integresql VS hash-db

For the case of PostgreSQL I've found IntegreSQL and its Javascript client really helpful because it can create a copy of the database per test case, which it helps to write integration tests with real DB calls.

Mocking has some advantages, but so does using a real database, at work we use https://github.com/allaboutapps/integresql and I quite like the approach that integresql has, since it makes possible to have a fresh database with your dummy data for every test without impacting the execution speed (compared to dropping an re-creating the database).

Happy to hear that! When it comes to testing services that depend on PostgreSQL, this is still my preferred solution.

https://github.com/allaboutapps/integresql

disclaimer: author

I haven't had a change to try it yet, but IntegreSQL[0] looks like this on steroids. It allows you to create a template (runs migrations and seed dates), and then uses Postgres's built in cloning functionality to maintain a pool of fresh databases. They claim 500ms to clone a database without the pool, and that the pool pretty much hides the latency entirely.

[0]: https://github.com/allaboutapps/integresql

https://github.com/samsquire/hash-db

I need to combine the ideas in each of these projects into a cohesive solution.

I did some work on trying to implement the YATA algorithm, poorly.

From an SQL database implementation perspective, in my toy Python barebones SQL database that barely supports inner joins (https://github.com/samsquire/hash-db) I tested by testing on postgresql and seeing if my query with two joins produces the same results.

I ought to produce unit tests that prove that tuples from each join operation produces the correct dataset.

For a user perspective, I guess you could write some tooling that loads example data into a database and does an incremental join with each part of the join statement added.

I wrote a toy dynamodb, SQL, Cypher graph and document storage database engine in Python for the learning.

https://github.com/samsquire/hash-db

I am interested in database internals. Btrees come up with regard to designing database systems that are efficient to query on disk. Postgres uses them for its indexes. Radix trees are memory efficient tries which are useful for answering prefix queries. They're also called prefix trees. I use them to get a list of prefixes of a string. Useful for simple intellisense style forms or dynamodb style querying. I've also been studying LSM trees which are used in Leveldb and RocksDB.

I experiment with database technology in my experimental project hash-db https://github.com/samsquire/hash-db The code should be readable.

I need to change my search tree to be self balancing currently it grows to the left or right without balancing. I think I need to use tree rotation depending on which branch has the highest height.