I came across UnQLite the other day in Stack Overflow and it has me intrigued for some software I'm working on. However, very few tests have been published on how well it performs. There are plenty of questions and public data available that help on SQLite and others but nothing on UnQLite. (I'm looking at serverless databases, hence my mention of SQLite. I understand that SQLite is relational whereas UnQLite is KVP and the two are not forked from the same parent projects)

I'd like to know:

  • What UnQLite seems to achieve in read/write speeds
  • What types of reads and writes (sequential, synchronous, large data, batch, random, etc.) it does well at compared to some other databases
  • Where bottlenecking seems to occur
  • How large the database tends to get (disk size or rows) before the time it takes to find and extract data begins to see a significant increase (i.e. slows down)
  • If at all possible, what disk format(s) (ext3/4, NTFS, exFAT, HFS+) cause problems for the database
  • Any recommended ways of optimizing performance with it

Thank you.

1 Answer 1


I have found some information and pointers here. Extracts from that thread:

...retrieved records from a given collection a parsed only once (FastJSON) and cached in-memory for fast retrieval. The cache is a O(1) hashtable so performance shouldn't be a problem.

...only the first retrieval is a little bit slower than the others since it involve a disk access (In case you are working with an on-disk DB) and a preprocessing phase (FastJSON decoding) while later fetches are in-memory operations only with no decoding overhead.

My Observations about document storage in UnQlite :

In memory: Store faster, search slower ;But both slower than SQLite!
In File: Store slower, search faster

e.g:- For same data, In UnQLite:

In mem: store: 901.9 ms, search: 2586 ms
In Local disk: store: 15223.3 ms , search: 114.2 ms

SQLite: In mem: Store 9507 ms , Search : 105 ms

Honestly, I haven't benchmarked SQLite indexes with UnQLite doc store. But, keep in mind that UnQLite is shipped with a disk KV storage engine that support nearly O(1) record retrieval.

The information given lacks specifics and context - nothing how the tests were conducted. Yet I believe it's enough to construct myself a vague opinion.

To me it seem that UnQLite has faster write but slower read performance, in relation to SQLite. It is probably a general trend when comparing SQL with NoSQL database systems.


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