Metric Row Cache Hit Ratio In V$SYSMETRIC_HISTORY?
Mar 16, 2013understand the metric Row Cache Hit Ratio in V$SYSMETRIC_HISTORY? Is it the dictionary cache hit ratio?
View 1 Repliesunderstand the metric Row Cache Hit Ratio in V$SYSMETRIC_HISTORY? Is it the dictionary cache hit ratio?
View 1 Replieswhat will be best buffer cache hit ratio for a database for good performance
note : in general
Database : 9.2.0.7
Os : windows 2003 sevrer standdard edition
RAM 4 Gigs
The buffer cache hit ratio in this server is around 83%, where it normaly was around 98% before i did some maintenance activities.
I have done some maintenance activities in January on this database.
Maintenance activties includes below steps
1.In production i have deleted old data in the production tables
2.Reorganized tablespaces,tables
3.Rebuild indexes for those tables.
4. At last collected statistics for those tables.
Now after this activity the buffer cache hit ratio is very low.
We are getting Negative values of Library cache hit ratio in AWR Report of 11g(11.2.0.3) with Solaris[tm] OE (64-bit). Why it shows negative value.
Instance Efficiency Percentages (Target 100%)
Buffer Nowait %: 99.87 Redo NoWait %: 99.99
Buffer Hit %: 92.17 In-memory Sort %: 100.00
Library Hit %: -3,321.23 Soft Parse %: 81.95
Execute to Parse %: 92.88 Latch Hit %: 95.11
Parse CPU to Parse Elapsd %: 87.25 % Non-Parse CPU: 81.39
What is the difference between cache fusion and Cache Coherency. Both are same or different functionality.
View 1 Replies View RelatedI have some question.
TTversion : TimesTen Release 11.2.2.3.0 (64 bit Linux/x86_64) (tt112230:53376) 2012-05-24T09:20:08Z
We are testing a AWT cache group ( with CacheAwtParallelism=4 ).
Application(1 process) to the DML generates to TimesTen(DSN=TEST).
At this point, Are delivered to the 4 parallel DML?
[TEST]
Driver=/home/TimesTen/tt112230/lib/libtten.so
DataStore=/home/TimesTen/DataStore/TEST/test
PermSize=1024
TempSize=512
PLSQL=1
[code].......
,i had given the sample data below
create table ex (sno number,ename varchar2(10),job_code char(4),sal number);
insert into ex values(101,'John','Java',21000,'IT');
insert into ex values(102,'Michel','BI',25000,'IT');
insert into ex values(103,'Johny','Java',30000,'IT');
[code]...
My expected output is attached in a text file
Is it possible to easily set up a single User Defined Metric, to monitor all the users quotas? I know I can do it, if I make individual metrics for each user. But was hoping there was a simple way of combining them all into a single metric.
I am using Oracle 10G2 Standard Edition on a windows 2003 Server.
SQL> select name,decode(unit,'bytes',value/1024/1024,value) as mb from v$pgastat; NAME MB---------------------------------------------------------------- ----------aggregate PGA target parameter 25600aggregate PGA auto target 2724.14648global memory bound 1024total PGA inuse 22601.7333total PGA allocated 26653.6230maximum PGA allocated
[code]....
I understand I have soft limit( aggregate PGA target parameter) which was overlimited (maximum PGA allocated = 35374.4638) hence we have over allocation count>0.Extra bytes read/written=13GB,hence we have excessive 13Gb that we had to flush on disk(excessive I/O operations) cause of limitation in 1024MB(global memory bound)(it's not enough to join or to sort something so we must do onepassor multipass) ,which defines the size of single operation of sort or join(so does it mean that it's some kind of sort_area_size and hash_area_size for automatic workarea_size_policy? and in this case what about _smm_max_size?)aggregate PGA auto target - is the amount of space(total) that Oracle can give for work areas running in automatic mode.
