SSD usage

  • From: "Storey, Robert (DCSO)" <RStorey@xxxxxxxxxxxxxxxxxx>
  • To: Oracle L <oracle-l@xxxxxxxxxxxxx>
  • Date: Wed, 16 Dec 2015 14:54:16 +0000


I've been reading multiple docs on SSD/HDD and the benefits within an oracle

If I am reading this write, for an OLTP system, the SSD/FLASH will provide
excellent random read/write abilities.

But folks seem contradicted on using the SSD for the Redo logs. Some say its
best practice, others say it does not buy you anything.

I have a 24/7 OLTP application that generates a modest amount of redo. My
overall DB is about 95 gigs, I generate about 600megs of redo in a day (10meg
files, switching every 30 or so). My system is getting to end of life, and I
see more log_file_sync waits, and buffer busy waits. I suspect my I/O
subsystems are getting worked hard. My top waits appear to be sequent file
reads and scattered reads, log file sync, and buffer busy.

What's the general verdict on using SSD for the data files? Best idea for
redos? My thoughts there are separating them to different drives, ie, two
separate single disks, with a group member on each disk.



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