OK, calling it a benchmark is a bit of an overstatement. It's taking two different database libraries for a quick spin, and seeing how fast they can write a bunch of integers to disk. A second benchmark checks how fast we can read them.
In this mini-test, I'm running leveldb against a new embedded database library, let's call it system_x. The purpose is really just so that I can remember some rough numbers regarding these useful database libraries.
I used the time command to gather results, which shows real, user and sys time spent.
Take with a grain of salt: It's seems that system_x (w. index) can perform random point reads 3.75 times faster than leveldb, but spends 4 times longer writing the data (sequentially).
Result
Here I present the timings data I measured for writes and reads. Something that I would like to measure, but did not do, is how long it takes to scan all the data. Both database libraries support iterating over all the records.
1 million sequential writes
Writing 1 million key-value pairs (two integers as strings) sequentially.
leveldb (indexed):
real 0m8.329s user 0m8.264s sys 0m0.223s |
system_x (not indexed):
real 0m3.456s user 0m2.920s sys 0m0.105s |
system_x (indexed):
real 0m34.464s user 0m33.766s sys 0m0.156s |
10K single reads
Reading every 100th key-value pair written during sequential write phase (above).
leveldb (indexed)
real 0m0.929s user 0m0.267s sys 0m0.043s |
system_x (not indexed)
real 0m15.410s user 0m15.262s sys 0m0.078s |
system_x (indexed)
real 0m0.099s user 0m0.074s sys 0m0.023s |
Conclusion
- system_x w/o index: Faster sequential write, paid for by slower random reads (not surprising)
- system_x w. index: Faster random reads, paid for by slower sequential writes (perhaps the real take-away).