OEM for shared pool monitoring
Hi,
can you please explian mehow can I monitor shared pool usage from OEM and setup threshold on it
Your help is appreciated
Thanks
You didn't mention your release, edition and if you are using Automatic Shared Memory Management(ASSM) or not.
At http://tahiti.oracle.com after choosing your release you may search for "shared pool memory advisor" Also if you are using Enterprise Edition Automatic Database Diagnostic Monitor(ADDM) will guide you if there is a shared pool specific performance need.
I hope this helps - http://download.oracle.com/docs/cd/B14117_01/server.101/b10742/montune.htm#CBBGHHJI
Best regards.
Similar Messages
-
Reducing shared pool latch contention
I see a lot of shared pool latch contention on my 11gR2 database because there are over 100 identical schemas that run identical SQL. This causes lots of child cursors to be created. Scheduled jobs kick off hourly for every schema at the same time and that produces contention for shared pool latches for the same parent cursor.
I want to reduce that contention. Here's my question...
If I make the SQL text unique by either
(a) changing the object referenbes from "TableName" to "SchemaName.TableName", or
(b) adding a comment to the SQL that includes the SchemaName
...will that cause a separate cursor to be created in the shared pool?
I know in older versions even a change in a comment would cause Oracle to treat it as a separate statement. Is that still true in 11gR2?
FWIW cursor_sharing is set to EXACT.Chuck1958 wrote:
If I make the SQL text unique by either
(a) changing the object referenbes from "TableName" to "SchemaName.TableName", or
(b) adding a comment to the SQL that includes the SchemaName
...will that cause a separate cursor to be created in the shared pool?
I know in older versions even a change in a comment would cause Oracle to treat it as a separate statement. Is that still true in 11gR2?
Yes:
SQL> select * from v$version;
BANNER
Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 - Production
PL/SQL Release 11.2.0.1.0 - Production
CORE 11.2.0.1.0 Production
TNS for Linux: Version 11.2.0.1.0 - Production
NLSRTL Version 11.2.0.1.0 - Production
SQL> show parameter cursor_sharing
NAME TYPE VALUE
cursor_sharing string EXACT
SQL> select * /* schema1 */ from t where x=0;
no rows selected
SQL> select * /* schema2 */ from t where x=0;
no rows selected
SQL> select sql_id, child_number, sql_text
2 from v$sql
3 where sql_text like '%/* schema%';
SQL_ID CHILD_NUMBER SQL_TEXT
4d03bxnvbw4ac 0 select * /* schema2 */ from t where x=0
76xtkkpvfqx1h 0 select * /* schema1 */ from t where x=0
b3zjvv0cfbhrx 0 select sql_id, child_number, sql_text fr
om v$sql where sql_text like '%/* schema
%' -
Find below a modified version of a script retrieved from Metalink 146599.1 to check for shared pool fragmentation
I am not sure if it is possible, but is there any way to incorporate into this script a query that will show the effectiveness of using an ALTER SYSTEM FLUSH SHARED_POOL command .
select bucket, freespace,
ROUND(ratio_to_report(freespace) over () * 100, 5) AS "Percentage"
from
(select '0 (<140)' BUCKET, sum(KSMCHSIZ) freespace
from x$ksmsp
where KSMCHSIZ<140
and KSMCHCLS='free'
UNION ALL
select '1 (140-267)' BUCKET, sum(KSMCHSIZ) freespace
from x$ksmsp
where KSMCHSIZ between 140 and 267
and KSMCHCLS='free'
UNION ALL
select '2 (268-523)' BUCKET, sum(KSMCHSIZ) freespace
from x$ksmsp
where KSMCHSIZ between 268 and 523
and KSMCHCLS='free'
UNION ALL
select '3-5 (524-4107)' BUCKET, sum(KSMCHSIZ) freespace
from x$ksmsp
where KSMCHSIZ between 524 and 4107
and KSMCHCLS='free'
UNION ALL
select '6+ (4108+)' BUCKET, sum(KSMCHSIZ) freespace
from x$ksmsp
where KSMCHSIZ >= 4108
and KSMCHCLS='free');Running this SQL, flushing the shared pool, and the re-running should show what the difference before and after is - or does this not suffice?
Flushing the shared pool is also not really addressing the root cause - which most often is non-sharable SQL.
Thus I'm not exactly sure what you're trying to achieve here. The SQL identifies the symptoms - flushing the shared pool treats those symptoms. For a while.
Surely you should rather be looking at the shared pool itself to determine what the problem is and try and fix that instead? A db logon trigger for a poorly written app can for example force cursor sharing for all sessions created by that app. -
Hello Team:
I ran a metalink script to report the shared pool utilization recently. I took this output when the database was on peak load.
SQL> /
Obj mem: 66435759 bytes (63.36MB)
Shared sql: 324219036 bytes (309.2MB)
Cursors: 341207073 bytes (325.4MB)
Free memory: 67228508 bytes (64.11MB)
Shared pool utilization (total): 468785754 bytes (447.07MB)
Shared pool allocation (actual): 754974720bytes (720MB)
Percentage Utilized: 91%
does this mean I have to add more space to shared pool. If so what is the threshold value?
Regards,
BalaBhawani nandan Prasad - Principal DBA -- See a to z diagnostics about Shared pool
1. Memory 2
a. Shared Pool 2
1. Introduction 2
2. Architecture 2
3. Scripts for different DBA tasks: 5
a.Measure object usage inside the shared pool and Tune shared pool 7
b.Check reload problem in library cache 12
c.Find the large queries in the shared pool library cache (using > 4mb each) 13
d.Find objects that can be considered pining into the shared pool 13
e.LRU work and objects were loaded and flushed 13
f.How much are waiting for Library Cache Latch 14
g.Queries identical but aren’t shared. 14
h.Get Biggest chunk of free memory. 14
i.Check the shared pool reserved size status 16
j.When having multiple subheaps: 16
k.Check shared pool at first glance quick diagnostics 17
l.Memory Usage - object list level view 17
m.Loads Number of times object has been loaded 17
n.Check number of times and object has been executed 18
o.Check shared pool in more details 18
p.Library Cache Statistics 18
q.Reserve Pool Settings 19
r.Pinned Objects 19
s.Finding literal SQL 19
t.Finding the Library Cache hit ratio 19
u. Row Cache Misses – Dictionary cache stats 19
v. Checking hash chain lengths 20
w. Checking for high version counts 20
x. Finding statement/s which use lots of shared pool memory 20
y. Allocations causing shared pool memory to be 'aged' out 21
z. Issues in various Oracle Releases 21
4. Terminology 22
5. Oracle 11g Caching and Pooling – SQL Result Cache 27
6. References 37
2. SQL 38
3. Statistics 38
4. Wait events 38
5. Schema 39
6. General 39
a. Scripts 39
1. accept.sql 39
1. Memory
a. Shared Pool
1. Introduction
Shared pool is used to cache different types of data such as textual and executable forms of PL/SQL blocks and SQL statements, dictionary cache data, and other data in SGA. Additional shared memory needed in the SHARED POOL if using ASM storage. Gathering schema/database stats (table/index stats) makes database query performance better and it reduce utilization of shared pool. Hence, practice to schedule job to gather stats regularly which suites your database performance. If you use shared pool effectively you can reduce resource consumption in at least four ways
1. Parse overhead is avoided if the SQL statement is already in the shared pool. This saves CPU resources on the host and elapsed time for the end user.
2. Latching resource usage is significantly reduced, which results in greater scalability.
3. Shared pool memory requirements are reduced, because all applications use the same pool of SQL statements and dictionary resources.
4. I/O resources are saved, because dictionary elements that are in the shared pool do not require disk access.
This sharable area of memory is managed as a sophisticated cache and heap manager rolled into one. It has 3 fundamental problems to overcome:
1. The unit of memory allocation is not a constant - memory allocations from the pool can be anything from a few bytes to many kilobytes
2. Not all memory can be 'freed' when a user finishes with it (as is the case in a traditional heap manager) as the aim of the shared pool is to maximize share of information. The information in the memory may be useful to another session - Oracle cannot know in advance if the items will be of any use to anyone else or not.
3. There is no disk area to page out to so this is not like a traditional cache where there is a file backing store. Only "rewriteable" information can be discarded from the cache and it has to be re-created when it is next needed.
Oracle 10g architecture of Shared pool:
Library Cache Shared SQL Area (Hash Value, SQL source, Execution plan)
Data Dictionary Cache
Enqueues Fixed Area Other
Latches
Oracle 11g architecture of Shared pool:
Library Cache Shared SQL Area (Hash Value, SQL source, Execution plan)
Data Dictionary Cache
Result Cache
Enqueues Fixed Area Other
Latches
1. Library Cache
Shared Sql Area: contains Parsed SQL and execution Plans for statements already run against the database. This area allows SQL execution plans to be reused by many users.
Private SQL Area: Private SQL areas are non-shared memory areas assigned to unique user sessions.
Pl/sql Area: contains the recently executed Procedures, Functions and Packages.
Control Structures: Common control structure information example Memory for Latches and locks, sequence cache.
2. Dictionary cache known as the row cache.
Dictionary cache stores all the metadata info of tables and views in the database, Names and data types of the columns in the database, Object and system privileges of all the Users. Oracle maintains the stats of all the objects in the shared pool, if any of the memory objects are not used from the last 3 seconds, these memory objects will be aged out and will be removed from the cache. All the Shared Pool Structures are maintained by a LRU (least recently Used) algorithm, by which Oracle removes the objects from the shared Pool, until there is enough free space in the shared Pool to keep new Object.
