The oracle-l mailing list made me try a new tool, created by David Litchfield. It’s called DDLDUMP V. 0.1 and extracts DDL from redo logs or archived redo logs, the output format is XML. Since it’s a windows .exe file for now, I had to use wine to test it, but it works flawlessly, and […]
Tag: Oracle
Oracle srvctl does not remove EONS despite it’s documented (PRKO-2013)
srvctl in Oracle Grid Infrastructure 11g Release 2 has at least one discrepancy between docs and functionality. I saw EONS consuming lots of memory in a non-database grid installation, and wanted to get rid of it. (The eONS is used by Oracle Enterprise Manager to receive notification of change in status of components managed by […]
Oracle IMPDP, ORA-1555 and UNDO_RETENTION
Many topics are to be found on the web about IMPDP and UNDO_RETENTION. This one will become a more theoretical one, around the central question: Why, please why does a huge IMPDP fail with ORA-1555 if there is too less UNDO_RETENTION configured? Like so often, these questions come from a problem. I had to impdp […]
Oracle Grid Infrastructure: UDEV fixing ORA-15081: failed to submit an I/O operation to a disk
If you plan to install Oracle products, be prepared for surprise of random kind. 🙂 The new Grid Infrastructure is no exception of this rule: I tried to install it on a SuSE Linux Enterprise Server (SLES) 10. Quick facts about the setup: SLES 10 SP 2 64bit Oracle Grid Infrastructure 11.2.0.1 x86_64 all devices […]
Oracle Grid Infrastructure 11gR2: How to clean up to repeat root.sh
To clean up a tilted installation of Oracle Grid Infrastructure isn’t that intuitive. I had to do it today, and this is my collection what to do and what to read. It’s made for repeating root.sh, that’s not allowed to run twice or more times without cleaning up in between. So first have a look […]
Oracle: How to create a good execution plan
Sometimes you simple need to know whether a statement is fast or not, or why it is slow. (Sadly, it seems like virtually nobody wants to know why a statement is fast, but that’s another story…) Do not use EXPLAIN PLAN in such cases, it does not (can not) deal bind variables right. I’ve got […]
Oracle 11g Adaptive Cursor Sharing does not work with PL/SQL?
Recently, there was trouble in the air. I migrated a database into 11g to enjoy adaptive cursor sharing, but it did not adapt cursors. In the trouble shooting process, I discovered the following: Bug 8357294: ADAPTIVE CURSOR SHARING DOESN’T WORK FOR SQL FROM PL/SQL Nice one. A short quotation from the bug text: PL/SQL has […]
Talk about Database Technology Basics at Berufsschule Wiesau
Once again, I will talk about an IT topic at Vocational School (Berufsschule) Wiesau. This year, it’s Basics of Database Technology (Grundlagen der Datenbanktechnik) for 11th and 12th-graders, who will become certified IT specialists for software development soon. Their certification is called “Fachinformatiker der Fachrichtung Anwendungsentwicklung” in German. The paper for the talk is available […]
Oracle Technology Day Storage Optimisation – Impressions
In January, I’ve bee rather busy, so the blog was left alone. No sense in blogging just to blog. Now some content. I attended the Oracle Technology Day – Storage Optimisation in Bonn, Germany. It was a nice event, lots of information, a bit commercials, excellent catering. But this is a technical blog, let’s talk […]
Oracle 11g: Password expired, account locked – unwanted!
