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17

You need to recreate the control file This post by Kaunain Ahmed describes the necessary steps: do: alter database backup controlfile to trace; extract the "create controlfile" command from the background-dump-destination tracefile. shutdown the DB. Change the DB-Name in your init.ora and change the init.ora Change the SID in the ...


12

The real answer will be in the PostgreSQL logs, in /var/lib/pgsql/data/pg_log. However, before you take any action: It is vital that you take a file system level copy of your database before attempting repair if any of your data is valuable to you. See http://wiki.postgresql.org/wiki/Corruption . You must copy the whole data directory. On Fedora that's ...


11

All Data is InnoDB This is what will give you an exact point-in-time snapshot of the data: mysqldump -uuser -ppass --single-transaction --routines --triggers --all-databases > backup_db.sql --single-transaction produces a checkpoint that allows the dump to capture all data prior to the checkpoint while receiving incoming changes. Those incoming ...


10

Since 9i dbnewid utility (nid) can be used to change database name (and DBID if required). If database name being changed only then resetlogs is not required: 1. startup database in mount mode shutdown immediate startup mount 2. run nid to change database name: nid target=sys/syspassword@dbtns dbname=newname setname=YES 3. shutdown and ...


8

According to the MySQL Documentation, the InnoDB Buffer Pool is set to 128MB by default in MySQL 5.5. You can show how much of the InnoDB Buffer Pool is in use and reserved as follows: SELECT BufferPoolUsed BytesUsed, (BufferPoolUsed / power(1024,1)) UsedKB, (BufferPoolUsed / power(1024,2)) UsedMB, (BufferPoolUsed / power(1024,3)) UsedGB, ...


7

Migrating between two very different DBMS requires a lot more than just migrating the data. But migration of the data is usually the easiest part. The way that I have tried, which is free and I can confirm that it works: create a mysql schema only dump Adjust the SQL using a text editor and a lot of search and replace run the converted SQL in Postgres ...


7

I don't think it's a matter of performance but of management. With separate file per table, you can store different databases in different storage devices for example. You can deal with the case of very large databases in file systems that can't handle big files (at least postpone the problem until one table reaches the file size limit). You don't have ...


6

Yes, you can and it is quite easy too. In Oracle, the ORACLE_SID is just the name for the Oracle Instance and has not very much to do with the DBNAME. A database with the name PROD, can be served using Instances with any valid name. There is no direct connection between the SID and the DBNAME. This connection is made using the parameters. The parameter ...


6

Memory usage in linux in general and for Postgres in particular is a pretty complex subject, a good starting point is Bruce Momjians blog covering the subject and the usage of smem. It is well worth following the links in Chris Seibenmanns blog on the subject.


6

1a. Warm standby is a "live", incremental backup fed with complete blocks of changes (wal segments) 16 mb each, that are send to the standby node once they're filled. You cannot query a warm standby node. 16 mb of changes (by default) can mean a lot of transactions, should the master fail, they'll be lost. 1b. Hot Standby. (also a "live" incremental backup) ...


5

I would be very surprised if there was a generic tool for this - how would it "know" what is sensitive data and what wasn't? For example it would need to examine all your data and recognize all possible formats of credit card number, phone number, postcode, email address, and whatever other data is considered sensitive. It would also need to be smart about ...


5

Your database is unhappy. Login to your Linux box as the DB owner user (usually oracle), restart it & then do the following to recreate the broken data dictionary objects: sqlplus / as sysdba @?/rdbms/admin/catrepr.sql @?/rdbms/admin/catrep.sql @?/rdbms/admin/utlrp.sql Restart the database once done. This is an unusual situation to be in - Has ...


5

There is no reason why Oracle would perform badly on Ubuntu (though Oracles OEL kernel has some Oracle-specific optimisations), it's all about enterprise support. Certification is an expensive and time-consuming task, as is training support workers in each flavour of Linux - that's why the RDBMS is only officially supported on a select number of releases.


5

PROBLEM In MySQL 5.6, ibdata1 includes 5 InnoDB in the mysql schema. mysql> select table_name from information_schema.tables -> where table_schema='mysql' and engine='InnoDB'; +----------------------+ | table_name | +----------------------+ | innodb_index_stats | | innodb_table_stats | | slave_master_info | | slave_relay_log_info ...


5

"no space left on the device" could also mean that the partition is out of inodes. Use df -i to check inode usage. Edit: Each file, directory, and symbolic link requires one inode. So the idea is to remove some files from the / partition. It doesn't matter how large the files are. You can of course just pick some files on the partition and move them to ...


