We have a program that is taking about 13-14 hours to run and we need to generate traces to see where it is taking so long. I usually use 10046 for the tracing, I'm wondering if the traces can be built incremently so that it doesn't become one huge trace file.
View 14 RepliesI have a Datamart DB which has a continuously increasing volume. I run a daily optimize job, to have the data analysed using the below:-
EXECUTE dbms_stats.gather_schema_stats(ownname=> 'xxx' ,estimate_percent=> 25 , DEGREE => 4, cascade=> TRUE );
analyze table xxx.abc compute statistics; But this optimization itself is taking nearly 4 hrs to complete and I can't afford to have the delay.
Is there a better way of running this optimization?
I have a Query(report) which is running in <5 mins in one Scheme, where as the same is running for a long time in second schema. I have identified that an Index is scanning for more than 2000 Millions of records in second Schema, but this is scanning only 440 Millions in First Schema and hence it is fast. I am expecting the same to be done in Second schema.
I have verified the following
All records in tables in 2 schemas are same.
All indexes are same
Analyzed the tables
Gathered Histogram on all the columns as per the first schema.
But now i still have the same problem, don't know what could be the problem.
Table_nameNum_RowsBlocks
PRPSL_LST_T5866107159
PRPSL_WKFLW_ACTVTY_T5829904030
ITEM_CHR_VAL_T5134340104049020
ITEM_RGN_ASSN_T8571220137215
Also attached 2 screen shots of OEM Plans..
How to enable tracing for sessions connected using shared servers ?
View 1 Replies View RelatedI have been used to the consciousness that we should use the minimum length for varchar2 field that can store the data we need manipulate. But recently I was told that it has little impact on performance if we assign a much longer size.
View 13 Replies View RelatedWe have a huge table in production, with LONG column. We are trying to change its datatype to CLOB. The table has 120 Million records and is of 270 GB in size.
We tried using the oracle expdp/impdp option to try the conversion in our perf environment. With 32 parallels, the export completed in 1.5 hrs. However, the import took 13 hrs.
I also tried the to_lob option using inserts, it went on for 20 hrs and I killed the process. Are there any ways to improve the performance of LONG to CLOB conversion on huge tables?
the reason behind the below statements:
1) We cant create TABLE PARTITIONED on CLUSTER or INDEX on CLUSTER TABLE.
2) We cant create a partitioned table with the column of LONG or LONGRAW? (But how it could be possible with BLOB, CLOB?
I am getting temp tablespace error "ORA-01652: unable to extend temp segment by 128 in tablespace TEMP" for the following code.
SELECT /*+ USE_NL ( vd1 ,vd2 ,vd3 ) leading ( vd1 ,vd2 ,vd3 , tvd) */ vd1.vendor_record_seq_no,
tvr.checksum, tvr.rownumber, tvr.transaction_type, 'U'
FROM vendor_data vd1, vendor_data vd2, vendor_data vd3,
(SELECT rownumber, MAX (DECODE (control_column_seq_no, 91150, original_value, NULL)) AS value1,
[code]...
Right now used tables has the following number of records-
SELECT COUNT(*) FROM vendor_data --292890442
SELECT COUNT(*) FROM temp_vendor_data --0
SELECT COUNT(*) FROM temp_vendor_record --0
This query is part of an application, but consuming too much of temporary tablespace (68 GB allocated). I found it out by using query below:
select * from v$session a, v$sql b
where a.sql_id=b.sql_id
and status = 'ACTIVE'
I am not sure, why this problem is occuring.
How do i find a particular SQL or a set of SQL's which are excuted against a table (user identified table) that is either a very frequently executed query against that table or high impact SQL against that table? I am currently looking through the AWR reports to go through all the queries but i was wondering if there are any dictionary views where we can find this info from?
View 2 Replies View RelatedThe scale of the tests that generate the following scenario is not huge right now, only 50 users simulated (or you can think of them as independently running threads if you like). But here is the crunch, the queries generated (from generic transaction layer) are all running against a table that has 600 columns! We can't really control this right now, but this is causing masses amounts of IO (5GB per request) making requests queue for disk availability (which are setup RAID 0/1); its even noticable for as few as 3 threads.
I have rendered the SQL on one occasion to execute in 13 seconds for a single user but this appears short lived as when stats were freshly gathered it went up to the normal 90-120 seconds. I've added the original query to the file, however the findings here along with our DBA (who I trust implicitly) suggest that no amount of editing the query will improve the response times, increasing the PGA/SGA (currently 4/6GB respectively) will only delay the queuing for a bit and compression can work either. In short it looks as though we've hit hardware restrictions already for this particular scenario.