3. Scripts for different DBA tasks:
Dictionary Views for shared POOL:
NON-RAC
V$DB_CACHE_ADVICE
V$DB_OBJECT_CACHE
V$DLM_LATCH
V$DLM_LOCKS
V$LATCH
V$LATCHHOLDER
V$LATCHNAME
V$LATCH_CHILDREN
V$LATCH_MISSES
V$LATCH_PARENT
V$LIBRARYCACHE
V$LOCK
V$LOCKED_OBJECT
V$LOCKS_WITH_COLLISIONS
V$LOCK_ACTIVITY
V$LOCK_ELEMENT
V$OPEN_CURSOR
V$PROCESS
V$PX_PROCESS
V$PX_PROCESS_SYSSTAT
V$PX_SESSION
V$PX_SESSTAT
V$ROWCACHE
V$ROWCACHE_PARENT
V$ROWCACHE_SUBORDINATE
V$SESSION
V$SESSION_CONNECT_INFO
V$SESSION_CURSOR_CACHE
V$SESSION_EVENT
V$SESSION_LONGOPS
V$SESSION_OBJECT_CACHE
V$SESSION_WAIT
V$SESSTAT
V$SESS_IO
V$SGA
V$SGASTAT
V$SGAINFO
V$SGA_DYAMIC_COMPONENTS
V$SGA_DYNAMIC_FREE_MEMORY
V$SGA_RESIZE_OPS
V$SGA_CURRENT_RESIZE_OPS
v$shared_pool_advice
V_$SHARED_POOL_ADVICE
V$SHARED_POOL_RESERVED
V$SHARED_SERVER
V$SORT_SEGMENT
V$SORT_USAGE
V$SQL
V$SQLAREA
V$SQLTEXT
V$SQLTEXT_WITH_NEWLINES
V$SQL_BIND_DATA
V$SQL_BIND_METADATA
V$SQL_CURSOR
V$SQL_SHARED_CURSOR
V$SQL_SHARED_MEMORY
V$STATNAME
V$SUBCACHE
V$SYSSTAT
V$SYSTEM_CURSOR_CACHE
V$SYSTEM_EVENT
V$SYSTEM_PARAMETER
X$KSMSP
RAC
GV$LATCH
GV$LATCHHOLDER
GV$LATCHNAME
GV$LATCH_CHILDREN
GV$LATCH_MISSES
GV$LATCH_PARENT
GV$LIBRARYCACHE
GV$LOCK
GV$LOCKED_OBJECT
GV$LOCKS_WITH_COLLISIONS
GV$LOCK_ACTIVITY
GV$LOCK_ELEMENT
GV$PROCESS
GV$PX_PROCESS
GV$PX_PROCESS_SYSSTAT
GV$PX_SESSION
GV$PX_SESSTAT
GV$ROWCACHE
GV$ROWCACHE_PARENT
GV$ROWCACHE_SUBORDINATE
GV$SESSION
GV$SESSION_CONNECT_INFO
GV$SESSION_CURSOR_CACHE
GV$SESSION_EVENT
GV$SESSION_LONGOPS
GV$SESSION_OBJECT_CACHE
GV$SESSION_WAIT
GV$SESSTAT
GV$SESS_IO
GV$SGA
GV$SGASTAT
gv$shared_pool_advice
GV$SHARED_POOL_RESERVED
GV$SHARED_SERVER
GV$SORT_SEGMENT
GV$SORT_USAGE
GV$SQL
GV$SQLAREA
GV$SQLTEXT
GV$SQLTEXT_WITH_NEWLINES
GV$SQL_BIND_DATA
GV$SQL_BIND_METADATA
GV$SQL_CURSOR
GV$SQL_SHARED_CURSOR
GV$SQL_SHARED_MEMORY
GV$STATNAME
GV$SUBCACHE
GV$SYSSTAT
GV$SYSTEM_CURSOR_CACHE
GV$SYSTEM_EVENT
GV$SYSTEM_PARAMETER
GV$WAITSTAT
GV$_LOCK
a.Measure object usage inside the shared pool and Tune shared pool
set pagesize 132
column owner format a16
column name format a36
column sharable_mem format 999,999,999
column executions format 999,999,999
prompt
prompt Memory Usage of Shared Pool Order - Biggest First
prompt
column name format 45
select owner, name||' - '||type name, sharable_mem from v$db_object_cache
where sharable_mem > 10000
and type in ('PACKAGE', 'PACKAGE BODY', 'FUNCTION', 'PROCEDURE')
order by sharable_mem desc
prompt
prompt Loads into Shared Pool - Most Loads First
prompt
select owner, name||' - '||type name, loads , sharable_mem from v$db_object_cache
where loads > 3
and type in ('PACKAGE', 'PACKAGE BODY', 'FUNCTION', 'PROCEDURE')
order by loads desc
prompt
prompt Executions of Objects in the Shared Pool - Most Executions First
prompt
select owner, name||' - '||type name, executions from v$db_object_cache
where executions > 100
and type in ('PACKAGE', 'PACKAGE BODY', 'FUNCTION', 'PROCEDURE')
order by executions desc
select 'If the values for the EXEC and LOADS close increase SHARED_POOL_SIZE!' from dual ;
set feedback off
set linesize 80
set pagesize 52
clear columns
clear breaks
col executions HEADING EXEC
col sharable_mem heading SHAMEM
col owner format a8
col name format a30
col type format a12
set numwidth 8
ttitle center 'Data Base Objects Owned by All Users Statistics' skip 2
select name, type, sharable_mem, loads, executions, pins
from sys.v_$db_object_cache ;
b.Check reload problem in library cache
select namespace, pins, reloads from v$librarycache;
show parameters shared_pool
select bytes/1024/1024 from v$sgastat where pool='shared pool' and name='free memory';
c.Find the large queries in the shared pool library cache (using > 4mb each)
SELECT sql_text "Stmt", count(*), sum(sharable_mem) "Mem",
sum(users_opening) "Open", sum(executions) "Exec"
FROM v$sql GROUP BY sql_text HAVING sum(sharable_mem) > 4096000;
d.Find objects that can be considered pining into the shared pool
column name format a40
column owner format a15
select owner, name, executions, locks, pins, loads, kept from v$db_object_cache where loads > 10;
create temp table and insert records of candidates to be pinned.
CREATE TABLE LRU_TMP AS SELECT * FROM X$KSMLRU;
INSERT INTO LRU_TMP SELECT * FROM X$KSMLRU;
Use the LRU_TMP table for analysis.
SELECT USERNAME, KSMLRCOM, KSMLRHON, KSMLRNUM, KSMLRSIZ, SQL_TEXT
FROM V$SQLAREA A, LRU_TMP K, V$SESSION S WHERE KSMLRSIZ > 3000
AND A.ADDRESS=S.SQL_ADDRESS AND A.HASH_VALUE = S.SQL_HASH_VALUE
AND SADDR=KSMLRSES;
You can see the candidates to pin from the query below
COL STORED_OBJECT FORMAT A40;
COL SQ_EXECUTIONS FORMAT 999,999;
SELECT /*+ ORDERED USE_HASH(D) USE_HASH(C) */ O.KGLNAOWN||’.'||O.KGLNAOBJ STORED_OBJECT, SUM(C.KGLHDEXC) SQL_EXECUTIONS
FROM SYS.X$KGLOB O, SYS.X$KGLRD D, SYS.X$KGLCURSOR C
WHERE
O.INST_ID = USERENV(’INSTANCE’) AND
D.INST_ID = USERENV(’INSTANCE’) AND
C.INST_ID = USERENV(’INSTANCE’) AND
O.KGLOBTYP IN (7, 8, 9, 11, 12) AND
D.KGLHDCDR = O.KGLHDADR AND
C.KGLHDPAR = D.KGLRDHDL
GROUP BY O.KGLNAOWN, O.KGLNAOBJ
HAVING SUM(C.KGLHDEXC) > 0
ORDER BY 2 DESC;
How to pin object
EXECUTE SYS.DBMS_SHARED_POOL.SIZES(150);
EXECUTE SYS.DBMS_SHARED_POOL.KEEP('SYS.STANDARD');
EXECUTE SYS.DBMS_SHARED_POOL.UNKEEP('SYS.STANDARD');
e.LRU work and objects were loaded and flushed
LRU work in the shared pool KSMLRNUM stores the number of objects that were flushed to load the large object. KSMLRISZ stores the size of the object that was loaded (contiguous memory allocated)
column ksmlrcom format a20
column username format a5
select username,sid,KSMLRCOM,KSMLRSIZ,KSMLRNUM, KSMLRHON, KSMLROHV, KSMLRSES from x$ksmlru , v$session where KSMLRSES=SADDR and KSMLRNUM >2 ;
f.How much are waiting for Library Cache Latch
select count(*),event from v$session_wait where event not like '%SQL%' and event not like '%ipc%' and event not like '%timer%' GROUP BY EVENT;
select count(*),wait_time from v$session_wait where event='latch free' and p2=106 group by wait_time;
select sid,wait_time,seconds_in_wait from v$session_wait where event='latch free' and p2=106 and WAIT_TIME>1;
g.Queries identical but aren’t shared.
