Performance Tuning :: Snap IDs Not Found For Awr Reports Generation
Oct 24, 2011
When I want to generate AWR report for database, I dont see any Snap IDs. What was disabled?
Is it possible to generate awr reports for unseen snap IDs?
Here below is the log:
Current Instance
~~~~~~~~~~~~~~~~
DB Id DB Name Inst Num Instance
----------- ------------ -------- ------------
49472052 WPSDBSTG 1 wpsdbstg
Specify the Report Type
~~~~~~~~~~~~~~~~~~~~~~~
Would you like an HTML report, or a plain text report?
Enter 'html' for an HTML report, or 'text' for plain text
Defaults to 'html'
Enter value for report_type: html
Type Specified: html
Instances in this Workload Repository schema
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
DB Id Inst Num DB Name Instance Host
------------ -------- ------------ ------------ ------------
* 49472052 1 WPSDBSTG wpsdbstg rcolnx88700
Using 49472052 for database Id
Using 1 for instance number
Specify the number of days of snapshots to choose from
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Entering the number of days (n) will result in the most recent
(n) days of snapshots being listed. Pressing <return> without
specifying a number lists all completed snapshots.
Enter value for num_days: 1
Listing the last day's Completed Snapshots
Specify the Begin and End Snapshot Ids
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Enter value for begin_snap:
Is it possible to generate AWR report for the duration of 5 min? As we know that snapshots are generated for every 1 hour, which we specified in parameter.
By changing the parameter to 2 min, what could be the impact on database?
At my prod instance one sql query ran for about 9 hours.Now the sql query completed with success.Suddenly our ops team want to know the which sql query was running for 9 hours.As the query got success no record is being found at session level.
I am using : Database : Oracle 8i Application Server: Oracle AS 9i Developer Suite : Oracle 6i(forms & reports)
I have created some character reports in oracle reports 6i.. when reports used run from my ERP(oracle 6i oriented) ... report usually took time to create on server. Sometimes my ERP used to hang up due to reports lock. And then we have to kill some processes to finally create charater reports in emergency basis.
What is the valid reason for locks on report(character file )creation.?
Looking to understand the difference between instance tuning and database tuning.
What is the difference between these two tuning exercises? I understand that an instance is memory based structures (logical) where as database consists of physical structures.
However, how does one tune a database the physical structure? Does it have to do with file placements/block sizes etc. Would you agree that a lot of that is taken care by ASM now in 11g? What tools are required/available (third party as well as oracle supplied) for these types of tuning scenarios?
I have two tables with 113M records in DWH_BILL_DET & 103M in prd_rerate_chg_que and Im running following merge query, which is running for 13 hrs to update records, which is quiet longer time.
SQL> explain plan for MERGE /*+ parallel (rq, 16) */ INTO DWH_BILL_DET rq USING (SELECT rated_que_rowid, detail_rerate_flag_code, rerate_sel_key,
How the length of column width effects index performance?
For example if i had IOT table emp_iot with columns: (id number, job varchar2(20), time date, plan number)
Table key consist of(id, job, time)
Column JOB has fixed list of distinct values ('ANALYST', 'NIGHT_WORKED', etc...).
What performance increase i could expect if in column "job" i would store not names but concrete numbers identifying job names. For e.g. i would store "1" instead 'ANALYST' and "2" instead 'NIGHT_WORKED'.
I have a question about database fragmentation.I know that fragmentation can reduce performance in query times. The blocks are distributed in many extents and scans process takes a long time. Oracle engine have to locate the address of the next extent..
I want to know if there is any system view in which you can check if your table or index has high fragmentation. If it's needed I will have to re-create, move or rebulid the table or index, but before I want to know if the degree of fragmentation is high.
Any useful script or query to do this, any interesting oracle system view?
There is a simple way to increase the performance of a query by reducing the row-size of the table it hits. I used it in the past by dividing the table into smaller parts and querying respective smaller table in each query.
what is this method called ? just forgot the method and can't recall it. what this type of row-reduction optimization is called ?
I previously received REP-51002; searched over the forums,& made changed to the rwservlet properties file by setting my Server,setting the trace on,& changing my host file in windows.