As I can't really explain how my rendered query no longer takes 13 seconds, it's niggling me that we might be missing a trick.So I was hoping for some guidance on possible ways of optimising these type of queries against such wide tables, in other words possibilities that we haven't considered...
Attached is the query and plan.
How can i check if paging happening while running the query. As i have 4gb of PGA target but the query is taking long time in parallel and has hash join.
how to check paging in 11gr2
Our application servers will be running a SELECT which returns zero rows all the time.This SELECT is put into a package and this package will be called by application servers very frequently which is causing unnecessary CPU.
Original query and plan
SQL> SELECT SEGMENT_JOB_ID, SEGMENT_SET_JOB_ID, SEGMENT_ID, TARGET_VERSION
FROM AIMUSER.SEGMENT_JOBS
WHERE SEGMENT_JOB_ID NOT IN
(SELECT SEGMENT_JOB_ID
FROM AIMUSER.SEGMENT_JOBS) 2 3 4 5 ;
[code]....
Which option will be better or do we have other options?They need to pass the column's with zero rows to a ref cursor.
How can we check completion status for running sql query. i.e. how much % completed
SQL> begin
2 delete from gsmcrmdw.wc_loy_txn_f_aa
3 where integration_id in
4 ( select integration_id
5 from support_olap.recover_wc_loy_txn_f_953to955
6 );
7 commit;
8 end;
9 /
Is there any way i can Get how many rows are processing with UPDATE statement while the Update statement is still running.
View 2 Replies View RelatedAfter Migrating from 11.1 to 11.2 SQL Statements are running for a long time. Our DBA told that they don't have any execution plans for the SQL Statements in 11.1
I don't want to rewrite the SQl Statement as this is working fine in 11.1. Our DBA conveyed us that they are using DBMS_STATS.AUTO_SAMPLE_SIZE for Schema Level.
But we have planned to generate DBMS_STATS.GATHER_TABLE_STATS Estimate Percentage ==> 100 for only the tables that are used in SQl Statements.
Of course we can change the parameters.. But we are afraid it may have some side effects.
An user is running some queries and that's making database hang. I want to view what queries this user is running. Can this be done by session auditing turning on?
View 13 Replies View RelatedI ran one long running update statement in my sqlplus session, where it took hours together since we have millions of rows on the table.lock the system and left the office , the next day I found my system is rebooted, hope the session would have performed the long running update statement.
Now, I need to issue a commit for the session, since my system is rebooted I don't have opened session with me. so, How to issue commit to the session, which I have issued long running update statement.
I have a problem. I have created a report that will list out details of checks using Report Builder. I use XML Publisher to register a template for the report. When running the program through concurrent request, the output will come in pdf format but are not in order.I have add 'Order By' statement in my sql scripts in report builder. Its working fine if test in report builder but not in concurrent program.
View 4 Replies View RelatedLooking 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?
MY DB Version: 10.2.o
OS: Windows Server 2003
I am trying to import on table which i have the export dump file which i take using expdp previously when i load that table on the same host
by using below command:
expdp scott/tiger@db10g tables=EMP,DEPT directory=TEST_DIR dumpfile=EMP_DEPT.dmp logfile=expdpEMP_DEPT.log
after that i zip that dump and move it to external usb and now i need that table i copy that table and unzip that that dump
Command i am using to do the import is :
impdp scott/tiger@db10g tables=EMP,DEPT directory=TEST_DIR dumpfile=EMP_DEPT.dmp logfile=impdpEMP_DEPT.log
But the query of import is still runing even not showing any amount of rows to be imported.
i already make the tablespace in which the table was previosuly before dropping but when i check the sapce of tablespace that is also not consuming one error i got preiviously while performing this task is:
Connected to: Oracle Database 10g Enterprise Edition Release 10.1.0.2.0 - Production
With the Partitioning, OLAP and Data Mining options
Master table "CDR"."SYS_IMPORT_TABLE_03" successfully loaded/unloaded
Starting "CDR"."SYS_IMPORT_TABLE_03": cdr/********@tsiindia directory=TEST_DIR dumpfile=CAT_IN_DATA_042012.DMP tables=CAT_IN_DATA_042012 logfile=impdpCAT_IN_DATA_042012.log
[code]....
i check streams_pool_size it will show zero and then i make it to 48M and after that
SQL> show parameter streams_pool_size;
NAME TYPE VALUE
-----------
streams_pool_size big integer 48M
But still it takes time
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?
I need to add some kind of tracing in oracle 11g on linux when oracle starts and stops - as at times oracle takes a long time to start.
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