SELECT address, hash_value, version_count , users_opening , users_executing,
substr(sql_text,1,240) "SQL" FROM v$sqlarea WHERE version_count > 10;
h.Get Biggest chunk of free memory.
select sysdate, decode( sign(ksmchsiz - 812), -1, (ksmchsiz - 16) / 4,
decode(sign(ksmchsiz - 4012),-1, trunc((ksmchsiz + 11924) / 64),
decode(sign(ksmchsiz - 65548), -1, trunc(1/log(ksmchsiz - 11, 2)) + 238,254))) bucket,
sum(ksmchsiz) free_space, count(*) free_chunks, trunc(avg(ksmchsiz)) average_size,
max(ksmchsiz) biggest from x$ksmsp
where inst_id = userenv('Instance') and ksmchcls = 'free' group by
decode(sign(ksmchsiz - 812),-1, (ksmchsiz - 16) / 4,
decode(sign(ksmchsiz - 4012),-1, trunc((ksmchsiz + 11924) / 64),
decode(sign(ksmchsiz - 65548),-1, trunc(1/log(ksmchsiz - 11, 2)) + 238,254 ))) ;
SELECT KSMCHCLS CLASS, COUNT(KSMCHCLS) NUM, SUM(KSMCHSIZ) SIZ,
To_char( ((SUM(KSMCHSIZ)/COUNT(KSMCHCLS)/1024)),’999,999.00′)||’k’ “AVG SIZE”
FROM X$KSMSP GROUP BY KSMCHCLS;
CLASS NUM SIZ AVG SIZE
freeabl 19010 34519404 1.77k
recr 23581 24967956 1.03k
R-freea 68 1632 .02k
perm 22 39801268 1,766.75k
R-free 34 7238192 207.90k
free 2389 36075980 14.75k
Watch for trends using these guidelines:
a) if ‘free’ memory is low (less than 5mb or so) you may need to increase the shared_pool_size and shared_pool_reserved_size. You should expect ‘free’ memory to increase and decrease over time. Seeing trends where ‘free’ memory decreases consistently is not necessarily a problem, but seeing consistent spikes up and down could be a problem.
b) if ‘freeable’ or ‘perm’ memory continually grows then it is possible you are seeing a memory bug.
c) if ‘freeabl’ and ‘recr’ memory classes are always huge, this indicates that you have a lot of cursor info stored that is not releasing.
d) if ‘free’ memory is huge but you are still getting 4031 errors, the problem is likely reloads and invalids in the library cache causing fragmentation.
-Note says that this query can hang database on HP platforms
See the shared pool parameters
column name format a30
select name,value from v$parameter where name like '%shared_pool%' ;
select x.ksppinm, y.ksppstvl from x$ksppi x , x$ksppcv y where x.indx = y.indx and lower(x.ksppinm) like '%spin%';
SELECT count(*) FROM v$latch_children WHERE NAME = 'library cache';
Shrinking and growing operations from V$SGA_RESIZE_OPS dynamic view:
select to_char(end_time, ‘dd-Mon-yyyy hh24:mi’) end, oper_type, initial_size, target_size, final_size from V$SGA_RESIZE_OPS where component=’shared pool’ order by end;
#shared_pool_summary.sql -get an overview of chunks in the shared pool
select
ksmchcom contents,
count(*) chunks,
sum(decode(ksmchcls, 'recr', ksmchsiz)) recreatable,
sum(decode(ksmchcls, 'freeabl', ksmchsiz)) freeable,
sum(ksmchsiz) total
from
sys.x_$ksmsp
where
inst_id = userenv('Instance') and
ksmchcls not like 'R%'
group by
ksmchcom
#reserved_pool_summary.sql - get an overview of chunks in the reserved pool
select
ksmchcom contents,
count(*) chunks,
sum(decode(ksmchcls, 'R-recr', ksmchsiz)) recreatable,
sum(decode(ksmchcls, 'R-freea', ksmchsiz)) freeable,
sum(ksmchsiz) total
from
sys.x_$ksmspr
where
inst_id = userenv('Instance')
group by
ksmchcom
#save_sqlplus_settings.sql -reset sqlplus settings
set termout off
store set sqlplus_settings replace
clear breaks
clear columns
clear computes
set feedback off
set verify off
set termout on
set define "&"
#restore_sqlplus_settings.sql -reset sqlplus settings
set termout off
@sqlplus_settings
clear breaks
clear columns
clear computes
set termout on
i.Check the shared pool reserved size status
SELECT free_space, avg_free_size, used_space, avg_used_size, REQUEST_MISSES, request_failures, last_miss_size FROM v$shared_pool_reserved;
An ORA-04031 error referencing large failed requests, indicates the Reserved Area is too fragmented. The reserved pool is small when: REQUEST_FAILURES > 0 (and increasing), The DBA should Increase shared_pool_reserved_size and shared_pool_size together. It is possible that too much memory has been allocated to the reserved list. The DBA should Decrease shared_pool_reserved_size, If: REQUEST_MISS = 0 or not increasing
FREE_MEMORY = > 50% of shared_pool_reserved_size minimum
col free_space for 999,999,999,999 head “TOTAL FREE”
col avg_free_size for 999,999,999,999 head “AVERAGE|CHUNK SIZE
col free_count for 999,999,999,999 head “COUNT”
col request_misses for 999,999,999,999 head “REQUEST|MISSES
col request_failures for 999,999,999,999 head “REQUEST|FAILURES”
col max_free_size for 999,999,999,999 head “LARGEST CHUNK”
select free_space, avg_free_size, free_count, max_free_size, request_misses, request_failures from v$shared_pool_reserved;
TOTAL FREE AVERAGE
CHUNK SIZE COUNT LARGEST CHUNK REQUEST
MISSES REQUEST
FAILURES
7,238,192 212,888 34 212,888 0 0
You should also use hidden and unsupported parameter “_shared_pool_reserved_pct” to control reserved pool. This parameter controls the allocated percentage of shared pool for reserved pool. By default it is %5 of the shared pool and if you use ASMM for memory management you can set this value higher like 10 to allocate reserved pool dynamically. When you set the parameter you will see the shared_pool_reserved_size parameter will be adjusted to the new setting. The parameter can not be modified when instance is started. You can use the query below to see the current value
select a.ksppinm “Parameter”, b.ksppstvl “Session Value”, c.ksppstvl “Instance Value” from sys.x$ksppi a, sys.x$ksppcv b, sys.x$ksppsv c where a.indx = b.indx and a.indx = c.indx and a.ksppinm = ‘_shared_pool_reserved_pct’;
Parameter Session Value Instance Value
sharedpool_reserved_pct 10 10
j.When having multiple subheaps:
select KSMCHIDX, ksmchcom ChunkComment,
decode(round(ksmchsiz/1000),0,'0-1K', 1,'1-2K', 2,'2-3K', 3,'3-4K',4,'4-5K',5,'5-6k',6,'6-7k',7,'7-8k',8,'8-9k', 9,'9-10k', '> 10K'), count(*), ksmchcls Status, sum(ksmchsiz) Bytes
from x$ksmsp where KSMCHCOM = 'free memory' group by KSMCHIDX,ksmchcom, ksmchcls, decode(round(ksmchsiz/1000),0,'0-1K', 1,'1-2K', 2,'2-3K', 3,'3-4K',4,'4-5K',5,'5-6k',6,'6-7k',7,'7-8k',8,'8-9k', 9,'9-10k','> 10K');
SubPool SGA_HEAP CHUNKCOMMENT size COUNT(*) STATUS BYTES
1 sga heap(1,0) free memory > 10K 34 R-free 7238192
1 sga heap(1,0) free memory 3-4K 2 free 6284
1 sga heap(1,0) free memory > 10K 241 free 35707400
1 sga heap(1,0) free memory 8-9k 1 free 7712
1 sga heap(1,0) free memory 2-3K 4 free 6752
1 sga heap(1,0) free memory 0-1K 2090 free 133288
1 sga heap(1,0) free memory 9-10k 21 free 188676
1 sga heap(1,0) free memory 1-2K 30 free 25868
If you see lack of large chunks it is possible that you can face with ORA-04031 in near future.
k.Check shared pool at first glance quick diagnostics
select 'You may need to increase the SHARED_POOL_RESERVED_SIZE' Description, 'Request Failures = '||REQUEST_FAILURES Logic
from v$shared_pool_reserved where REQUEST_FAILURES > 0
and 0 != (select to_number(VALUE) from v$parameter
where NAME = 'shared_pool_reserved_size')
union
select 'You may be able to decrease the SHARED_POOL_RESERVED_SIZE' Description,'Request Failures = '||REQUEST_FAILURES Logic
from v$shared_pool_reserved where REQUEST_FAILURES < 5
and 0 != (select to_number(VALUE) from v$parameter
where NAME = 'shared_pool_reserved_size')
l.Memory Usage - object list level view
• Owner - Owner of the object
• Object - Name/namespace of the object
• Sharable Memory - Amount of sharable memory in the shared pool consumed by the object
select OWNER, NAME||' - '||TYPE object,SHARABLE_MEM
from v$db_object_cache where SHARABLE_MEM > 10000
and type in ('PACKAGE','PACKAGE BODY','FUNCTION','PROCEDURE')
order by owner asc ,SHARABLE_MEM desc
SELECT * FROM (SELECT ROW_NUMBER () over (PARTITION BY NAMESPACE ORDER BY SHARABLE_MEM DESC) ROW_within , NAMESPACE, SHARABLE_MEM, SUBSTR(NAME,1,40) NAME FROM V$DB_OBJECT_CACHE ORDER BY SHARABLE_MEM DESC) WHERE ROW_WITHIN <= 2 ORDER BY NAMESPACE, ROW_WITHIN;
ROW_WITHIN NAMESPACE SHARABLE_MEM NAME
1 CLUSTER 2794 C_OBJ#_INTCOL#
2 CLUSTER 1684 SMON_SCN_TO_TIME
1 RSRCPLAN 5117 SYS_GROUP -
Increase Shared Pool for erorr # ORA-04031
hi,
what do i need to look at before i increase the shared pool of our database?
there is just the one database instance on the machine.
i am concerned about the repurcussions on the server.
i hope the information below is of help.
db version: 10.2.0.1.0
os: Red Hat Linux 3
SQL> select name, value from v$parameter where name like '%pool%';
name value
shared_pool_size 150994944
large_pool_size 33554432
java_pool_size 50331648
streams_pool_size 0
shared_pool_reserved_size 10066329
buffer_pool_keep
buffer_pool_recycle
global_context_pool_size
olap_page_pool_size 0
thanks,
santosh sewlalHi Santosh,
This is what i faced last two days back! Now i am monitoring the Issue! If you got any solutions please let me know how to avoid this!
ORA-04031 error can be due to either an inadequeate sizing of the SHARED POOL size or due to heavy
fragmentation leading the database to not finding large enough chuncks of memory.