Errors received now: REP-52266: The in-process Reports Server rep_fsprod failed to start.oracle.reports.RWException: IDL:oracle/reports/RWException:1.0
I also tried these commands:
rwclient server=rep_CC-BA0C7240E38E report=test destype=cache desformat=html GIVES ERROR:- REP-0178: can not connect to reports server
rwdiag -findall Broadcast mechanism used to locate servers Channel address: 228.5.6.7 Channel port: 14021 REP-50503 No server found in the network.
Here is my req - There are 2 columns C1, C2 - both of which capture a different set of values in 2 seperate custom oracle apps forms.
I have a RDF query to get the result set of C1,C2.
When this query does not return any values I need to look in form 2 and handle each value of C1 separately. I do not know how to achieve this with formula column - since I can perform checks/validations on the data returned by the query using a formula column.
How many records could I have in a single table without performance degradation with Standard Edition without partitioning with cutting-edge server (8 or 12 cores, 72 GB RAM, FC 4 Gbit, etc...) and good storage?
300 Millions in only one table with 500K transactions / day is too much?
Testing our 9i to 11g upgrade, we've imported the entire DB into the new machine.We've found that certain procedures are really suffering performance problems. BUT, we've also found, that if we check out a production copy of the procedure from our source code control, and reinstall it, the performance issue goes away. Just alter the procedure and recompiling does NOT work.
The new machine where the 11g database exists is slightly different than the source, but it's not like we have this problem with every procedure. It's only a couple.
any possible reason that we'd have to re-install a procedure to correct a performance problem?
I need to check the package performance and need to improve the package performance.
1. how to check the package performance(each and every statement in the package)? 2. In the package using the delete statement to delete all records and observed that delete is taking long time to delete all the records in the table(Table records 7000000). This table is like staging table.Daily need to clean the data before inserting the data into it. what can I use instead of Delete.
Somewhere I read that we should not use hints in Oracle production environments, but we can use hints in the development environment and on achieving the desired execution plan we can adjust the 'statistics' to follow that plan without hints.
Q1. If it is true what statistics do we adjust for influencing the execution plan and how?
For example, I have the following simple query:
select e.empid, e.ename, d.dname from emp e, dept d where e.deptno=d.deptno;
emp.empid, emp.deptno and dep.deptno columns have indexes and the tables have the standard structure as found in the basic oracle examples.
If I look at the execution plan of the above query then I see that the driving table is empand the driven table is dept.Also the type of join that is taking place is 'Nested Loop'.
Questions: With respect to the above query, Q 2. If I want to make dept the driving table and emp the driven table then how can I adjust the statistics to achieve that? Q 3. If I want to use hash join instead of a nested loop join then then how can I adjust the statistics to achieve that?
I can put the ordered and the use_hash hint to effect this but again I have heard that altering statistics is a more robust way to control an execution plan as compared to hints.
When i exporting an user using expdp utility, the load the on the server is going up-to 5. The size of the database is 180GB. Below is the command that i use for export.
I have an existing view that stores some data. I was asked to create a table based on the columns present in the view. I only copied the table structure from the view.
Now I would need to create a stored procedure that executes the query and stores the data in the table with a snap id and date of snap column. The reason this needs to be done is to show differences over time for historical and trending.
I have some questions about Oracle + EMC shared storage. I have Oracle 11gR1 RAC (2nodes) + ASM environment with shared shorage EMC Clariion AX4.
The database is running no archivelog mode. I'd like to implement point-in-time recovery using Snap View snapshots.
Currently my AX4 platform has the following LUNS:
LUN1 - registry 1 LUN2 - registry 2 LUN3 - vote 1 LUN4 - vote 2 LUN5 - vote 3 LUN6 - ASM - DISKGROUP DATA DISK DATA01 (actual db datafiles) LUN7 - ASM - DISKGROUP DATA DISK DATA02 (actual db datafiles)
Using source LUNs in consistent session will take sync snapshots of all the LUNs working against my database. Once something happens with database, the LUNs can be returned to specific point in time when snapshot consistent session was taken and I'm expecting the database will up and continue to work.