So I can't understand ratio between global memory bound and aggregate PGA auto target - why does the aggregate PGA auto target such tiny?(relatively process count)?Is the global memory bound static for particular aggregate PGA target parameter?
I can change it only by redefining aggregate PGA target parameter?What would be with aggregate PGA auto target if I started 10 sort operation and each of them takes about 1Gb of memory.How huge it would be? 10Gb?
How can I apply a user metric for DB (single database) using a script or cli?
clear my question:
Can I create a User Defined Metric using SQL code, and not via the graphical interface?
My Configuration:
OEM Grid Control: 10.2.0.5
Oracle Database: 10.2.0.4
Task: Enable Metric Baseline with moving window of trailing 7 days using sqlplus.
Issue Background: I am not able to login into database from OEM using SYS user. Remote login using SYS is disabled on database.
Question: Is there a way to enable metric baselines using sql commands while logging locally onto database server using SYS user?
I'm attempting configure User-defined Metric to send mails when happen warning or critical alerts .My environment is Cluster Database and I'm using OEM Grid Control
I created User-defined Metric for monitoring invalid object for example and scheduled this collect to every 5 minutes.On initial OEM page, I see alert violation, but don't receive mail for this. In my Notification Rules page, I added "User-Defined Numeric Metric" and includes object Check_Invalid_Objects, wich is my UDM.I receive several alerts violations, but don't UDM.
UDM_Violation.png ( 116.68K )
Number of downloads: 0
NotificationRule.jpg ( 218.78K )
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What are all the necessary steps in running a Windows OS .bat when a metric threshold has been tripped? Currently have a fully qualified path (C:scriptsRunthis.bat) entered in the Response Action column but no action is taken when threshold is reached.
View 5 Replies View RelatedWhen I view Database Throughput Metric Data, e.g. Consistent Read Gets (per second) using "Real Time: 30 Second Refresh", it appears that timestamp are 5 hours behind the current time. This can be also observed by "Last Upload" timestamp from "All Metrics" view of the database instance for "Throughput" Metrics.
It was not like this for EM GC10.2.0.2. I'm wondering if anything changed in GC 11g.
I even tried to set low alarm thresholds for "Consistent Read Gets" metric, it doesn't seems to work on the timestamp of the realtime data.
i have a application which uses 32 tables for retrieval in this 4 tables are important and have a size more than 100 mb can i move the index of these 4 tables cache memory to improve the applications retrieval performance if i done so ,then that will affect any other applications performance
View 1 Replies View RelatedAre there any recommendations or good practices to set sequence CACHE parameter (for example one caching per hour, day etc)?
View 4 Replies View RelatedI have a query - whch used to be run in 30 minutes and now hangs on for hours and not finishing. The wait i see is
wait event latch: cache buffers chains.
This is a 11.1.0.7 2 Node RAC environment runing on HP-UX Itanium.
i m working on oracle 10g using db_block_buffers. But i m not able to get information from database cache advice. Is there any method or procedure to activate cache advice despite of db_block_buffers use?
View 2 Replies View RelatedWhat is cache/no cache & cycle/no cycle in Sequence?what is the use?
View 3 Replies View Relatedhow can we check the size of data buffer cache.
View 7 Replies View RelatedIn Oracle 9i
I know that db_block_size defines the standard/default block size for my datafiles.
I know db_cache_size defines the size of the my default database buffer of the size of my standard/default block size.
db_block_size = 8192 (8k)
db_cache_size = 200Mo of 8k block
Is there any needs for the other buffer cache
db_16k_cache_size
db_4k_cache_size
db_32k_cache_size
and so on?
If I have NO datafiles other than of the default block size, would I need to define a size for those other buffer pool? Is there any process that would benifit of these pools?
I want to know what exact process happens in oracle architecture when an update query is fired.
View 1 Replies View RelatedAt a customers site I see lot of long lasting library cache locks during a complex ETL run. Several Sessions run in parallel and create Database tables with dynamic sql ( CREATE TABLE AS SELECT ....) .
