Re: Q:Table Fragmentation. How do I reduce it?

From: jan.coekelberghs_at_ping.be (Jan Coekelberghs) >>   Jan quoted:
From "Advanced Oracle Tuning and Administration" : "Extents are often blamed for performance problems; however, their impact on performance is minimal and can be completely avoided. In fact, careful use of extents can improve your response time by distributing your I/O operations across multiple devices...".
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I just want to make sure that newer DBA's understand that there is a huge difference between a table in 10 extents on one disk and a table in 10 extents accross 10 disks. An out of context quote is a dangerous thing when distinctions like this are not understood. Also as previously explained well on this thread, extents size matters in determining if multiple extents adverserly affect performance. Size them correctly and they will ususally not be a performance problem so 10 extents on one disk may or may not be a problem depending on how and why the table got to be in 10 extents. (Ten is actually a fairly small number, but it works well for the point I am trying to make)

Mark Powell -- Oracle 7 Certified DBA
- The only advice that counts is the advice that you follow so follow your own advice - Received on Thu Mar 19 1998 - 00:00:00 CST