Questions:
1. Is my approach correct at all? (The database is running noarchivelog mode, not dealing with hot backups. The recovery point in time implemented purely via EMC snapshot consistent sessions.) 2. The AX4 platform has a limit 8 source LUNs in session. If I understand it correctly, I can't place more than 8 LUNs in session. What will be the workaround if my database will occupy more than 8 LUNs, I'd like to take their consistent snapshot; for example:
LUN1 - registry 1 LUN2 - registry 2 LUN3 - vote 1 LUN4 - vote 2 LUN5 - vote 3 LUN6 - ASM - DISKGROUP DATA DISK DATA01 (actual db datafiles) LUN7 - ASM - DISKGROUP DATA DISK DATA02 (actual db datafiles) LUN8 - ASM - DISKGROUP DATA DISK DATA03 (actual db datafiles) LUN9 - ASM - DISKGROUP DATA DISK DATA04 (actual db datafiles)
The following query gets input parameter from the Front End application, which User queries to get Reports.There are many drop down boxes like LOB, FAMILY, BRAND etc., The user may or may not select values from drop down boxes.
If the user select any one or more values ( against each drop down box) it has to fetch all matching values from DB. If the user does'nt select any values it has to fetch all the records, in this case application will send a value 'DEFAULT' (which is not a value in DB ) so that the DB will fetch all the records.
For getting this I wrote a query like below using DECODE, which colleague suggested that will hamper performance.From the below query all the variables V_ are defined in procedure which gets the values selected by user as a comma separated string here V_SELLOB and LOB_DESC is column in DB.
DECODE (V_SELLOB, 'DEFAULT', V_SELLOB, LOB_DESC) IN OPEN v_refcursor FOR SELECT /*+ FULL(a) PARALLEL(a, 5) */ * FROM items a WHERE a.sku_status = 'A'
what the principal things to look at when we have for the same query different performance results are?I have 2 different bases: the plan and data are the same but performance results are very differents.
are the most important performance keys we have to calculate or take in account to preserve or to increase the DB performance in terms of response times, and whatsoever according to performance ?
I have an Image Type on a forum page. I want a default "not-found" image to display if the BLOB column value is null or if there is no data for that search value. The image is stored with the app: #APP_IMAGES#not-found.png
I am working on an assignement where client is using Oracle 10g but stuck to using RBO Now the application team, from the GUI available to them build dynamic queries and some of them run very slow.
Neither the code can not be changed to tune the queries nor do we get the exact step in the plan which is an issue (being RBO).For some long running queries the Tuning advisor is not producing any recommendations.
Another hurdle is that all the application users are using same application user id so we can not write a logon trigger to use CBO for some particular queries to see what is happening in the background!
I want to tuning the next sql sentence. In this sql I want to get the hash_value and sql_text of the sentences that it's causing TX blocks. Is it possible?. This sentence works fine but sometimes It's slow.
SELECT DISTINCT hash_value, sql_text FROM gv$sql sq WHERE hash_value IN (SELECT DISTINCT prev_hash_value FROM gv$session se WHERE sid IN (SELECT sid FROM gv$lock l WHERE type = 'TX' AND ctime >= 2000 AND l.inst_id = se.inst_id AND l.sid = se.sid) AND sq.inst_id = se.inst_id); [code]....
I see one of my SQL's which is ran by the user on a 10.2.0.3 database changing its SQL_ID after some runs even if the query is not changed a bit! However the HASH VALUE for this query remains the same.
how a same query can have different SQL_ID's but same HASH_VALUE?
Note: Statistics are not modified on the base tables of this query.
I am running Oracle 10.2.0.1.0 on MS Windows 2003 server 64-bit with 16G RAM.
Here is the findings for my Oracle database.
SQL> select * * from v$sgainfo; NAME BYTES RES -------------------------------- ---------- --- Fixed SGA Size 1293560 No Redo Buffers 7094272 No Buffer Cache Size 830472192 Yes
[code]...
I find that the SGA component "Buffer Cache" is decreasing from the start "1.8G" and down to now 0.8G. On the other hand, the component "Shared Pool" is increasing from the start 0.3G to now 1.2G. I noticed that there are 100 operations of shrinking of "Buffer cache" and growth of "Shared Pool" in Oracle every day.Is it a indicator that I should raise up the SGA_MAX_SIZE?
I tried to increase the SGA_MAX_SIZE to 4G. But I cannot start the Oracle afterward.Is it a limitation of MS Windows(OS) or Oracle?I set the SGA_MAX_SIZE to 3G. This time, I can startup Oracle.What is the optimum/maximum I can set to SGA_MAX_SIZE?Is there any adverse effect/concern when setting the SGA_MAX_SIZE more than 2G?
Here i have three tier application. I want to know it host name from sid or sqlid . I want to know which query run on which host. Because i have one user from application to database. So i want to know which query consume more time on which host ?
