Slow Database - V$session Has Lots Of Active Sessions With 00 As Sql-address?
Oct 1, 2012
Server:
Windows 2008 R2 x64
Oracle Database 11g Release 11.2.0.1.0 Standard Edition
I recently applied the Oracle® Database Server Version 11.2.0.1 Patch 16 I have several databases running on this box with the same application.Since then I've had lots of customers complaining about slow systems. The server has plenty of RAM availableI also have several other servers all on the same versions, same patch, running the same application with no issues.
Looking at v$session there are often lots of active sessions that have a sql_address of "00". I've never seen this before and I regularly look at v$session, as you can see for below these have been running for a while. The sessions do drop off but I am at a loss as to what is happening.
select username, last_call_et, sid, serial#, user#, status, sql_address, sql_hash_value
from v$session
where username is not null and status = 'ACTIVE'
order by last_call_et desc, sid
I have a RAC on 9i and I want to know the number of active sessions that it's executing the same sql sentence.I'm using this sql but I'm not sure that this query give me te correct result.
SELECT se.inst_id,se.status,se.SQL_HASH_VALUE,se.USERNAME,substr(sq.SQL_TEXT,1,50) SQL,count(*) FROM GV$SESSION se, gv$sql sq WHERE se.STATUS='ACTIVE' and se.username is not null
I have had the following problem open with Oracle support since March 2011 (8 months), and still no resolution.
When I export all our schema's on Sunday night it takes about 1 hour 50 minutes. When I export the same schema's on any other night it takes 7 hours. The only difference is that on Sunday at 4:00am we drop all connections in the connection pools and reestablish new connections. Then 19hours later on Sunday at 23:00 we perform the exports which only take 2 hours to complete.
I have also tried recreating the connections in the connection pools during the week, and the exports have then only taken 2 hours to complete. But the following night after the connections have been used during the day, the exports again take 7 hours. So it appears the export speed gets significantly slower when there are many open connections that have been used and not closed.
From the stats pack report I found 2 SQL statements internal to the export command, that had an order of magnitude in difference when looking at the elapsed execution time between the fast export, and the slow export (see below).
How to speed up the exports without having to drop and recreate the database connections in the connection pools each night.
FAST: elapsed_time: 430.90 executions: 161,388 Module: exp@Oracle1 (TNS V1-V3) SELECT COLNAME, COLNO, PROPERTY, NOLOG FROM SYS.EXU10CCL WHERE CNO = :1 ORDER BY COLNO
I use the following export command for each schema: $ORACLE_HOME/bin/exp user/pass file=somefile.dmp owner=$SCHEMA log=somelog.log buffer=9000000
I have an Oracle Standard edition 11.1.0.7 database on 64bit Linux with a 7GB SGA. I currently export (I use exp not datapump because datapump is a lot slower and we can't use parallel processing features of datapump on a standard edition database) approx 200 schema's each night. The export normally takes 1 hour 50 minutes which is approximately 2 schema's exported every minute. When the exports run slowly each export takes almost 2 minutes to complete.
The database has about 20 GB data and 50 GB indexes. The database has also approx 500 connections via toplink connection pools from 8 application servers.
11.2.0.3 EVENTS: Null(blank) or called a 'null event' See link. Checked the docs. I don't see anythingI think a null (blank) is for an idle wait since per the V$ACTIVE_SESSION_HISTORY spec these are not record. Am I correct?What is a 'null event'. I see a paper from Oracle magician dating to 9i that says this is an 'oracle goof'. Descriptions of Wait Events
I´m monitoring a 11g database with OEM. I have a couple of questions regarding the Average Active Sessions chart:
- What does the line 'CPU core' means? The DB is running in a virtual server with 8 CPUs. However, the line 'CPU core' is in 1. Does it mean that Oracle is just using 1 CPU? - What represents the '99th percentile' line? The chart shows several sessions above that line, something is not working well, isn't it?
Mistakenly I added lot of datafiles with autextend on option.. I realized later and then tried to resize the datafiles to a minumum space but got the below error
ORA-03214: File Size specified is smaller than minimum required.
How to resolve this problem to reclain the space back?
creating the standby database from Active database using RMAN and getting the below issue after i executed the duplicate command.
Version of Database:11g(11.2.0.1.0) Operating System:Linux 5 Error: RMAN-00571: =========================================================== RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS =============== RMAN-00571: =========================================================== RMAN-03002: failure of Duplicate Db command at 12/21/2012 17:26:52 RMAN-03015: error occurred in stored script Memory Script RMAN-04006: error from auxiliary database: ORA-12514: TNS:listener does not currently know of service requested in connect descriptor [code]....
provide any work arounds to proceed further in creating the standby database.
The script has successfully created on standby db all controlfiles and also has copied 2 data files DATA01.DBF and DATA02.DBF into the correct location. Then the errors above kicked in and stopped the rman dup process.
I am getting starting with rac environments. I need to configure a two nodes active/active with rac and I need to know if always using rac both nodes will be active or if I have to do that at some point when installing. I have reading some docs from oracle and others authors about rac and its configuration process but that is not understood for my yet.
I've got a physical standby database and I'm now licensed for Active DataGuard. I would like to automate the ALTER DATABASE RECOVER MANAGED STANDBY DATABASE DISCONNECT FROM SESSION command to be executed right after the STARTUP command so that whenever the database is started by our DBSTART script, it activates READ ONLY W/APPLY immediately after start without manual intervention. This is probably simple, but I figured I'd ask before starting to pore through documentation.....!