Hi, it’s old news, but oracle 11g expires passwords after 180 days, and locks you out if you mistype your password 10 times, and most DBAs don’t like that. It’s unsecure, but for client-server-applications a locked account is no single-user-annoyance, it’s a downtime killing SLAs, nerves and – hopefully not – DBA jobs. So just […]
DOAG Konferenz 2009: Impressions Day 3 (final)
Thursday 19th was the last day of DOAG Confernce 2009. Compared with the second day, the program was much more dense: For my (DBA) profile there have been several hours, where more that one talk would have been appropriate. This list is, what I collected during the day. […]
DOAG Konferenz 2009: Impressions Day 2
As promised, today my impressions of yesterday (confusing, I know). Clarification: This is about Wednesday, November 18th. I’m still at DOAG Conference 2009 in Nuremberg. Wednesday was a silent day for my interests, especially at noon there have been less talks being of interest, but maybe they have done something for my general knowledge… So […]
DOAG Konferenz 2009: Impressions Day 1
These days, the DOAG Conference 2009 happens in Nuremberg, Germany. First day was yesterday, Tuesday November 11th 2009. This is a machine-readable copy of my scratchpad, coming from the different talks I attended. Sun Oracle Database Machine Exadata 2: The “Quarter Rack” (consisting of 2 Servers and 3 storage nodes) sounds interesting. 11gR2 has some […]
Oracle 11gR2 ASM / ACFS: A first benchmark (poorly)
Hi folks, since Oracle 11g Release 2 is out now, I had to test one of the most-missed ASM features: the ASM cluster file system ACFS. My Setup: Two VMware nodes with 2 CPUs and 1,5GB of RAM each Oracle Enterprise Linux 5.3 x86_64 Four virtual cluster disks from the ESX server, 10GB in size […]
Oracle 11gR2 ASM: Changed permission policy (ORA-15260)
Did you recently see the new error ‘ORA-15260: permission denied on ASM disk group’ in your ASM administration? Maybe you are still connected as SYSDBA, old habit from 10g? A quick citation from the Oracle Docs: The SYSOPER privilege permits the following subset of the ALTER DISKGROUP operations: diskgroup_availability, rebalance_diskgroup_clause, check_diskgroup_clause (without the REPAIR option). […]
Oracle: Executing an OS command from PL/SQL – ICMP ping from database
Executing OS commands from SQL or PL/SQL is easy as long as you are in SQL*PLUS – just do a host command. But I must confess, that this is a really useless hint. 🙂 Much more interesting is to execute an OS command with a DBMS_SCHEDULER job, but this is not possible in every case, […]
Oracle: Tracing of another session
I simply love 10046 level 12 traces. I described session tracing based on a logon trigger quite earlier, but some situations in real DBA life need this trace event switched on for a session other than my own AND for a short peroid in time (with no need for the connected user to log out). […]
Oracle Explain Plans or Execution Plans: Guess or Reality?
Oracle finally desupported the rule-based optimizer with version 10g. Since 9i, users are good adviced to make themself familiar with the cost-based-optimizer (CBO). In order to understand what happens with your statement after parsing with CBO involved, and to be able to tune your queries, displaying, understanding and optimizing explain- or execution plans is essential. […]
Get Oracle User DDL with dbms_metadata
Sometimes you have to recreate a user in a DB, and you like it to be the same as before again. To have its DDL at hand is usually rather convenient. DBMS_METADATA is a great toolbox to get it, my example is just a short but hopefully useful excerpt of its possibilities: set long 200000 […]
Oracle 11g JDBC driver hangs blocked by /dev/random – entropy pool empty
On a headless (=without console) network server, the 11g JDBC driver used for (java) application connect may cause trouble. In my case, it refused to connect to the DB without any error, trace or log entry. It simply hung. After several hours, it connected one time, and freezed again. Remote debugging done by the development […]
Creating Oracle AWR reports quicksheet
For comparing, classifying, benchmarking and forecasting databases, Oracle’s Automatic Workload Repository (AWR) is neat. (But remember! You will need a diagnostics pack license for that as described here and here – if you need a free technology for performance monitoring, consider using Craig Shallahamer’s OSM toolkit.) This post simply describes the package calls to create […]
Oracle DB: Automatic tracing for all sessions of a user
Hi, SQL tracing is nice to find out details about several issues. But there is no out-of-the-box solution to enable tracing for a user, only for session- or system-wide tracing. But there’s a trick to close this gap. It’s old, but stil useful: Use a logon trigger to enable tracing for all sessions of a […]