4

I have administered both MySQL and DB2 database systems. In general, I'd say that DB2 requires more memory and more administration. But sometimes, you can use DB2's sophisticated features to perform queries which are much more efficient. About memory and administration: DB2 is not very good at making good use of RAM. Either you spend a lot of time ...


4

Memory can help you by caching and thus reducing I/O. However, that won't reduce CPU usage which is your problem. This is an unusual bottleneck, as CPUs are insanely fast for most database work and I/O tends to be the bottleneck. In your case, it is even more inusual, because you have 16-cores and VPSs tend not to have great I/O performance. First of all, ...


4

The buffer pool is used by MySQL for caching InnoDB data and indexes in memory. It is not the total memory used but your MySQL DB If your InnoDB tables are that small 128MB is more than enough and effectively all InnoDB tables will be treated as in-memory tables. The 128Mb is a limit of how large the buffer can be and it is only filled when needed. You can ...


4

Oracle has an alert log which should tell you when and why it shut down. Depending on how the database was configured, that will be under a directory identified by either the diagnostic_dest or background_dump_dest parameters, and will be called alert.xml or alert.log (in previous versions). If you're running it, you can get information from Enterprise ...


4

This is my reason for never NOT using innodb_file_per_table: Without file per table, the ibdata file never compresses or shrinks or lessens in space ever. Not when you delete a row, drop a table, or a database. 2GB of data can become a 20GB file in no time if you have an active queuing system. Let's say you want to make a backup of your current 1GB table ...


4

If you only need to run SQLPlus, grab "Instant Client Package - Basic" and "Instant Client Package - SQL Plus: Additional libraries and executable for running SQL Plus with Instant Client" from http://www.oracle.com/technetwork/topics/linuxsoft-082809.html & install them. oci.dll is a windows file, so I have no idea what could be achieved by installing ...


4

Your risk is data loss, not data corruption. An ACID platform guarantees transactions are atomic, consistent, isolated, and durable. With asynchronous commits, you give up "durable". For your application, that seems a defensible decision. If you have some transactions that need to be durable (new user registrations?) you can have that, too. PREPARE ...


4

I think the permissions are correct because otherwise you wouldn't have gotten here. My guess is that a modification you have made has caused the problem. This is particularly the case given that it is a segmentation fault. What you really need to do is look at the call stack at the time the core was dumped and see if you can isolate where in the code ...


4

+1 to @RolandoMySQLDBA of course for another valiant answer. But more to the point of your question: ...will [there] be any reading problem while I copy a MyISAM table files (the .frm, .MYD, MYI) and it gets a [write] transaction. YES. You can't get a consistent backup even for a single MyISAM table unless you do some type of locking to prevent ...


3

Had to do it recently and since it would have taken too long to look for a tool and be able to do stuff with it, I did it per hand with vim and substitution-foo replace INT NOT NULL AUTO_INCREMENT (or anything like this) with SERIAL change everythig string related into a TEXT (no speed difference in using TEXT, VARCHAR, or similar) get rid of those f***ing ...


3

In General if you have the credentials for accessing MySql from Machine B. You should have MySQL user name , host name and Password.Then You can write the Command for taking backup On Machine B Write mysqldump -h Your_host_name -u user_name -p password --all-databases > backup.sql If You Face issues there may be some network issue try some things as ...


3

I had a similar problem. Virtual disks kill performance. Try to get as much data into memory as possible. I eventually put the disk intensive VM's onto its own RAID stack. Most people in OIT do not recommend putting disk intensive applications into a VM because of this reason. You also didn't specify which VMWare product you are using. ESXi was released for ...


3

For JDBC based tools such as Squirrel you should try to use (even with Oracle8i) a 9.x or even a 10.x driver (not sure about the 10.x though). Maybe they give better performance. Somewhere on the JDBC download page of Oracle there is a compatibility Matrix that shows which driver version is compatible with which database version. Another cross-platform ...


3

You need to have different keys for the IPC entries in the two configurations, e.g. KEY = EXTPROC10 and KEY = EXTPROC11. IPC uses memory and semaphores etc. that may be shared across the machine, so you need to provide a way for the instances to be differentiated. Also make sure you're starting the listeners explicitly, e.g. lsnrctl start listener10, and ...


3

Why using innodb_file_per_table? Because it is easier to manage individual since it can be done at the file-level. This means that even if the server is down, you can still copy data by copying the table files whereas using a shared table-space means either copying everything which can be unnecessarily massive, or finding some way to get the server ...



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