You can monitor this with the two events...
alter system set events '4031 trace name errorstack level 3';
alter system set events '4031 trace name heapdump level 3';
Fragmentataion is one of the causes of ora 4031
Please refer these.
1.Article-ID: Note 146599.1
Title: Diagnosing and Resolving Error ORA-04031
2.Article-ID: Note 62143.1
Title: Understanding and Tuning the Shared Pool
3.Article-ID: Note 61623.1
This is paticular for Oracle 9i Rel 2, Hope the same for Oracle 10 G
Regards
Ravi -
Contention for latches related to the shared pool was consuming significant
We are having performance issue on our database. When I look at the AWR, I see that there is a contention for latches. Below is the AWR Report.
ADDM Report for Task 'ADDM:1775307360_12808'
Analysis Period
AWR snapshot range from 12807 to 12808.
Time period starts at 10-MAY-11 01.00.15 PM
Time period ends at 10-MAY-11 02.00.23 PM
Analysis Target
Database 'ADVFDWP' with DB ID 1775307360.
Database version 11.1.0.7.0.
ADDM performed an analysis of all instances.
Activity During the Analysis Period
Total database time was 27827 seconds.
The average number of active sessions was 7.71.
Summary of Findings
Description Active Sessions Recommendations
Percent of Activity
1 Shared Pool Latches 6.43 | 83.42 0
2 Top SQL by DB Time 2.41 | 31.24 3
3 "Concurrency" Wait Class 2.18 | 28.22 0
4 PL/SQL Execution 1.53 | 19.86 1
5 "User I/O" wait Class 1.33 | 17.24 0
6 Hard Parse 1.24 | 16.14 0
7 Undersized Buffer Cache .83 | 10.73 0
8 CPU Usage .7 | 9.02 0
9 Top SQL By I/O .31 | 4.04 1
10 Top Segments by I/O .24 | 3.12 1
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Findings and Recommendations
Finding 1: Shared Pool Latches
Impact is 6.43 active sessions, 83.42% of total activity.
Contention for latches related to the shared pool was consuming significant
database time in some instances.
Instances that were significantly affected by this finding:
Number Name Percent Impact ADDM Task Name
1 ADVFDWP1 99.31 ADDM:1775307360_1_12808
Check the ADDM analysis of affected instances for recommendations.
Finding 2: Top SQL by DB Time
Impact is 2.41 active sessions, 31.24% of total activity.
SQL statements consuming significant database time were found.
Recommendation 1: SQL Tuning
Estimated benefit is 1.07 active sessions, 13.82% of total activity.
Action
Run SQL Tuning Advisor on the SQL statement with SQL_ID "fdk73nhpt93a5".
Related Object
SQL statement with SQL_ID fdk73nhpt93a5.
INSERT INTO SFCDM.F_LOAN_PTFL_MOL_SNPSHT SELECT * FROM
F_LOAN_PTFL_MOL_SNPSHT_STG
Recommendation 2: SQL Tuning
Estimated benefit is 1 active sessions, 12.96% of total activity.
Action
Tune the PL/SQL block with SQL_ID "7nvgzsgy9ydn9". Refer to the "Tuning
PL/SQL Applications" chapter of Oracle's "PL/SQL User's Guide and
Reference".
Related Object
SQL statement with SQL_ID 7nvgzsgy9ydn9.
begin
insert into SFCDM.F_LOAN_PTFL_MOL_SNPSHT select * from
F_LOAN_PTFL_MOL_SNPSHT_STG;
end;
Recommendation 3: SQL Tuning
Estimated benefit is .4 active sessions, 5.2% of total activity.
Action
Investigate the SQL statement with SQL_ID "fcvfq2gzmxu0t" for possible
performance improvements.
Related Object
SQL statement with SQL_ID fcvfq2gzmxu0t.
select
a11.DT_YR_MO DT_YR_MO,
a11.IND_SCRTZD IND_SCRTZD,
a13.CD_LNSTAT CD_LNSTAT_INTGRTD,
sum(a11.CNT_LOAN) WJXBFS1,
sum(a11.AMT_PART_EOP_UPB) WJXBFS2,
sum(a11.AMT_LST_VLD_PART_UPB) WJXBFS3
from
SFCDM.F_LOAN_PTFL_MOL_SNPSHT
a11
join
SFCDM.D_DETD_LNSTAT_CURR
a12
on
(a11.ID_CYCL_CLOS_DETD_LNSTAT_SRGT = a12.ID_DETD_LNSTAT_SRGT)
join
SFCDM.D_LNSTAT_CD
a13
on
(a12.ID_LNSTAT_CD_SRGT = a13.ID_LNSTAT_CD_SRGT)
join
SFCDM.D_LOAN_CHARTC_CURR_MINI
a14
on
(a11.ID_LOAN_CHARTC_SRGT = a14.ID_LOAN_CHARTC_SRGT)
where
(a11.DT_YR_MO in (201103)
and a14.CD_SFCRM_LOAN_BUS_LI not in ('L', 'T', 'W')
and a13.CD_LNSTAT in (14)
and not exists
(select * from SFCDM.F_LOAN_PTFL_MOL_SNPSHT s
where s.id_loan_syst_gend = a11.id_loan_syst_gend
and s.dt_yr_moIt is worth checking the actual size of the shared pool e.g.
select pool,sum(bytes)/1024/1024/1024 from v$sgastat group by pool;
the parameters you ahve posted suggest you have set a minimum but no maximum, so it could very large.
Next up is looking for unhared SQL i.e.
select column1 from some_table where column2='A_VALUE';
select column1 from some_table where column2='Another_Value';
where the code should be using binds instead of literals for security and performance reasons, a simple way to find this is to look in v$sql for sql having the same plan_hash_value but different sql_Ids and compare the sql_fulltext of each statement.
Also a possibility is sql with many child cursors, this is trickier as the cause may vary and may not be easy to fix. check th econtents of v$sql for sql that have high values in the child_number column anmd investigate the contents of v$sql_shared_cursor for the reason there are multiple child cursors.
Chris -
Keep Sequences in Shared Pool for RAC Environment
Hi,
We have 2 node RAC setup for production environment. I want to pin cached sequences in my database. We are using following command for this purpose.
EXEC DBMS_SHARED_POOL.KEEP('HR.MySeq','Q');
Do I need to execute this command for each single node?Pinning is in the Shared Pool in the SGA. So it is local to an instance.
Therefore, you would need to execute it in each instance (i.e. on each node).
Note : However, with sequences in RAC, you have to be careful with the definition. Have you defined it or do you need to define it as CACHE/NOCACHE ? Have you defined it or do you need to define it as ORDER (to guarantee order generation in RAC) ?
Hemant K Chitale -
% shared pool free problem in OEM database health
can u tell me what to do when the %shared pool free falls below 1% ..
what can be the solution.
if it is in the form of changing the shared pool size, how are the calculations done (in detail)?
other two parameters have values 99.99% and 98.95(buffer cache hit % and library cache hit %)user630185,
First look at things the other way round - if you have free memory in the shared pool, that means you have memory you are not using, why do you want to increase the amount of memory you are not using ?
Unless you can see a performance problem relating to a memory shortfall in the shared pool then you don't need to increase it. In fact, you could find that you introduce performance problems by increasing the shared pool if you are not making good use of shared SQL throughout your system.
Check for things like time lost on library and shared pool latches, CPU spent on parsing and "hard" parsing, successful use of the session cursor cache before worrying about the 1% free.
Regards
Jonathan Lewis
http://jonathanlewis.wordpress.com
http://www.jlcomp.demon.co.uk -
How to pin sequences in the shared pool for RAC?
We have a RAC environment with two instances. I want to pin some sequences in the shared pool to boost the performance. Do I need to pin them in both of the instances or just pin them in one instance?
Thanks in advanceIf you cannot tolerate gaps, you must not use sequences. Period. A sequence-generated key will have gaps because transactions roll back, because databases get shut down, etc. If you want to ensure that there are no gaps, you have to write code that serializes access to a resource (i.e. a custom table of sequences) over the full length of a transaction. Of course, this is hugely inefficient and kills the application's scalability, but it does prevent gaps. Sequences are much faster and much more scalable, but they do not and can not guarantee that there are no gaps.
Assuming the intention is to minimize gaps, rather than to eliminate them, NOCACHE & ORDER can help. That means, though, that you may need to communicate with the other nodes in the cluster every time you need a new value from the sequence, which is the slow part. Pinning the sequence is not going to be beneficial.
Justin -
Hi,
In recent we are getting shared pool exhaust issue. I am interested to know which objects occupying more share pool.Do we have any queries which can show the most space occupied objects in shared pool
do we have any monitoring tools(or queries) using which we can findout once shared pool usage has gone to 70%.I guess OEM automatically alert this if we confgiure it for
I heard that "alter system flush share_pool" doesn't work properly.there is bug in that.After executing this also it wont release shared pool.Is it true ??
Thanks for your information.
Thanks
AnandIn recent we are getting shared pool exhaust issue. I am interested to know which objects occupying more share pool.Do we have any queries which can show the most space occupied objects in shared poolThis if V$DB_OBJECT_CACHE helps for this.
I heard that "alter system flush share_pool" doesn't work properly.there is bug in that.After executing this also it wont release shared pool.Is it true ??Not sure about the bug, do you have the bug number handy. Also, what do you mean by - "it wont release shared pool"...it doesn't release the entire memory allocated to shared pool.
Thanks
Chandra -
How to set the correct shared pool size and db_buffer_cache using awr
Hi All,
I want to how to set the correct size for shared_pool_size and db_cache_size using shared pool advisory and buffer pool advisory of awr report. I have paste the shared and buffer pool advisory of awr report.
Shared Pool Advisory
* SP: Shared Pool Est LC: Estimated Library Cache Factr: Factor
* Note there is often a 1:Many correlation between a single logical object in the Library Cache, and the physical number of memory objects associated with it. Therefore comparing the number of Lib Cache objects (e.g. in v$librarycache), with the number of Lib Cache Memory Objects is invalid.
