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TPC-E 4K database block performanse


#1

Hello,
Last night I run TPC-E test, scale 1 8.5GB, Keying and Think Time 1-2s Unified distribution. I set 3 iterations with 20,40 and 60 user load. Test was executed on Oracle 11gR2 64bit with max memory for PGA and SGA (bafer cache and all others) set at 4,8GB od RAM with Automatic Managment. The goal was to prove that smaller block size works better for OLTP (TPC-E simulated), and I used 2K,4K,8K,16K,32K block sizes for Run1,Run3,Run5,Run7,Run9 respectively. Results confirmed 2K block as the most stable performanse block scaled on diferent user loads. 8K,16K,32K had not so good performanse which is ok for TPC-E. But i do have problem explaining 4K performanse in run 3 which had worst performanse. Any idea about cause of this.
Thx


#2

Unfortunately there is no way for us to explain why the 4k block size has such poor results. Have you tried running the 4k test again to verify the obtained results?


#3

Yes, same thing again. I will try to use spotlight now to see if I can find some bottleneck. The byte transfer rate was also vary low on 4K. It is almost as there is to much locking between users when I use 4K so user contention creates problem, but I am still not sure this is a problem. Thx anyway


#4

After runing analisys I found that the problem of bad TPCE performance at 4K oracle block size caused by slow single physical block read time. But I still can’t get it why is physical block read time this slow on 4K oracle block size, and not at 8K or 2K. In an attachmat i post more detail report. Any idea?
P.S NEWTS is tablespace which is used for TPCE test

Message was edited by: sirijus
IO Tablespace (orcl) - Tablespaces.csv (443 Bytes)


#5

After runing analisys I found that the problem of bad TPCE performance at 4K oracle block size caused by slow single physical block read time. But I still can’t get it why is physical block read time this slow on 4K oracle block size, and not at 8K or 2K. In an attachmat i post more detail report. Any idea?
P.S NEWTS is tablespace which is used for TPCE test

Message was edited by: sirijus
Spotlight Summary Report.pdf (73.2 KB)