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How do you tune a query using explain plan?
taraldesai
- Feb 23rd, 2009
It's just an overview of the query which tell us how this query is going to perform. But it's not actual. In most cases it's actual but it may be changed while at run time due to some fact...
Mad Hatter
- Nov 4th, 2008
Explain plan shows steps Oracle will be following to execute your query.This steps are: A) Plan steps with no children: A step in the plan with no dependents is a leaf of the tree (steps 6,7, and 9 ...
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Why we do use very small size of RAM compairing then HARD DISK?
prashatt
- Jun 24th, 2008
RAM means Random access memory, which is used as a temporary memory space to load Operating system kernel, driver modules and services needed on the system. Whenever you switch off the system all the ...
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It is possible to use raw devices as data files and what is the advantages over file. system files ?
Yes. The advantages over file system files. I/O will be improved because Oracle is bye-passing the kernnel which writing into disk.Disk Corruption will be very less.
prashatt
- Jun 24th, 2008
Raw devices are controlled by the database engine so the OS kernel can be bypassed when using raw devices. System files reside on filesystem, filesystem is addressed by the kernel. So everytime a data...
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What is advantage of having disk shadowing / mirroring
prashatt
- Jun 24th, 2008
Disk shadowing or mirroring is done either using a software or a hardware utility called RAID. Disk shadowing enables another disk to take-over from a failed hard disk avoiding any downtimes. Generally Hardware fial-overs are enabled on all servers.
balu
- Oct 8th, 2005
Instead of taking seperate backups mirroring always helps taking backup simultanuesy.
