I am using oracle 10g. I have created two schema/user (let's assume produser for production and devuser for development) and allocate same table space let's say "prod" and both schemas/users have some data stored in same tablespace/datafile so here my problem is first, if I drop one schema/user then related tablespace will automatically cleared or not?, if not then how can we reclaim of dropped schema/user tablespace without dropping tablespace/datafile? if you have any please suggest "How"? It will be very helpful.
Thank you!
You can think of a tablespace as being synonymous with a disk partition on your PC. Lets say you bought a 500G disk and partitioned it into 300G for C: drive, and 200G for D: drive.
When you fill your C: drive with files and then delete those files, there is now plenty of room C: drive for new files but only on C: drive. Deleting files on C: drive did not mean you get to use any of that free space for D: drive.
Tablespaces are the same. Space you free up in a tablespace can be reused by other objects (new or otherwise) in that same tablespace.
If you want to give that space that you just freed up to a different tablespace (either an existing one or a new one) then this does not happen automatically. You might be able to do something like
alter database datafile '...' resize <some smaller value>
on the tablespace you just dropped objects from, which would mean it would free up space at the OS level, which would then be allocated to something else (database or otherwise). I say "might" because even if the tablespace is 99% empty, if the remaining objects are located at (say) the beginning AND end of the file, then you can't resize the file smaller than the logical high water mark of space utilised in the file.
Related
On Oracle 12c, is the content of each datafile belonging to a single tablespace the same?
If yes, is it because of performance or backup purpose thus recommanding us to store each datafile on different drives?
If no then why would we create multiple datafiles for a single tablespace when we can autoextend each datafile?
No.
The idea of multiple datafiles supporting a single tablespaces is to be able to use striping. This ofcourse only makes sense if your server has multiple physical storage devices that preferably also have their own io interface.
À table will be in the tablespaces and can allocate space in all available datafiles. So the table data can be in all datafiles.
If your io system does not consist of multiple physical devices you might as well use a bigfile tablespace that just has one big datafile. In older releases this was a restore nightmare because the backup and restore was performed file by file.
I have a friend who has a website and asked me for help.
I often use MySQL databases but never Oracle databases.
And unfortunately he has an Oracle database, so I can't find a solution.
The available disk space is slowly decreasing... I delete a lot of lines from the table but that doesn't solve his problem.
The database continues to take up disk space slowly.
I read that LOB files do not return disk space, even if you delete data.
How can I reorganize LOB files easily with a simple request?
(or/and) How can I recover disk space on Oracle?
SELECT DISTINCT VERSION FROM PRODUCT_COMPONENT_VERSION
12.1.0.1.0
The BLOB column exists within the table blocks along with data even after deletion. It is only marked as unused. You can use the following command to free up space from the BLOB table:
ALTER TABLE <YOUR_TABLE_NAME> MODIFY
LOB <LOB_COLUMN_NAME>
( SHRINK SPACE );
Now, Table must have released some space and it is now available to be used within the tablespace.
Further, you can just alter the data file and reduce the size of the data file accordingly to free up space from Disk. (Note: Space allocated to the data file will not be automatically reduced. It must be done manually)
Cheers!!
I have created the datafiles in an external hard disk for a particular db . When the hard disk is connected I am able to run the server without any issues . Now when I remove the hard disk and try running the server , it throws error saying
NO DATAFILE PATH Found
This is because the path of datafiles is in the external hard disk .
Now, is there anyway i can run the server against the same database even if the hard disk is not connected ?
Assuming the real question is how to get the external disk datafiles onto the local system, have a look here :
https://docs.oracle.com/cd/B28359_01/server.111/b28310/dfiles005.htm
Outline steps:
Procedure for Renaming Datafiles in a Single Tablespace
To rename datafiles in a single tablespace, complete the following steps:
Take the tablespace that contains the datafiles offline. The database must be open.
For example:
ALTER TABLESPACE users OFFLINE NORMAL;
Rename the datafiles using the operating system - in your case COPY the files from the external disk to local disk
Use the ALTER TABLESPACE statement with the RENAME DATAFILE clause to change the filenames within the database.
For example, the following statement renames the datafiles /u02/oracle/rbdb1/user1.dbf and /u02/oracle/rbdb1/user2.dbf to/u02/oracle/rbdb1/users01.dbf and /u02/oracle/rbdb1/users02.dbf, respectively:
ALTER TABLESPACE users
RENAME DATAFILE '/u02/oracle/rbdb1/user1.dbf',
'/u02/oracle/rbdb1/user2.dbf'
TO '/u02/oracle/rbdb1/users01.dbf',
'/u02/oracle/rbdb1/users02.dbf';
Always provide complete filenames (including their paths) to properly identify the old and new datafiles. In particular, specify the old datafile name exactly as it appears in the DBA_DATA_FILES view of the data dictionary.
Back up the database. After making any structural changes to a database, always perform an immediate and complete backup.
I want more file system space. so I truncate all tables in oracle ,but the higher water mark still so high, I shrink my tables; I had google it ,shrink only cut dowen the space higher than hwm It reduce some space, but It help less.and I find that tablespace is only used 1% space.how can I free the space in my file system.
Finally, We find that we get a droped table in the end of the segment, so the hwm is high, we purge the tablespace , then alter table datefile resize.
One way to do it is to export the database at user level using exp. Then drop and recreate the user. Then do an import. This should free up some space.
You can also use alter database datafile to reduce one of your datafiles (these are the physical files on your hard drive used by the db).
There is a great overview of how to reclaim datafile space in this article. TL DR - export, drop user, alter datafile, import.
http://oracle-base.com/articles/misc/reclaiming-unused-space.php
if I have a datafile in a directory and it is getting too big for the directory what command in Oracle can I use to move that file, or do I make another datafile into another directory?
ALTER TABLESPACE
users
ADD DATAFILE
‘/ora01/oracle/oradata/booktst_users_02.dbf’
size 100m
You can do either. Adding a datafile is simpler as it can be done online, with the command you've shown. As long as you don't mind having the datafiles spread across directories, and you don't need to remove the filesystem the file is currently on, this ought to be fine for you.
The documentation explains how to relocate a datafile. I won't quote the whole thing, but essentially, with the tablespace offline, copy the datafile(s) to another disk then update the database control file (and data dictionary) to point to the new location with an ALTER TABLESPACE...RENAME DATAFILE command, then you can bring the tablespace back online.
As the documentation also mentions, make a backup of the modified database. Once the tablespace is using the new copies of the files you can delete the old ones from the filesystem - carefully, make sure you're working on the unused copy! - to free up the disk space.
Another option is to create a new tablespace with its datafile(s) on a larger filesystem and them move all the objects into that, then drop the original. The tablespaces remain online, but access to the objects being moved will be temporarily blocked; if the objects are large that may be a significant issue and much slower than moving the datafiles.