Hot answers tagged oracle
4
The short answer: you cannot add column to a table at a specific position.
When you add new columns they always go after the existing columns. You have to re-create your table with new definition to place a column to a position you need.
You can however create views with columns positioned arbitrarily based on your existing table, and then query or update ...
2
As Ste says in his answer, temp tablespaces should be fine for this, so global temporary tables and other transient storage would be good.
If you wanted to use permanent tablespaces then you could DROP TABLESPACE my_tablespace INCLUDING CONTENTS AND DATAFILES CASCADE CONSTRAINTS before system shutdown if the storage was going to be lost, and recreate on ...
2
Oracle does not record checkpoint information in tempfile. So, for the tempfile:
Oracle is able to start even if tempfile is missing. You will get a message in the alter log and you should recreate tempfile.
No backup is taken of tempfile so it's safe to loose it
There is no need to trick with any storage parameter for tempfile if resides on ephemeral ...
2
Depends how much data you need on the second database. Solutions are not to save query results on a second DB but duplicate data for querying on another DB. Basically the following techonologies:
Oracle Streams: it is a replication from one database to another one. Can be done by table or by schema.
Oracle Active Dataguard: it is basically a standby DB ...
2
RMAN only works at the block level & has no idea about the contents of a given block, and therefore cannot do this.
You need to use expdp with the query parameter:
expdp phil/phil directory=myexportdir dumpfile=yourtable.dmp query=yourtable:\"where groupid in (1,2,3)\" tables=yourtable
Obviously, this isn't incremental. There's no really easy way of ...
1
An Oracle database uses two basic kinds of disk files - .dbf (data) and .ctl (control) files. You can also have .idx files (for indices). In most environments I've been in, these are located in /u01, /u02, /u03, and on, for however many /u0X's your DBAs had created.
On the other hand, many Oracle installations don't use filesystem files, they use raw disk ...
1
Here's an example of how you can do this in shell script (bash or ksh for instance). Here's simple SQL script to test, it turns off (most?) of the usually undesired output from SQL*Plus:
set feedback off
set echo off
set heading off
set pages 0
whenever sqlerror exit 4
whenever oserror exit 8
select status from v$instance;
exit
You can run it like this, ...
1
As I understand it the resizing of the high water mark requires an exclusive table lock, which in theory might not be a problem as it would be of very short duration. However if it has to wait on other transactions before it gets the lock it will block other transactions.
https://forums.oracle.com/forums/thread.jspa?threadID=2453756
However as the docs ...
1
Two solutions:
Install oracle manually the first time. Then zip all ORACLE_HOME and for future installation simply do:
Unzip oracle_home into the new home
Run $ORACLE_HOME/bin/relink all
Run ./runInstaller -silent -attachHome ORACLE_HOME="<Oracle_Home_Location>" ORACLE_HOME_NAME="<Oracle_Home_Name>"
Other solution (not my preferred but ...
1
Undo data is used to ensure ACID of the database. It supports your transaction and cannot be removed until you committed or rolled it back. Read "What Is Undo?" in Database Administrator's Guide.
You can however commit your transaction to release some undo space, but you lose the ability to roll back your changes.
If the DML you are performing requires ...
1
Can you define "corruption" and explain exactly what happened to the files?
If the data is really valuable (in which case you'll hopefully be investing a lot more in your backup and recovery to make sure that you can't lose your database and all your backups simultaneously), there are tools that may be able to salvage some of your data. Oracle Consulting ...
1
You should use export/import. On your side do:
expdp system/systempawwdord SCHEMAS=YOURSCHEMA
This will produce a file. Take it manually to you customer using CD, DVD, Pendrive. On customer site do:
impdp system/systempassword SCHEMAS=YOURSCHEMA
If the customer is using a different Oracle version, this is not a problem. You probably need to manually ...
1
Log file sync occurs when a commit is made and the redo buffer needs to be flushed to disk. The session has to wait for that to happen.
An increase in the number of log file syncs generally means that one of your developers has gone commit-happy, and is committing far too frequently -- every row, for example.
Here you probably have a process that performs ...
1
The best source for Oracle internals is generally the Oracle Concepts Guide.
In this case they have a pretty good description, including how it works as part of transaction control.
http://docs.oracle.com/cd/E11882_01/server.112/e25789/transact.htm#CNCPT039
1
In addition to what the others have said, you could keep some data in flat files and them copy the files to the ephemeral storage on startup. You could then access it using external tables. I don't know if this would be faster or better, but it is another possible use.
1
It's a bit scary that you're working on a RAC database but are getting confused between databases and instances.
The database is the set of files that store the data plus the supporting configuration files, and the instance is the set of memory allocations and processes that access them. A RAC system is distinguished by having multiple instances accessing a ...
1
Deadlock (ORA-00060) are automatically resolved by Oracle and signalled in the alter.log.
Transactional locks have to solved manually.
You can kill session from sql command line using:
SQL> alter system kill session 'sid, serial#';
This will mark session for being killed whener it's possible. Sometime kill is not immediate. IF you want and immediate ...
1
Answer is complex and involves the knowing of different Oracle concepts. I try to explain (sorry if I am going to be too wordy).
The High Water Mark (HWM) is the point in a segment beyond which data blocks are unformatted and have never been used (Oracle Concept definition). Considering that you are using ASSM (Automatic Segment Space Management)
all ...
1
The latest full client will work fine with 10g.
I have experienced similar problems using anything other than the full client, even though according to Oracle the others should work.
Just make sure that you completely uninstall all elements of the previous installs as having multiple clients/versions can create another set of problems.
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