Sometimes these procedures wait for each other with wait event 'Library Cache' . I presume that this is a side effect of the dynamic DDL in the stored procedures. Is that possible even when the Procs create different Tables but reference the same tables in their SELECT clauses ?
I presume that this is plausible but I need some arguments to convince my colleagues.
11.2.0.2.0
OEL.
Design stage of New SAN. I can put a lot of the database, including redo on SSD.
1. Hardware sub tiering enabled. Has anyone ever gauged performance with enabling 11g Smart flash cache using the SSD as the flash device even with the hardware subtiering on? ie, if the hardware subtiering is moving hotblocks to most performant disk, is there much significant benefit having the flash cache on. Im guessing yes as the flash cache is working at the SGA level.
2. To redo or not to redo on SSD. Many notes say not to so as to avoid log file sync waits. Is there a way to keep it on the SSD and avoid the waits? Is there any risk of enhanced degradation of the disks over time with having so much sequential writes from the redo if I leave it on there?
How to Minimise Waits for 'Log File Sync' [ID 857576.1] (discusses keeping redo off ssd but only generally)
[URL]
Is db_cache_advice = ON still necessary when sga_target is set?
View 2 Replies View RelatedI have an application built in Apex 4.2It's been running fine for several weeksI've not made any changes to the codeSuddenly it developed what seems to be a cache problem.If I enter a search criteria; it displays results. I enter a different search criteria and it brings back the same results as the first criteria.I enter a search criteria in a different field and I still get the results from the first searchI go from Internet Explorer to Mozilla.
DIfferent search criteria, but same issue. Google chrome - same issueThe obvious answer is to clear the cache.I have a process set up that is clear Cache for Items , on submit after computations and validations and then I list all the items individually.This process has been there all along.
I never had this problem before.If I log out and come back in, same issue. What ever I enter as the first search criteria is the results no matter how I search
give a script to find how much my db buffe cache and redo log buffer cache is used and how much is free.
View 1 Replies View RelatedHow to move a partition of a table to db_keep_cache ?
View 8 Replies View RelatedConsidering the below factors, I am planning to increase the buffer cache value from 256Mb to 512Mb.
1. Buffer cache hit ratio value is around 35% even in the normal period.
2. free buffer requested value is below during peak & normal hours below.
Statistic Total per Second per Trans
--------------------------------- ------------------ -------------- ------------
free buffer requested 54,694,995 15,226.9 2,523.7
free buffer requested 23,412,674 6,501.7 2,585.9
3. most of the top 5 physical reads & logical reads queries are well tuned and some of queries are doing FTS on small tables (table count min 1500 max 35000). SO indexing option is not required for these queires. But these queries getting executed frequently.
SQL> show sga
Total System Global Area 2148534928 bytes
Fixed Size 731792 bytes
Variable Size 1879048192 bytes
Database Buffers 268435456 bytes
Redo Buffers 319488 bytes
5.top 5 waitevents during db slow performance & high cpu utilization (>80%) issue.
Top 5 Timed Events
~~~~~~~~~~~~~~~~~~ % Total
Event Waits Time (s) Ela Time
-------------------------------------------- ------------ ----------- --------
latch free 1,848,898 153,793 52.00
buffer busy waits 395,280 87,201 29.49
db file scattered read 3,488,648 34,199 11.56
enqueue 4,052 10,897 3.68
CPU time 5,567 1.88
6. Top 5 waitvents during normal activities and CPU utilization is around 40%.
Top 5 Timed Events
~~~~~~~~~~~~~~~~~~ % Total
Event Waits Time (s) Ela Time
-------------------------------------------- ------------ ----------- --------
CPU time 1,860 45.32
db file scattered read 1,133,669 985 23.99
imm op 776 605 14.73
sbtinfo2 208 139 3.40
sbtbackup 2 123 3.00
1) Is shutting down the DB flush all the data buffers, from the buffer Cache?
2) In any oracle version, do we have any way to flush only the buffer Cache.