |
| See DEMO below |
| |
| MEMORY_REPORT |
| Produces the memory usage report for the Result Cache |
dbms_result_cache.memory_report(detailed IN BOOLEAN DEFAULT FALSE); |
set serveroutput on
exec dbms_result_cache.memory_report;
exec dbms_result_cache.memory_report(TRUE); |
| Result Cache Memory Report Sample |
R e s u l t C a c h e M e m o r y R e p o r t
[Parameters]
Block Size = 1K bytes
Maximum Cache Size = 209728K bytes (209728 blocks) Maximum Result Size = 10486K bytes (10486 blocks) [Memory] Total Memory = 12706360 bytes [0.039% of the Shared Pool] ... Fixed Memory = 79272 bytes [0.000% of the Shared Pool] ....... Cache Mgr = 152 bytes ....... Memory Mgr = 200 bytes ....... Bloom Fltr = 2K bytes ....... State Objs = 76872 bytes ... Dynamic Memory = 12627088 bytes [0.039% of the Shared Pool] ....... Overhead = 175248 bytes
........... Hash Table = 64K bytes (4K buckets)
........... Chunk Ptrs = 52432 bytes (6554 slots)
........... Chunk Maps = 26216 bytes
........... Miscellaneous = 31064 bytes
....... Cache Memory = 12160K bytes (12160 blocks) ........... Unused Memory = 5 blocks ........... Used Memory = 12155 blocks ............... Dependencies = 149 blocks (4 count) ............... Results = 12006 blocks
................... SQL = 3089 blocks (465 count)
................... PLSQL = 8917 blocks (8917 count) |
| |
| STATUS |
| Returns Result Cache status |
dbms_result_cache.status RETURN VARCHAR2 |
col status format a40
SELECT dbms_result_cache.status
FROM dual; |
| |
| SQL Demos |
| Manual Result Cache Demo |
SELECT dbms_result_cache.status
FROM dual;
col value format a30
SELECT name, value
FROM gv$parameter
WHERE name LIKE '%result%';
SELECT COUNT(*)
FROM gv$result_cache_objects;
/* if cached objects
set serveroutput on
BEGIN
IF dbms_result_cache.flush THEN
dbms_output.put_line('Flush Successful');
ELSE
dbms_output.put_line('Flush Failure');
END IF;
END;
/
SELECT COUNT(*)
FROM gv$result_cache_objects;
*/
SELECT srvr_id
FROM (
SELECT srvr_id, SUM(cnt) SUMCNT
FROM (
SELECT DISTINCT srvr_id, 1 AS CNT
FROM servers
UNION ALL
SELECT DISTINCT srvr_id, 1
FROM serv_inst)
GROUP BY srvr_id)
WHERE sumcnt = 2;
conn / as sysdba
SELECT COUNT(*)
FROM gv$result_cache_objects;
conn uwclass/uwclass
SELECT /*+ RESULT_CACHE */ srvr_id
FROM (
SELECT srvr_id, SUM(cnt) SUMCNT
FROM (
SELECT DISTINCT srvr_id, 1 AS CNT
FROM servers
UNION ALL
SELECT DISTINCT srvr_id, 1
FROM serv_inst)
GROUP BY srvr_id)
WHERE sumcnt = 2;
-- cache object identification
conn / as sysdba
SELECT o.object_id, o.object_name, v.object_no
FROM all_objects o, gv$result_cache_dependency v
WHERE o.object_id = v.object_no;
SELECT COUNT(*)
FROM gv$result_cache_objects;
set linesize 121
set pagesize 25
col name format a45
col row_size_min format 99999
col cache_id format a30
col cache_key format a30
-- namespace can be SQL or PL/SQL
SELECT id, type, status, name, namespace
depend_count
FROM gv$result_cache_objects
ORDER BY 1;
SELECT id, creation_timestamp, depend_count, scan_count
FROM gv$result_cache_objects
ORDER BY 1;
SELECT id, block_count, scn, column_count, row_count, row_size_max,
row_size_min, row_size_avg
FROM gv$result_cache_objects
ORDER BY 1;
SELECT id, build_time, lru_number, object_no, invalidations, cache_id,
cache_key
FROM gv$result_cache_objects
ORDER BY 1;
SELECT id, offset, free, object_id
FROM gv$result_cache_memory
ORDER BY id;
exec dbms_result_cache.flush(FALSE, TRUE);
SELECT COUNT(*)
depend_count
FROM gv$result_cache_objects; |
| Automatic Result Cache Demo |
conn / as sysdba
GRANT SELECT on gv_$result_cache_objects TO uwclass;
SELECT COUNT(*)
depend_count
FROM gv$result_cache_objects;
SELECT name, value
FROM gv$parameter
WHERE name LIKE '%result%';
ALTER SYSTEM SET result_cache_mode = 'AUTO' SCOPE=BOTH;