Shared Pool Size(M) SP Size Factr Est LC Size (M) Est LC Mem Obj Est LC Time Saved (s) Est LC Time Saved Factr Est LC Load Time (s) Est LC Load Time Factr Est LC Mem Obj Hits (K)
4,096 1.00 471 25,153 184,206 1.00 149 1.00 9,069
4,736 1.16 511 27,328 184,206 1.00 149 1.00 9,766
5,248 1.28 511 27,346 184,206 1.00 149 1.00 9,766
5,760 1.41 511 27,346 184,206 1.00 149 1.00 9,766
6,272 1.53 511 27,346 184,206 1.00 149 1.00 9,766
6,784 1.66 511 27,346 184,206 1.00 149 1.00 9,766
7,296 1.78 511 27,346 184,206 1.00 149 1.00 9,766
7,808 1.91 511 27,346 184,206 1.00 149 1.00 9,766
8,320 2.03 511 27,346 184,206 1.00 149 1.00 9,766
Buffer Pool Advisory
* Only rows with estimated physical reads >0 are displayed
* ordered by Block Size, Buffers For Estimate
P Size for Est (M) Size Factor Buffers (thousands) Est Phys Read Factor Estimated Phys Reads (thousands) Est Phys Read Time Est %DBtime for Rds
D 4,096 0.10 485 1.02 1,002 1 0.00
D 8,192 0.20 970 1.00 987 1 0.00
D 12,288 0.30 1,454 1.00 987 1 0.00
D 16,384 0.40 1,939 1.00 987 1 0.00
D 20,480 0.50 2,424 1.00 987 1 0.00
D 24,576 0.60 2,909 1.00 987 1 0.00
D 28,672 0.70 3,394 1.00 987 1 0.00
D 32,768 0.80 3,878 1.00 987 1 0.00
D 36,864 0.90 4,363 1.00 987 1 0.00
D 40,960 1.00 4,848 1.00 987 1 0.00
D 45,056 1.10 5,333 1.00 987 1 0.00
D 49,152 1.20 5,818 1.00 987 1 0.00
D 53,248 1.30 6,302 1.00 987 1 0.00
D 57,344 1.40 6,787 1.00 987 1 0.00
D 61,440 1.50 7,272 1.00 987 1 0.00
D 65,536 1.60 7,757 1.00 987 1 0.00
D 69,632 1.70 8,242 1.00 987 1 0.00
D 73,728 1.80 8,726 1.00 987 1 0.00
D 77,824 1.90 9,211 1.00 987 1 0.00
D 81,920 2.00 9,696 1.00 987 1 0.00
My shared pool size is 4gb and db_cache_size is 40Gb.
Please help me in configuring the correct size for this.
Thanks and Regards,Hi ,
Actually batch load is taking too much time.
Please find below the 1 hr awr report
Snap Id Snap Time Sessions Cursors/Session
Begin Snap: 6557 27-Nov-11 16:00:06 126 1.3
End Snap: 6558 27-Nov-11 17:00:17 130 1.6
Elapsed: 60.17 (mins)
DB Time: 34.00 (mins)
Report Summary
Cache Sizes
Begin End
Buffer Cache: 40,960M 40,960M Std Block Size: 8K
Shared Pool Size: 4,096M 4,096M Log Buffer: 25,908K
Load Profile
Per Second Per Transaction Per Exec Per Call
DB Time(s): 0.6 1.4 0.00 0.07
DB CPU(s): 0.5 1.2 0.00 0.06
Redo size: 281,296.9 698,483.4
Logical reads: 20,545.6 51,016.4
Block changes: 1,879.5 4,667.0
Physical reads: 123.7 307.2
Physical writes: 66.4 164.8
User calls: 8.2 20.4
Parses: 309.4 768.4
Hard parses: 8.5 21.2
W/A MB processed: 1.7 4.3
Logons: 0.7 1.6
Executes: 1,235.9 3,068.7
Rollbacks: 0.0 0.0
Transactions: 0.4
Instance Efficiency Percentages (Target 100%)
Buffer Nowait %: 100.00 Redo NoWait %: 100.00
Buffer Hit %: 99.66 In-memory Sort %: 100.00
Library Hit %: 99.19 Soft Parse %: 97.25
Execute to Parse %: 74.96 Latch Hit %: 99.97
Parse CPU to Parse Elapsd %: 92.41 % Non-Parse CPU: 98.65
Shared Pool Statistics
Begin End
Memory Usage %: 80.33 82.01
% SQL with executions>1: 90.90 86.48
% Memory for SQL w/exec>1: 90.10 86.89
Top 5 Timed Foreground Events
Event Waits Time(s) Avg wait (ms) % DB time Wait Class
DB CPU 1,789 87.72
db file sequential read 27,531 50 2 2.45 User I/O
db file scattered read 26,322 30 1 1.47 User I/O
row cache lock 1,798 20 11 0.96 Concurrency
OJVM: Generic 36 15 421 0.74 Other
Host CPU (CPUs: 24 Cores: 12 Sockets: )
Load Average Begin Load Average End %User %System %WIO %Idle
0.58 1.50 2.8 0.7 0.1 96.6
Instance CPU
%Total CPU %Busy CPU %DB time waiting for CPU (Resource Manager)
2.2 63.6 0.0
Memory Statistics
Begin End
Host Mem (MB): 131,072.0 131,072.0
SGA use (MB): 50,971.4 50,971.4
PGA use (MB): 545.5 1,066.3
% Host Mem used for SGA+PGA: 39.30 39.70
RAC Statistics
Begin End
Number of Instances: 2 2
Global Cache Load Profile
Per Second Per Transaction
Global Cache blocks received: 3.09 7.68
Global Cache blocks served: 1.86 4.62
GCS/GES messages received: 78.64 195.27
GCS/GES messages sent: 53.82 133.65
DBWR Fusion writes: 0.52 1.30
Estd Interconnect traffic (KB) 65.50
Global Cache Efficiency Percentages (Target local+remote 100%)
Buffer access - local cache %: 99.65
Buffer access - remote cache %: 0.02
Buffer access - disk %: 0.34
Global Cache and Enqueue Services - Workload Characteristics
Avg global enqueue get time (ms): 0.0
Avg global cache cr block receive time (ms): 1.7
Avg global cache current block receive time (ms): 1.0
Avg global cache cr block build time (ms): 0.0
Avg global cache cr block send time (ms): 0.0
Global cache log flushes for cr blocks served %: 1.4
Avg global cache cr block flush time (ms): 0.9
Avg global cache current block pin time (ms): 0.0
Avg global cache current block send time (ms): 0.0
Global cache log flushes for current blocks served %: 0.1
Avg global cache current block flush time (ms): 0.0
Global Cache and Enqueue Services - Messaging Statistics
Avg message sent queue time (ms): 0.0
Avg message sent queue time on ksxp (ms): 0.4
Avg message received queue time (ms): 0.5
Avg GCS message process time (ms): 0.0
Avg GES message process time (ms): 0.0
% of direct sent messages: 79.13
% of indirect sent messages: 17.10
% of flow controlled messages: 3.77
Cluster Interconnect
Begin End
Interface IP Address Pub Source IP Pub Src
en9 10.51.10.61 N Oracle Cluster Repository
Main Report
* Report Summary
* Wait Events Statistics
* SQL Statistics
* Instance Activity Statistics
* IO Stats
* Buffer Pool Statistics
* Advisory Statistics
* Wait Statistics
* Undo Statistics
* Latch Statistics
* Segment Statistics
* Dictionary Cache Statistics
* Library Cache Statistics
* Memory Statistics
* Streams Statistics
* Resource Limit Statistics
* Shared Server Statistics
* init.ora Parameters
More RAC Statistics
* RAC Report Summary
* Global Messaging Statistics
* Global CR Served Stats
* Global CURRENT Served Stats
* Global Cache Transfer Stats
* Interconnect Stats
* Dynamic Remastering Statistics
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Statistic Name Time (s) % of DB Time
sql execute elapsed time 1,925.20 94.38
DB CPU 1,789.38 87.72
connection management call elapsed time 99.65 4.89
PL/SQL execution elapsed time 89.81 4.40
parse time elapsed 46.32 2.27
hard parse elapsed time 25.01 1.23
Java execution elapsed time 21.24 1.04
PL/SQL compilation elapsed time 11.92 0.58
failed parse elapsed time 9.37 0.46
hard parse (sharing criteria) elapsed time 8.71 0.43
sequence load elapsed time 0.06 0.00
repeated bind elapsed time 0.02 0.00
hard parse (bind mismatch) elapsed time 0.01 0.00
DB time 2,039.77
background elapsed time 122.00
background cpu time 113.42
Statistic Value End Value
NUM_LCPUS 0
NUM_VCPUS 0
AVG_BUSY_TIME 12,339
AVG_IDLE_TIME 348,838
AVG_IOWAIT_TIME 221
AVG_SYS_TIME 2,274
AVG_USER_TIME 9,944
BUSY_TIME 299,090
IDLE_TIME 8,375,051
IOWAIT_TIME 6,820
SYS_TIME 57,512
USER_TIME 241,578
LOAD 1 2
OS_CPU_WAIT_TIME 312,200
PHYSICAL_MEMORY_BYTES 137,438,953,472
NUM_CPUS 24
NUM_CPU_CORES 12
GLOBAL_RECEIVE_SIZE_MAX 1,310,720
GLOBAL_SEND_SIZE_MAX 1,310,720
TCP_RECEIVE_SIZE_DEFAULT 16,384
TCP_RECEIVE_SIZE_MAX 9,223,372,036,854,775,807
TCP_RECEIVE_SIZE_MIN 4,096
TCP_SEND_SIZE_DEFAULT 16,384
TCP_SEND_SIZE_MAX 9,223,372,036,854,775,807
TCP_SEND_SIZE_MIN 4,096
Back to Wait Events Statistics
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Operating System Statistics - Detail
Snap Time Load %busy %user %sys %idle %iowait
27-Nov 16:00:06 0.58
27-Nov 17:00:17 1.50 3.45 2.79 0.66 96.55 0.08
Back to Wait Events Statistics
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Foreground Wait Class
* s - second, ms - millisecond - 1000th of a second
* ordered by wait time desc, waits desc
* %Timeouts: value of 0 indicates value was < .5%. Value of null is truly 0
* Captured Time accounts for 95.7% of Total DB time 2,039.77 (s)
* Total FG Wait Time: 163.14 (s) DB CPU time: 1,789.38 (s)
Wait Class Waits %Time -outs Total Wait Time (s) Avg wait (ms) %DB time
DB CPU 1,789 87.72
User I/O 61,229 0 92 1 4.49
