Dell Compellent Series 40 - Manual (Page 12)

Cost and Performance benefits of Dell™ Compellent™ Automated Tiered Storage for Oracle® OLAP
Workloads
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Test results and analysis
As explained in the test methodology, we used the Quest benchmark TPC-H tool with 500 GB of data
loaded. After loading the data, the total size of all database volumes was around 950GB including FRA.
Initially, we started testing the OLAP database on a single tier (SAS15K RPM) with Data Progression,
Data Instant Replay, and Fast Track disabled. This was to get baseline results like traditional storage
without any Dell Compellent auto-tiering features. Then we conducted Quest benchmark TPC-H tests
on the database by enabling each of those tiering features one-by-one as mentioned above and
gathered performance numbers in terms of average query response time. For each test scenario, we
captured the overall disk space consumed by all database volumes in the Compellent storage.
Figure 7 shows the response time comparison between baseline configurations without any Compellent
auto tiering features enabled (to simulate a traditional storage system) and with Fast track enabled.
Average response time: Baseline vs. Fast Track enabled Figure 7.
The above test result reveals that the baseline test carried out without Fast Track on all volumes
residing on the SAS 15K RPM drives took an average response time of 448 minutes whereas on the same
storage configuration when the Compellent Fast Track feature is enabled, after couple of test
iterations, we observed that the average response time was reduced to 345 min. This result is because
Dell Compellent Fast Track moves frequently accessed data blocks to the outer sectors of the drives. In
the above test, there was clearly a 23 percent improvement in the performance by enabling Dell
Compellent Fast Track. In addition, we observed that Dell Compellent Fast Track does not bring a cost
advantage by means of disk space savings.
Figure 8 shows the response time comparison between baseline configurations without any Compellent
auto-tiering features enabled (to simulate a traditional storage system) and Dell Compellent Fast Track
and Replay enabled.
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