Querydsl VS Presto

There is a bit of tooling needed but is already around. For Java for example I had very good experience with a combination of flyway [1] for migrations, testcontainers [2] for making integration tests as easy as unit tests and querydsl [3] for a query and mapping layer.

[1] https://github.com/flyway/flyway

[2] https://java.testcontainers.org/modules/databases/postgres/

[3] https://github.com/querydsl/querydsl

http://querydsl.com/ also seems similar

As for JPA: I cannot miss the QueryDSL library for building typesafe queries. Another interesting alternative is Jinq, that provides a java stream api to query entities.

> all I really want is a nice API for building queries (that actually supports all underlying database features) and automatic mapping of the results to whatever objects/structs and primitives the language supports.

For Java based solutions, check out https://www.jooq.org/ or http://querydsl.com/

QueryDsl -- http://querydsl.com

We have some of this functionality in Presto (https://github.com/prestodb/presto), but it takes fair bit of work to implement it for all the different backends.

Note that glibc has a similar problem in multithreaded contexts. It strands unused memory in thread-local pools, which grows your memory usage over time like a memory leak. We got lower memory usage that didn't grow over time by switching to jemalloc.

Example of this: https://github.com/prestodb/presto/issues/8993

I look at the grammar. Here is preto's grammar which is mostly similar to other sql engines: https://github.com/prestodb/presto/blob/master/presto-parser/src/main/antlr4/com/facebook/presto/sql/parser/SqlBase.g4

export MVNW_VERBOSE=true git clone https://github.com/prestodb/presto.git cd presto bash ./mvnw clean install

more specifically, recently started learning about Presto [paper], and have been diving deeper into [source] code.

Presto