Other 102,743 40 31 0 1.50
Concurrency 3,169 10 24 7 1.16
Cluster 58,920 0 11 0 0.52
System I/O 45,407 0 6 0 0.29
Configuration 107 7 1 5 0.03
Commit 383 0 0 1 0.01
Network 15,275 0 0 0 0.00
Application 52 8 0 0 0.00
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Foreground Wait Events
* s - second, ms - millisecond - 1000th of a second
* Only events with Total Wait Time (s) >= .001 are shown
* ordered by wait time desc, waits desc (idle events last)
* %Timeouts: value of 0 indicates value was < .5%. Value of null is truly 0
Event Waits %Time -outs Total Wait Time (s) Avg wait (ms) Waits /txn % DB time
db file sequential read 27,531 0 50 2 18.93 2.45
db file scattered read 26,322 0 30 1 18.10 1.47
row cache lock 1,798 0 20 11 1.24 0.96
OJVM: Generic 36 42 15 421 0.02 0.74
db file parallel read 394 0 7 19 0.27 0.36
control file sequential read 22,248 0 6 0 15.30 0.28
reliable message 4,439 0 4 1 3.05 0.18
gc current grant busy 7,597 0 3 0 5.22 0.16
PX Deq: Slave Session Stats 2,661 0 3 1 1.83 0.16
DFS lock handle 3,208 0 3 1 2.21 0.16
direct path write temp 4,842 0 3 1 3.33 0.15
library cache load lock 39 0 3 72 0.03 0.14
gc cr multi block request 37,008 0 3 0 25.45 0.14
IPC send completion sync 5,451 0 2 0 3.75 0.10
gc cr block 2-way 4,669 0 2 0 3.21 0.09
enq: PS - contention 3,183 33 1 0 2.19 0.06
gc cr grant 2-way 5,151 0 1 0 3.54 0.06
direct path read temp 1,722 0 1 1 1.18 0.05
gc current block 2-way 1,807 0 1 0 1.24 0.03
os thread startup 6 0 1 108 0.00 0.03
name-service call wait 12 0 1 47 0.01 0.03
PX Deq: Signal ACK RSG 2,046 50 0 0 1.41 0.02
log file switch completion 3 0 0 149 0.00 0.02
rdbms ipc reply 3,610 0 0 0 2.48 0.02
gc current grant 2-way 1,432 0 0 0 0.98 0.02
library cache pin 903 32 0 0 0.62 0.02
PX Deq: reap credit 35,815 100 0 0 24.63 0.01
log file sync 383 0 0 1 0.26 0.01
Disk file operations I/O 405 0 0 0 0.28 0.01
library cache lock 418 3 0 0 0.29 0.01
kfk: async disk IO 23,159 0 0 0 15.93 0.01
gc current block busy 4 0 0 35 0.00 0.01
gc current multi block request 1,206 0 0 0 0.83 0.01
ges message buffer allocation 38,526 0 0 0 26.50 0.00
enq: FB - contention 131 0 0 0 0.09 0.00
undo segment extension 8 100 0 6 0.01 0.00
CSS initialization 8 0 0 6 0.01 0.00
SQL*Net message to client 14,600 0 0 0 10.04 0.00
enq: HW - contention 96 0 0 0 0.07 0.00
CSS operation: action 8 0 0 4 0.01 0.00
gc cr block busy 33 0 0 1 0.02 0.00
latch free 30 0 0 1 0.02 0.00
enq: TM - contention 49 6 0 0 0.03 0.00
enq: JQ - contention 19 100 0 1 0.01 0.00
SQL*Net more data to client 666 0 0 0 0.46 0.00
asynch descriptor resize 3,179 100 0 0 2.19 0.00
latch: shared pool 3 0 0 3 0.00 0.00
CSS operation: query 24 0 0 0 0.02 0.00
PX Deq: Signal ACK EXT 72 0 0 0 0.05 0.00
KJC: Wait for msg sends to complete 269 0 0 0 0.19 0.00
latch: object queue header operation 4 0 0 1 0.00 0.00
gc cr block congested 5 0 0 0 0.00 0.00
utl_file I/O 11 0 0 0 0.01 0.00
enq: TO - contention 3 33 0 0 0.00 0.00
SQL*Net message from client 14,600 0 219,478 15033 10.04
jobq slave wait 7,726 100 3,856 499 5.31
PX Deq: Execution Msg 10,556 19 50 5 7.26
PX Deq: Execute Reply 2,946 31 27 9 2.03
PX Deq: Parse Reply 3,157 35 3 1 2.17
PX Deq: Join ACK 2,976 28 2 1 2.05
PX Deq Credit: send blkd 7 14 0 4 0.00
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Background Wait Events
* ordered by wait time desc, waits desc (idle events last)
* Only events with Total Wait Time (s) >= .001 are shown
* %Timeouts: value of 0 indicates value was < .5%. Value of null is truly 0
Event Waits %Time -outs Total Wait Time (s) Avg wait (ms) Waits /txn % bg time
os thread startup 140 0 13 90 0.10 10.35
db file parallel write 8,233 0 6 1 5.66 5.08
log file parallel write 3,906 0 6 1 2.69 4.62
log file sequential read 350 0 5 16 0.24 4.49
control file sequential read 13,737 0 5 0 9.45 3.72
DFS lock handle 2,990 27 2 1 2.06 1.43
db file sequential read 921 0 2 2 0.63 1.39
SQL*Net break/reset to client 18 0 1 81 0.01 1.19
control file parallel write 2,455 0 1 1 1.69 1.12
ges lms sync during dynamic remastering and reconfig 24 100 1 50 0.02 0.98
library cache load lock 35 0 1 24 0.02 0.68
ASM file metadata operation 3,483 0 1 0 2.40 0.65
enq: CO - master slave det 1,203 100 1 0 0.83 0.46
kjbdrmcvtq lmon drm quiesce: ping completion 9 0 1 62 0.01 0.46
enq: WF - contention 11 0 0 35 0.01 0.31
CGS wait for IPC msg 32,702 100 0 0 22.49 0.19
gc object scan 28,788 100 0 0 19.80 0.15
row cache lock 535 0 0 0 0.37 0.14
library cache pin 370 55 0 0 0.25 0.12
ksxr poll remote instances 19,119 100 0 0 13.15 0.11
name-service call wait 6 0 0 19 0.00 0.10
gc current block 2-way 304 0 0 0 0.21 0.09
gc cr block 2-way 267 0 0 0 0.18 0.08
gc cr grant 2-way 355 0 0 0 0.24 0.08
ges LMON to get to FTDONE 3 100 0 24 0.00 0.06
enq: CF - contention 145 76 0 0 0.10 0.05
PX Deq: reap credit 8,842 100 0 0 6.08 0.05
reliable message 126 0 0 0 0.09 0.05
db file scattered read 19 0 0 3 0.01 0.05
library cache lock 162 1 0 0 0.11 0.04
latch: shared pool 2 0 0 27 0.00 0.04
Disk file operations I/O 504 0 0 0 0.35 0.04
gc current grant busy 148 0 0 0 0.10 0.04
gcs log flush sync 84 0 0 1 0.06 0.04
ges message buffer allocation 24,934 0 0 0 17.15 0.02
enq: CR - block range reuse ckpt 83 0 0 0 0.06 0.02
latch free 22 0 0 1 0.02 0.02
CSS operation: action 13 0 0 2 0.01 0.02
CSS initialization 4 0 0 6 0.00 0.02
direct path read 1 0 0 21 0.00 0.02
rdbms ipc reply 153 0 0 0 0.11 0.01
db file parallel read 2 0 0 8 0.00 0.01
direct path write 5 0 0 3 0.00 0.01
gc current multi block request 49 0 0 0 0.03 0.01
gc current block busy 5 0 0 2 0.00 0.01
enq: PS - contention 24 50 0 0 0.02 0.01
gc cr multi block request 54 0 0 0 0.04 0.01
ges generic event 1 100 0 10 0.00 0.01
gc current grant 2-way 35 0 0 0 0.02 0.01
kfk: async disk IO 183 0 0 0 0.13 0.01
Log archive I/O 3 0 0 2 0.00 0.01
gc buffer busy acquire 2 0 0 3 0.00 0.00
LGWR wait for redo copy 123 0 0 0 0.08 0.00
IPC send completion sync 18 0 0 0 0.01 0.00
enq: TA - contention 11 0 0 0 0.01 0.00
read by other session 2 0 0 2 0.00 0.00
enq: TM - contention 9 89 0 0 0.01 0.00
latch: ges resource hash list 135 0 0 0 0.09 0.00
PX Deq: Slave Session Stats 12 0 0 0 0.01 0.00
KJC: Wait for msg sends to complete 89 0 0 0 0.06 0.00
enq: TD - KTF dump entries 8 0 0 0 0.01 0.00
enq: US - contention 7 0 0 0 0.00 0.00
CSS operation: query 12 0 0 0 0.01 0.00
enq: TK - Auto Task Serialization 6 100 0 0 0.00 0.00
PX Deq: Signal ACK RSG 24 50 0 0 0.02 0.00
log file single write 6 0 0 0 0.00 0.00
enq: WL - contention 2 100 0 1 0.00 0.00
ADR block file read 13 0 0 0 0.01 0.00
ADR block file write 5 0 0 0 0.00 0.00
latch: object queue header operation 1 0 0 1 0.00 0.00
gc cr block busy 1 0 0 1 0.00 0.00
rdbms ipc message 103,276 67 126,259 1223 71.03
PX Idle Wait 6,467 67 12,719 1967 4.45
wait for unread message on broadcast channel 7,240 100 7,221 997 4.98
gcs remote message 218,809 84 7,213 33 150.49
DIAG idle wait 203,228 95 7,185 35 139.77
shared server idle wait 121 100 3,630 30000 0.08
ASM background timer 3,343 0 3,611 1080 2.30
Space Manager: slave idle wait 723 100 3,610 4993 0.50
heartbeat monitor sleep 722 100 3,610 5000 0.50
ges remote message 73,089 52 3,609 49 50.27
dispatcher timer 66 88 3,608 54660 0.05
pmon timer 1,474 82 3,607 2447 1.01
PING 1,487 19 3,607 2426 1.02
Streams AQ: qmn slave idle wait 125 0 3,594 28754 0.09
Streams AQ: qmn coordinator idle wait 250 50 3,594 14377 0.17
smon timer 18 50 3,505 194740 0.01
JOX Jit Process Sleep 73 100 976 13370 0.05
class slave wait 56 0 605 10806 0.04
KSV master wait 2,215 98 1 0 1.52
SQL*Net message from client 109 0 0 2 0.07
PX Deq: Parse Reply 27 44 0 1 0.02
PX Deq: Join ACK 30 40 0 1 0.02
PX Deq: Execute Reply 20 30 0 0 0.01
Streams AQ: RAC qmn coordinator idle wait 259 100 0 0 0.18
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Wait Event Histogram
* Units for Total Waits column: K is 1000, M is 1000000, G is 1000000000