I was just wondering how Oracle manages multiple sessions in a database performing DML. I believe this is related to 'Read Consistency' and I tried to search for the same but could not get any satisfactory online documents.
CASE 1: user A logs in to a database1 issues select on table A and then inserts 4 rows user B logs in to databse1 issues select on table A and then inserts 5 rows issues rollback user C logs in to a database1 issues select on table A and then inserts 6 rows issues commit
How many rows can user C see in the table A when he issues select?
CASE 2: user A logs in to a database1 issues select on table A and then inserts 4 rows user B logs in to databse1 issues select on table A and then inserts 5 rows user C logs in to a database1 user B issues rollback user C issues select on table A and then inserts 6 rows issues commit
How many rows can user C see in the table A when he issues select?
NOTE: All the users are currently logged in to the same database and none has logged out.
I have a simple question about database sessions. The value of parameter "sessions" is set to 500 and the users connect to database through an application server(Jboss). There are more than 500 users connect to the database through application.
My question is, how more than 500 users can connect to the database without any issue, if we set the value of "sessions" parameter to 500?
Does version 4.2 create a new db session for each report run on a page?
The reason I ask is we have a page with 4 report regions, each querying a global temporary table that is populated in a 'Before Regions' page process. The first report displays the correct data, but the others return 'No Data Found' and it is because the Global Temporary Table has been cleared out following the first report. This did not happen in 4.1.
I know we should be using Apex Collections, and we will in future, but time is at a premium to get this live
I'm trying to set up Active Database Duplication between 2 Oracle 11g servers. Each server is identical, with the following characteristics:
- OS: Windows Server 2008 - Version: Ora11R2 (64 bit) - DB Name: orcl - Filesystem: asm (using grid infrastructure)
In addition, each server has been configured with the same sys passwords. The databases themselves were configured during installation (so the setups are about as basic as you can get.)
Now, I've done all sorts of research into how to do this. I've found plenty of good sources, but they seem to all have differences in the details.Here's what I've done so far:
- The TNSNames.ora file on each server has an entry for 'src' and 'dest' (sourca and destination) respectively - I created an entry named 'SID_LIST_LISTENER' in the listner.ora file on the source machine. However, should the sid_name in this entry refer to the source or destination machine? Or does this listener entry belong on the destination machine instead? - A lot of the examples require the setup of a new password file and spfile. Are these entries necessary if I'm using the same file structures/user names/etc. on both servers?
I have a active data guard database which is copy of my production database. can i backup the active database using RMAN? The ADG is a read only and dont know, if RMAN can backup an read only database.
We are using one software it is a test tool for verify the data base posting speed from server to client systems. In windows 2008 R2, database posting speed is very slow when compare to windows 2003 server .
Server configuration is same for both servers ( RAID 5 , RAM 4 GB) how we can improve writing performance in Oracle
I'm trying to set up active database duplication between 2 Oracle 11g servers.
Both servers were set up with identical configurations (same directory structures, file systems, SIDs, and sys passwords.) Both oracle instances were created at the time of software installation.
Here is how things are configured: - Version: Ora11gR2 - Oracle service name: orcl - File system: ASM - OS: Windows Server 2008
I've done some research and found several sources giving instructions on how to set up active database duplication (including a blog engry by rajabaskar on this site), but each site seems to have different details.
So, here's what I have so far:
- Set up entries in each TNSNames file... each has an entry 'src' and 'dst' (for source and destination)
- A new listener has been added on the source machine
- on the destination machine, run the 'oradm' to create a new SID. However, is this really necessary? Since the service names are already the same
- I'm also supposed to create a password file on the destination machine using orapwd. Again, is this necessary, if I'm using the same passwords on both machines?
Am I on the right track? Should I have created an actual database on the destination machine or should I have started with just the software installed?
I'm checking the possibility to use Active Directory to log on the our Oracle databases. But only for dba's and developers, not application users. We use Oracle 10.2.0.4 (and soon 11g) As OS on the databaseserver we use AIX5L 5.3
Is it possible to implement Active Directory on databases running on AIX ? If it is possible, what must be done to get it to work, software ... etc ?
I have a table in Oracle with a column userid and i have a userid column in Active Directory. based on this i want to query the Network ID and update in one of the Group in the Active Directory. how to get the results?
We have quite a number of sessions in database MES (production) coming from another machine.
From v$session, the program is oracle@WID27 (TNS V1-V3). This WID27 (hostname) consists of quite a number of development databases inside. We have to trace which jobs are actually triggering this, as WID27 are not suppose to connect to production databases.
How can we tell whether the sessions came in is from dblink or from the machine itself?
we are using oracle 9i on AIX Server. When Customer were accessing the database, accidentally power was shut down. we restarted the Server,and Oracle database. all resumed successfully.
However while doing "Payments by the customer" it takes a lot of time to insert even a single payment record on database.The database is Live and our customer are very much frustrated,
Last week we have realized that a user who connects through SQL Developer(as nothing wrong found in application server logs) has made a serious change in the database which created a real mess. The user has done some mischief in some calculations by making some inserts and updates in some important tables in our production database.
How can I find which user or from which IP the change is made.
I have a RAC 48 cores on solaris. I check dbconsole when application performance is very slow and everyone complains, and I see that the main wait is cpu - also on the awr report. however when I check server cpu I see about 80% idle! so how can I make oracle use more cpu power instead of waiting for it? I don't think that parallel is an option here because I can't change the application code.
