On 10gR2, I cannot find the exact definition of the 2 following metrics :
"Physical Read Total Bytes Per Sec"
and
"Physical Read Bytes Per Sec"
I would want to know what is the difference between them.
AWR Report regarding ' SQL ordered by Physical Reads (UnOptimized))'. SQL ordered by Physical Reads (UnOptimized)UnOptimized Read Reqs =
Physical Read Reqts - Optimized Read Reqs %Opt - Optimized Reads as percentage of SQL Read Requests %Total - UnOptimized Read Reqs as a percentage of Total UnOptimized Read Reqs Total Physical Read Requests: 3,311,261 Captured SQL account for 13.5% of Total Total UnOptimized Read Requests: 3,311,261 Captured SQL account for 13.5% of Total Total Optimized Read Requests: 1 Captured SQL account for 0.0% of Total UnOptimized Read ReqsPhysical Read ReqsExecutionsUnOptimized Reqs per Exec%Opt%TotalSQL IdSQL ModuleSQL
[code]....
I want to know what is the mean by 'UnOptimized Read Reqs' and 'Optimized Read Reqs 'Question 2) what is 'SQL ordered by Physical Reads tuning'.
I need to have below details from production database(11.2.0.3 or 10.2.0.4).
1.Cache hit ratios for a day, for a week, for a month.
2.Top 10 sql command sorted by elapsed time, cpu time, physical read/write. This is also for a day, for a week, for a month.
3.Top 5 wait event of a day, of week, of month.
Well I don't want to use awrrpt.sql script. I want to do it through queries.
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,
[code].....
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 ?
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?
Simple database with simple schema.
How many records begin to be too many?
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.
I have an issue with export(expdp).
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.
expdp sys/xxxx directory=dbpdump dumpfile=expdp_trk_backup.dmp logfile=expdp_trk_backup.log exclude=statistics schemas=trk
Do i need any look into any memory parameters for this?
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'
[code]...
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.
View 10 Replies View RelatedWhen looking at some of the metrics available in OEM, I am puzzled by the interpretation:
1) Using the Host tab, and load metrics, I can get a metric for the Total I/O for the host .. I assume this is IOPS.
2) Using the Database tab, and the instance_throughput physreads_pc metric I can get a metric for the Physical Reads from the database instance per second.
3) We generally have several Oracle instances on the same server, and in all cases, the sum of the physical reads for each database is SIGNIFICANTLY higher that the total i/o for the host.
Am I interpreting the information incorrectly ? Does one of the metrics consider db_block_size ?
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 ?
View 8 Replies View RelatedAny complete List iof possible Metrics from Grid Control after installarion? No User-Defined, only Standard Metrics. How can I find them, I just checked Documentation and Metalink - but no result.
Any list prepared before or can point to any "how to create".
Does the counter of event buffer gets include the logical reads ? Does the mertic buffer gets include the event of reading from undo buffer ?
View 4 Replies View RelatedI have created some views in one SCHEMA and made it invalid by dropping it's base table
1) Thru some queries, on SQL, I checked it shows there are invalid objects.
2) But even though , I refreshed DBCONSOLE Home Page it doesn't show the invalid objects.
3) How frequently ALERT METRICS are collected/refreshed.
Attached query taking 80000 reads to execute...
View 8 Replies View RelatedI am having performance issues on a query in a production environment that I cannot replicate in our test environment. Our test environment is an import of production. Version information is:
Oracle Database 10g Enterprise Edition Release 10.2.0.3.0 - 64bi
PL/SQL Release 10.2.0.3.0 - Production
CORE 10.2.0.3.0 Production
TNS for Solaris: Version 10.2.0.3.0 - Production
NLSRTL Version 10.2.0.3.0 - ProductionWhen I run the query in test, I get the following results using TKPROF
[code]....
Misses in library cache during parse: 1
Optimizer mode: ALL_ROWSThis performance problem started a few weeks ago and the problem seems to be in the high number of consistent reads during fetch. The DBA tried restarting the instance and gathering fresh stats on the tables but that has not made a difference. Now he wants to export the tables, drop the schema and re-import.
Firstly the table structures :
Create table cd_patient (pat_mrn varchar2(100)) ;
Create table cd_encount (pat_mrn varchar2(100), encounter_id varchar2(1000));
I need to write a code which dynamically reads the table name from user_tables (starting with cd) & load the data from remote database which has the same table name & structure based on the load number..
Static PLSQL statement would be :
declare
BEGIN
INSERT INTO "cd_patient" C-- DYNAMICALLY GET THE TABLE NAME
SELECT C1.PAT_MRN -- DYNAMICALLY GET THE COLUMN NAME
FROM REMOTE_DB.CD_PATIENT@XXX C1
WHERE C1.LOAD_NUMBER > 2;
[code]....
My understanding of DB_FILE_MULTIBLOCK_READ_COUNT parameter is that it affects only Full Table Scans and Fast Full Index Scans - all other disk retrieval is single block.If so, then maybe I'm reading this trace incorrectly:
select /*+ first_rows */ pk
from test_join_tgt
where pk >= 0
and rownum > 1
call count cpu elapsed disk query current rows
------- ------ -------- ---------- ---------- ---------- ---------- ----------
Parse 1 0.01 0.00 0 0 0 0
Execute 1 0.00 0.00 0 0 0 0
Fetch 1 21.48 27.77 22368 22134 0 0
------- ------ -------- ---------- ---------- ---------- ---------- ----------
total 3 21.49 27.78 22368 22134 0 0
[code]...
What the heck is going on with the Multi-block reads in the Range Scan?
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 ?
View 19 Replies View RelatedHow can I disable redo generation for DML statements.
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