* % of Waits: value of .0 indicates value was <.05%; value of null is truly 0
* % of Waits: column heading of <=1s is truly <1024ms, >1s is truly >=1024ms
* Ordered by Event (idle events last)
% of Waits
Event Total Waits <1ms <2ms <4ms <8ms <16ms <32ms <=1s >1s
ADR block file read 13 100.0
ADR block file write 5 100.0
ADR file lock 6 100.0
ARCH wait for archivelog lock 3 100.0
ASM file metadata operation 3483 99.6 .1 .1 .2
CGS wait for IPC msg 32.7K 100.0
CSS initialization 12 50.0 50.0
CSS operation: action 21 28.6 9.5 61.9
CSS operation: query 36 86.1 5.6 8.3
DFS lock handle 6198 98.6 1.2 .1 .1
Disk file operations I/O 909 95.7 3.6 .7
IPC send completion sync 5469 99.9 .1 .0 .0
KJC: Wait for msg sends to complete 313 100.0
LGWR wait for redo copy 122 100.0
Log archive I/O 3 66.7 33.3
OJVM: Generic 36 55.6 44.4
PX Deq: Signal ACK EXT 72 98.6 1.4
PX Deq: Signal ACK RSG 2070 99.7 .0 .1 .0 .1
PX Deq: Slave Session Stats 2673 99.7 .2 .1 .0
PX Deq: reap credit 44.7K 100.0
SQL*Net break/reset to client 20 95.0 5.0
SQL*Net message to client 14.7K 100.0
SQL*Net more data from client 32 100.0
SQL*Net more data to client 689 100.0
asynch descriptor resize 3387 100.0
buffer busy waits 2 100.0
control file parallel write 2455 96.6 2.2 .6 .6 .1
control file sequential read 36K 99.4 .3 .1 .1 .1 .1 .0
db file parallel read 397 8.8 .8 5.5 12.6 17.4 46.3 8.6
db file parallel write 8233 85.4 10.3 2.3 1.4 .4 .1
db file scattered read 26.3K 79.2 1.5 8.2 10.5 .6 .1 .0
db file sequential read 28.4K 60.2 3.3 18.0 18.1 .3 .1 .0
db file single write 2 100.0
direct path read 2 50.0 50.0
direct path read temp 1722 95.8 2.8 .1 .5 .8 .1
direct path write 6 83.3 16.7
direct path write temp 4842 96.3 2.7 .5 .2 .0 .0 .2
enq: AF - task serialization 1 100.0
enq: CF - contention 145 99.3 .7
enq: CO - master slave det 1203 98.9 .8 .2
enq: CR - block range reuse ckpt 83 100.0
enq: DR - contention 2 100.0
enq: FB - contention 131 100.0
enq: HW - contention 97 100.0
enq: JQ - contention 19 89.5 10.5
enq: JS - job run lock - synchronize 3 100.0
enq: MD - contention 1 100.0
enq: MW - contention 2 100.0
enq: PS - contention 3207 99.5 .4 .1
enq: TA - contention 11 100.0
enq: TD - KTF dump entries 8 100.0
enq: TK - Auto Task Serialization 6 100.0
enq: TM - contention 58 100.0
enq: TO - contention 3 100.0
enq: TQ - DDL contention 1 100.0
enq: TS - contention 1 100.0
enq: UL - contention 1 100.0
enq: US - contention 7 100.0
enq: WF - contention 11 81.8 18.2
enq: WL - contention 2 50.0 50.0
gc buffer busy acquire 2 50.0 50.0
gc cr block 2-way 4934 99.9 .1 .0 .0
gc cr block busy 35 68.6 31.4
gc cr block congested 6 100.0
gc cr disk read 2 100.0
gc cr grant 2-way 4824 100.0 .0
gc cr grant congested 2 100.0
gc cr multi block request 37.1K 99.8 .2 .0 .0 .0 .0 .0
gc current block 2-way 2134 99.9 .0 .0
gc current block busy 7 14.3 14.3 14.3 28.6 28.6
gc current block congested 2 100.0
gc current grant 2-way 1337 99.9 .1
gc current grant busy 7123 99.2 .2 .2 .0 .0 .3 .1
gc current grant congested 2 100.0
gc current multi block request 1260 99.8 .2
gc object scan 28.8K 100.0
gcs log flush sync 65 95.4 3.1 1.5
ges LMON to get to FTDONE 3 100.0
ges generic event 1 100.0
ges inquiry response 2 100.0
ges lms sync during dynamic remastering and reconfig 24 16.7 29.2 54.2
ges message buffer allocation 63.1K 100.0
kfk: async disk IO 23.3K 100.0 .0 .0
kjbdrmcvtq lmon drm quiesce: ping completion 9 11.1 88.9
ksxr poll remote instances 19.1K 100.0
latch free 52 59.6 40.4
latch: call allocation 2 100.0
latch: gc element 1 100.0
latch: gcs resource hash 1 100.0
latch: ges resource hash list 135 100.0
latch: object queue header operation 5 40.0 40.0 20.0
latch: shared pool 5 40.0 20.0 20.0 20.0
library cache load lock 74 9.5 5.4 8.1 17.6 10.8 13.5 35.1
library cache lock 493 99.2 .4 .4
library cache pin 1186 98.4 .3 1.2 .1
library cache: mutex X 6 100.0
log file parallel write 3897 72.9 1.5 17.1 7.5 .6 .3 .1
log file sequential read 350 4.6 3.1 59.4 30.0 2.9
log file single write 6 100.0
log file switch completion 3 33.3 66.7
log file sync 385 90.4 3.6 4.7 .8 .5
name-service call wait 18 5.6 5.6 5.6 16.7 44.4 22.2
os thread startup 146 100.0
rdbms ipc reply 3763 99.7 .3
read by other session 2 50.0 50.0
reliable message 4565 99.7 .2 .0 .0 .1
row cache lock 2334 99.3 .2 .1 .1 .3
undo segment extension 8 50.0 37.5 12.5
utl_file I/O 11 100.0
ASM background timer 3343 57.0 .3 .1 .1 .1 21.1 21.4
DIAG idle wait 203.2K 3.4 .2 .4 18.0 41.4 14.8 21.8
JOX Jit Process Sleep 73 2.7 97.3
KSV master wait 2213 99.4 .1 .2 .3
PING 1487 81.0 19.0
PX Deq Credit: send blkd 7 57.1 14.3 14.3 14.3
PX Deq: Execute Reply 2966 59.8 .8 9.5 5.6 10.2 2.6 11.4
PX Deq: Execution Msg 10.6K 72.4 12.1 2.6 2.5 .1 5.6 4.6 .0
PX Deq: Join ACK 3006 77.9 22.1 .1
PX Deq: Parse Reply 3184 67.1 31.1 1.6 .2
PX Idle Wait 6466 .2 8.7 4.3 4.8 .3 .1 5.0 76.6
SQL*Net message from client 14.7K 72.4 2.8 .8 .5 .9 .4 2.8 19.3
Space Manager: slave idle wait 722 100.0
Streams AQ: RAC qmn coordinator idle wait 259 100.0
Streams AQ: qmn coordinator idle wait 250 50.0 50.0
Streams AQ: qmn slave idle wait 125 100.0
class slave wait 55 67.3 7.3 1.8 5.5 1.8 7.3 9.1
dispatcher timer 66 6.1 93.9
gcs remote message 218.6K 7.7 1.8 1.2 1.6 1.7 15.7 70.3
ges remote message 72.9K 29.7 5.1 2.7 2.2 1.5 4.0 54.7
heartbeat monitor sleep 722 100.0
jobq slave wait 7725 .1 .0 99.9
pmon timer 1474 18.4 81.6
rdbms ipc message 103.3K 20.7 2.7 1.5 1.3 .9 .7 40.7 31.6
shared server idle wait 121 100.0
smon timer 18 100.0
wait for unread message on broadcast channel 7238 .3 99.7
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Wait Event Histogram Detail (64 msec to 2 sec)
* Units for Total Waits column: K is 1000, M is 1000000, G is 1000000000
* Units for % of Total Waits: ms is milliseconds s is 1024 milliseconds (approximately 1 second)
* % of Total Waits: total waits for all wait classes, including Idle
* % of Total Waits: value of .0 indicates value was <.05%; value of null is truly 0
* Ordered by Event (only non-idle events are displayed)
% of Total Waits
Event Waits 64ms to 2s <32ms <64ms <1/8s <1/4s <1/2s <1s <2s >=2s
ASM file metadata operation 6 99.8 .1 .1
DFS lock handle 6 99.9 .1 .0
OJVM: Generic 16 55.6 2.8 41.7
PX Deq: Signal ACK RSG 3 99.9 .0 .1
PX Deq: Slave Session Stats 3 99.9 .0 .0 .0
SQL*Net break/reset to client 1 95.0 5.0
control file sequential read 1 100.0 .0
db file parallel read 34 91.4 8.6
db file scattered read 4 100.0 .0 .0
db file sequential read 6 100.0 .0 .0 .0
direct path write temp 11 99.8 .1 .1 .0
enq: WF - contention 2 81.8 18.2
gc cr block 2-way 1 100.0 .0
gc cr multi block request 1 100.0 .0
gc current block 2-way 1 100.0 .0
gc current block busy 2 71.4 28.6
gc current grant busy 8 99.9 .0 .1
ges lms sync during dynamic remastering and reconfig 13 45.8 20.8 33.3
kjbdrmcvtq lmon drm quiesce: ping completion 8 11.1 11.1 77.8
latch: shared pool 1 80.0 20.0
library cache load lock 26 64.9 14.9 12.2 4.1 4.1
log file parallel write 2 99.9 .0 .0
log file sequential read 10 97.1 2.0 .6 .3
log file switch completion 2 33.3 66.7
name-service call wait 4 77.8 22.2
os thread startup 146 100.0
reliable message 4 99.9 .0 .1
row cache lock 2 99.7 .0 .0 .3
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Wait Event Histogram Detail (4 sec to 2 min)
* Units for Total Waits column: K is 1000, M is 1000000, G is 1000000000
* Units for % of Total Waits: s is 1024 milliseconds (approximately 1 second) m is 64*1024 milliseconds (approximately 67 seconds or 1.1 minutes)
* % of Total Waits: total waits for all wait classes, including Idle
* % of Total Waits: value of .0 indicates value was <.05%; value of null is truly 0
* Ordered by Event (only non-idle events are displayed)
% of Total Waits
Event Waits 4s to 2m <2s <4s <8s <16s <32s < 1m < 2m >=2m
row cache lock 6 99.7 .3
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Wait Event Histogram Detail (4 min to 1 hr)
No data exists for this section of the report.