conn uwclass/uwclass
SELECT COUNT(*)
depend_count
FROM gv$result_cache_objects;
set linesize 121
col name format a25
col cache_id format a30
col name format a20
col status format a15
SELECT id, offset, free, object_id
FROM gv$result_cache_memory
ORDER BY id;
SELECT id, type, status, cache_id, name, scn
FROM gv$result_cache_objects
ORDER BY 1;
SELECT MAX(SUBSTR(netaddress,1,3))
FROM servers;
SELECT id, type, status, cache_id, name, scn
FROM gv$result_cache_objects
ORDER BY 1;
SELECT MAX(line_number)
FROM airplanes
WHERE customer_id = 'DAL';
-- sequentially invalidate objects using multiple overloads |
| |
| PL/SQL Demos |
| Manual PL/SQL Invocation |
SELECT dbms_result_cache.status
FROM dual;
SELECT name, value
FROM gv$parameter
WHERE name LIKE '%result%';
SELECT COUNT(*)
FROM gv$result_cache_objects;
CREATE OR REPLACE FUNCTION nocache(p_srvr_id IN servers.srvr_id%TYPE) RETURN BOOLEAN IS
srvrow servers%ROWTYPE;
BEGIN
SELECT *
INTO srvrow
FROM servers
WHERE srvr_id = p_srvr_id;
RETURN TRUE;
EXCEPTION
WHEN OTHERS THEN
RETURN FALSE;
END nocache;
/
set timing on
DECLARE
b BOOLEAN;
BEGIN
FOR i IN 1 .. 10 LOOP
FOR i IN 1 .. 618 LOOP
IF nocache(i) THEN
NULL;
END IF;
END LOOP;
END LOOP;
END;
/
/* Note: In 11gR1 if the RELIES ON information is not provided you can receive invalid results.
In 11gR2 if the information is omitted the database determines it automagically */
CREATE OR REPLACE FUNCTION rcache(p_srvr_id IN servers.srvr_id%TYPE)
RETURN BOOLEAN RESULT_CACHE RELIES_ON(servers) IS
srvrow servers%ROWTYPE;
BEGIN
SELECT *
INTO srvrow
FROM servers
WHERE srvr_id = p_srvr_id;
RETURN TRUE;
EXCEPTION
WHEN OTHERS THEN
RETURN FALSE;
END rcache;
/
set timing on
DECLARE
b BOOLEAN;
BEGIN
FOR i IN 1 .. 10 LOOP
FOR i IN 1 .. 618 LOOP
IF rcache(i) THEN
NULL;
END IF;
END LOOP;
END LOOP;
END;
/ |
| |
| Related Queries |
| Result Cache Performance |
SELECT inst_id, sid, serial#, username, logon_time,
ROUND((sysdate-logon_time)*1440) timeonline_min, a.*
FROM gv$session, (
SELECT inst_id instance_number,sql_id, sql_text,
ROUND((conc_wait_sec_exec/elap_sec_exec)*100) con_perc,
ROUND((clu_wait_sec_exec/elap_sec_exec)*100) clust_perc,
ROUND((user_io_wait_sec_exec/elap_sec_exec)*100) io_perc,
conc_wait_sec_exec, clu_wait_sec_exec, user_io_wait_sec_exec,
cpu_time_sec_exec , elap_sec_exec, buffer_gets,
ROUND((buffer_gets*32678)/1024/1024/1024) buffer_gb,
disk_reads, rows_processed, module, service, action
FROM (
SELECT inst_id, sql_id, sql_text,
ROUND((concurrency_wait_time/1000000)/DECODE(executions,NULL,1,0,1,executions),2) conc_wait_sec_exec,
ROUND((cluster_wait_time/1000000)/DECODE(executions,NULL,1,0,1,executions),2) clu_wait_sec_exec ,
ROUND((user_io_wait_time/1000000)/DECODE(executions,NULL,1,0,1,executions),2) user_io_wait_sec_exec,
ROUND((direct_writes/DECODE(executions,NULL,1,0,1,executions)),2) direct_writes_exec,
ROUND((cpu_time/1000000)/DECODE(executions,NULL,1,0,1,executions),2) cpu_time_sec_exec,
ROUND(( elapsed_time/1000000)/DECODE(executions,NULL,1,0,1,executions),2) elap_sec_exec,
ROUND((io_interconnect_bytes/DECODE(executions,NULL,1,0,1,executions)),2) io_inter_by_exec,
concurrency_wait_time, cluster_wait_time, user_io_wait_time, direct_writes,
cpu_time, elapsed_time, io_interconnect_bytes,
ROUND(sorts/DECODE(executions,NULL,1,0,1,executions),2) sort_exec,
fetches, rows_processed, executions, parse_calls,
ROUND(disk_reads/DECODE(executions,NULL,1,0,1,executions),2) disk_exec,
ROUND(buffer_gets/DECODE(executions, NULL, 1, 0, 1, executions),2) buff_exec,
service, module, action, buffer_gets, disk_reads
FROM gv$sql
WHERE users_opening > 0
AND elapsed_time/DECODE(executions,NULL,1,0,1,executions) >= 18000)) a
WHERE a.sql_id=gv$session.sql_id
AND a.instance_number=gv$session.inst_id; |
|
