Oracle Transparent Data Encryption (TDE) is easy to benchmark for performance, using the techniques from the book "Database Benchmarking".

Oracle encryption can affect the performance of your database in several ways.  With TDE deployed we see a push-pull effect.  Overall, the benchmark slows that I/O writes being reduced while CPU increases, resulting in slowing SQL throughput:

• Slower transaction throughput - As we expect, Oracle transactions run faster without the encryption/decryption processing overhead.  This encryption benchmark shows significantly slower throughput when deploying TDE, almost 20% (81 transactions/second with TDE, 121 transactions/second with TDE).

• Less Disk Writes - Since transparent data encryption compresses the data, the benchmark with TDE required less disk writes.

• More CPU required - As we would expert, TDE required CPU cycles for the encrypt/decrypt operations, and in this benchmark test we see User CPU rise from 46 to 80 when using TDE data encryption.

Benchmark test results using TDE encryption

Gokul performed this benchmark test of Oracle encryption in 11g HP/UX, using swingbench to generate load data, and measuring I/O and system resources both within Oracle and externally using the HP/UX sar utility. 

Here are the test results from his encryption benchmark test.  Note that Gokul fired off 85 concurrent sessions with 30,000 transactions, a statistically valid test size. Statistically significant test result differences are highlighted for easy reading:

		Oracle TDE	Oracle Plain
File System		VxFS	VxFS
Cache Hit %		77.57	69.47
No. of Threads		85	85
Execution Time (Seconds)		372	249
Transactions Per Second		81	121
Total transactions		30,000	30,000
CPU u/s/i %		80/5/15	46/10/44
Data Datafile	Read	23,520	24,030
	Write	27,720	51,300
	Blocks	853,860	1,402,110
Index Datafile	Read	27,720	34,020
	Write	64,260	77,220
	Blocks	1,743,840	1,980,720
Redo Log	Read	19,320	18,090
	Write	37,800	35,370
	Blocks	600,600	591,300
Others (System + Sysaux + Undo+Users+Control + Temp)	Read	420	2,970
	Write	15,540	35,910
	Blocks	275,940	763,560
SAR Total	Read	70,980	79,110
	Write	145,320	199,800
	Blocks	34,74,240	4,737,690
Oracle IO	Read	4,695,039	4,803,706
	Write	107,460	171,687
Data Manipulation Statements      (in numbers)	Select	104,001	103,711
	Insert	56,867	56,420
	Update	35,487	34,614
	Commit	43,519	43,419
	Rollback	171	183
Total Statements		24,0045	238,347

See our related notes on Oracle transparent data encryption (TDE):

• Introduction to TDE

• Understanding transparent tablespace encryption

• Oracle 11g Data Compression Tips for the Database Administrator

 

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