Tag Archives: oracle 11g

Oracle DB – Compression of LOBs

We have some APEX applications for our colleagues, where people can attach files (usually MS Word documents or PDF files).  A straightforward way to implement it was to use a table with BLOB field and connect it with the file item in an upload form.  All works well,  but as times goes on BLOBs are starting to take significant amount of space.    I have been looking for some solution, how to reduce space taken by attached documents and explored Oracle 11g compression capabilities.
For LOBs 11g (Enterprise Edition)  provides new feature called SecureFiles, which also enables compression of LOB data. We have migrated our tables to use SecureFiles and saved approximately  50% of space. Continue reading Oracle DB – Compression of LOBs

Quick And Dirty Oracle Backup

I have an Oracle 11g installation running in virtual machine (under Xen). Oracle is used for APEX development and some host few local applications for our team. From time to time I need to do cold backups – to keep data around or to move them to another VM on different server, which is running identical version of oracle  and can be used as cold backup eventually.   The backup device is an USB disk with FAT32 filesystem (FAT32 was chosen a while ago for compatibility reason – to be able to attach it to almost any OS) and the disk is attached to other server. FAT32 means that there is a limit on file size, so the database backup need to be split to chunks (backup is 10-15 GB). Of course RMAN can do proper job, but since I’m no real DBA I want to have something quick ( data are not mission critical and also it is no problem to bring DB down) – so warning do not apply this procedure for important databases – no guarantee that it will work in all circumstances and you may loose your data . Continue reading Quick And Dirty Oracle Backup