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Service Statistics
* ordered by DB Time
Service Name DB Time (s) DB CPU (s) Physical Reads (K) Logical Reads (K)
ubshost 1,934 1,744 445 73,633
SYS$USERS 105 45 1 404
SYS$BACKGROUND 0 0 1 128
ubshostXDB 0 0 0 0
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Service Wait Class Stats
* Wait Class info for services in the Service Statistics section.
* Total Waits and Time Waited displayed for the following wait classes: User I/O, Concurrency, Administrative, Network
* Time Waited (Wt Time) in seconds
Service Name User I/O Total Wts User I/O Wt Time Concurcy Total Wts Concurcy Wt Time Admin Total Wts Admin Wt Time Network Total Wts Network Wt Time
ubshost 60232 90 2644 4 0 0 13302 0
SYS$USERS 997 2 525 19 0 0 1973 0
SYS$BACKGROUND 1456 2 1258 14 0 0 0 0
I am not able to paste the whole awr report. I have paste some of the sections of awr report.
Please help.
Thanks and Regards, -
I am running a DW application on 11.2.0.1, linux, using AMM. We have 64G memory, of which 45G is (theoretically) allocated to ORACLE.
I have noticed that the PGA size has increased substantially ( I'd expect this, being a DW with an MDX miiddle ), to about 40G, but I also notice that the SGA has remained static at about 20G (it was 25G). I've ailso noticed that the shared pool has ballooned from a few hundred MB to 7Gb in a matter of months. This is definitely increasing I/O which is unwanted.
Why does the shared pool get so big ? We are not a high turnover/large user number operation and parse times are a very small proportion of overall query time. Will a flush shrink the shared pool memory allocation or will it jsut clear the space ?OK, the allocated PGA will of course increase in response to demand, but I do not believe that the total PGA + SGA will ever break your 45G limit, and never has. I guess OEM is mis-representing something.
wrt the performance issue, I would question whether the size of the shared pool is in fact impacting on performance. The way I look at it is that no end user ever telphoned the help desk to say "the shared pool is too big" or "disc I/O is excessive". They may telephone to say "my queries are too slow". This throws you into the realm of query tuning, which would be a different topic.
wrt to memory usage and AMM, I believe that AMM does tend to assign more memory than needed to the shared_pool. If this really is a problem in your instance (and we don't know this yet) then you can set minimum values for the other SGA structures (usually, db_cache_size) to prevent this.
Hope this helps.
J. -
Hi All,
DB:oracle9iR2
os:solaris
how to get the shared_pool usage,free total size and hit ratio in oracle 9i R2?,can any one help to me....
POOL BYTES MB
shared pool used :
shared pool free :
shared pool (Total):
=================
Shared_pool hit ratio:
thanks.Hi All,
thank you for all the responses..
Db:oracle 9iR2
os :solaris
Actually i am facing below problem..
prob: ORA-00604: error occurred at recursive SQL level 2
ORA-04031: unable to allocate 4224 bytes of shared memory ("shared pool","select obj#,type#,ctime,mtim...","sga heap(1,0)","library ca
che")
Wed Feb 8 19:33:43 2012
Errors in file /ora/admin/cddp/bdump/cddp_cjq0_2601.trc:
ORA-00604: error occurred at recursive SQL level 2
ORA-04031: unable to allocate 4224 bytes of shared memory ("shared pool","select obj#,type#,ctime,mtim...","sga heap(1,0)","library ca
che")
Wed Feb 8 19:33:43 2012
Errors in file /ora/admin/cddp/bdump/cddp_cjq0_2601.trc:
ORA-00604: error occurred at recursive SQL level 2
ORA-04031: unable to allocate 4224 bytes of shared memory ("shared pool","select obj#,type#,ctime,mtim...","sga heap(1,0)","library ca
che")
Wed Feb 8 19:33:48 2012
Errors in file /ora/admin/cddp/bdump/cddp_cjq0_2601.trc:
ORA-00604: error occurred at recursive SQL level 2
ORA-04031: unable to allocate 4224 bytes of shared memory ("shared pool","select obj#,type#,ctime,mtim...","sga heap(1,0)","library ca
che")
========================================
i was running with 200MB size of share pool....couple of days back un expectdly i got above error....for temparory solution i did shared pool flush...
again nexday same error got repeated....for that i increased shared pool size to 420 MB....
while monitoring db it is using shared pool memory up to 400MB with avg shared pool hit ratio of 94.5 %..(database started recently)...
Earlier shared_pool size:200MB
Now:420 MB
Avg usage:up to 400MB
my question is :
1)if we have many different sql statements in shared pool ..won't
oracle flush share pool (ie aged out based on LRU or some alogorithm) if any program need memory in shared pool?
2) Any data Fragmentation will cause@above error?
3)can any one please explain..... how to check whats going on in Shared_pool(internally)...why it is using 400MB while compare to erlier avg usage 170MB .....any idea...(how to find root cause)..?
4)will plan table cause any issue ?
can any one explain to me...
thanks..
Edited by: kk001 on Feb 11, 2012 4:54 PM
Edited by: kk001 on Feb 11, 2012 4:56 PM -
What is "KQR M PO" in shared pool
Hi,
I am using oracle version 10.2.0.4. I fired below SQL.
select * from ( select pool,
name,
bytes/1024/1024 bytes
from v$sgastat
where pool='shared pool'
order by 3 desc
where rownum < 6;
POOL NAME BYTES/1024/1024
shared pool KQR M PO 404.138763
shared pool free memory 152.80159
shared pool KQR L PO 130.926659
shared pool sql area 114.5914
shared pool obj stat memo 84.535881
shared pool KQR ENQ 65.2046814
Any idea what is this "KQR M PO" in shared pool? Reason why i am asking this I am getting ora-4031 while executing below command.
drop user <user name> cascade;
So I was trying to monitor who is eating up this much space in shared pool.
Thanks in advance.
Best Regards,
oratestIf you still want to know why, poke about on Tanel Poder's blog and knowledgebase, he shows how to see all the subpool components and how to investigate these things.
X$KQR* tables describe rowcache, performance and parent/subordinate objects in the data dictionary.
select kqftanam from x$kqfta where kqftanam like 'X$KQR%'
SYS@TTST> /
KQFTANAM
X$KQRST
X$KQRPD
X$KQRSD
X$KQRFP
X$KQRFSSo wild speculation would be some bad mojo in recursive code for parent/child drop. -
Shared Pool _ Determine subpools & sizes
Hello guys,
as far as i know... oracle splits the shared pool into sub pools until 9i.
I can set a fix subpool count by using the hidden parameter "_kghdsidx_count".
But i want to know how oracle setup the size of the subpools if kghdsidxcount is not set. I was not able to find any document where the algorithm was described.
I have read something about bugs with the subpools (for example Metalinknote 4184298.8 or 4994956.8), because we are recieving a ORA-4031 but in the shared pool (v$sgastat) there is enough free space - i also have check ed the fragmentation - that was not the problem :)
I want to know how i can monitor the different sub pools and what is the algorithm for creating the sub pools?
Maybe someone of you knows a document .
Thanks and Regards
StefanArrrgs no need to go on with this topic..
I have found Metalinknote 396940.1 - there is anything i need.
Regards
Stefan
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