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We're working on a more comprehensive explanation of why EdgeDB isn't an ORM. Does EdgeDB do "object-relational mapping" under the hood — absolutely. The reason

We're working on a more comprehensive explanation of why EdgeDB isn't an ORM. Does EdgeDB do "object-relational mapping" under the hood — absolutely. The reason we try to distance ourselves from the category of ORMs is that the term "ORM" comes with a big bag of preconceptions that don't apply here. EdgeDB has: - Full schema model with indexing, constraints, defaults, computed properties, stored procedures - A query language that replaces SQL. If there's something you can do in SQL that isn't possible in EdgeQL, it's a bug. - The query language is backed by a full type system, grammar, set of functions and operators, etc. - A set of drivers for different languages that implement our binary protocol. By any definition, EdgeDB is a database. It's a new abstraction built on a lower-level abstraction: Postgres's query engine. Both abstractions indubitably fit any reasonable definition of "database". Basically: just because there's a declarative object-oriented schema doesn't mean this "is just an ORM" (unless your definition is quite pedantic).

henryfjordan 5y ago
How exactly is EdgeDB run? Is it a separate process from Postgres, or some kind of plugin? Can I run it over an existing Postgres instance? If I build a DB Schema in EdgeDB, can I interact with the underlying Postgres instance using regular SQL?
- RedCrowbar 5y ago
  It runs as a separate (stateless) process between the client and the PostgreSQL server. There was a talk about the details of the architecture on the live stream today: https://youtu.be/WRZ3o-NsU_4?t=5294 https://youtu.be/WRZ3o-NsU_4?t=5294
  - nicoburns 5y ago
    This sounds very similar to Hasura, which compiles graphQL down to SQL. Have you considered adding the subscription feature like they have?
    - RedCrowbar 5y ago
      It's something we want to do at some point, but unlike Hasura, which operates on GraphQL which is conceptually much simpler and limited, EdgeQL would be much harder to fit onto a "pipelined polling" model that Hasura utilizes to implement subs.
  - spqrtan117 5y ago
    So, there is, basically, no way to work with Postgres directly, as well as installing EdgeDB with the use of the existing Postgres installation and its data, right? Feels like a Postgres is a prisoner of the EdgeDB :)
    - dragonsh 5y ago
      If you look at the code they used to have —postgres-dsn URL, now they changed it to —backend-dsn. If you go beyond the marketing, edgedb is a postgres connection pool+orm combined together with a query language (its a huge work in itself and commendable given it takes away many dependencies and provide a consistent developer experience). It’s leveraging postgresql server which is the true database providing ACID compliance. Edgedb is more akin to hasura than to a database in traditional sense.
      - spqrtan117 5y ago
        Hi there! Yes, I do understand and that the EdgeDB is "a postgres connection pool+orm combined together" and the work guys did is incredible. And I do beleive it will find its niche. But for me, personaly, the idea of "postgres is now a black box for you, don't even try to go deeper into it" stops me from digging into EdgeDB right away (the tooling is amazing! migrations!) and even trying it in our production for our enterprize clients. Probably, with time, when edgeql can fully replace sql and plpgsql, we could say that EdgeDB is ready for everything. BTW, @RedCrowbar, how can I call a udf or procedure (written in sql/plpgsql) from edgeql? I didn't find it in the docs.
        RedCrowbar 5y ago
        There is no way to call UDF SQL (or PL/pgSQL) functions from EdgeDB, because there is no way to _define_ or manage them. The only place that is allowed to do this is the standard library (and, in the near future, extensions). We realize that the database must be extensible and flexible, so non-EdgeQL UDF will become a reality (and if things work out the way we hope they will, they'll be amazing and far beyond what you can do with plpgsql).
heleninboodler 5y ago
Re "just an ORM", it seems like the word "mapper" is the hint that it isn't, since there's no "mapping" from the object-oriented view to the big-pile-of-scalars in a traditional relational db.

henryfjordan 5y ago

How exactly is EdgeDB run? Is it a separate process from Postgres, or some kind of plugin? Can I run it over an existing Postgres instance? If I build a DB Schema in EdgeDB, can I interact with the underlying Postgres instance using regular SQL?

RedCrowbar 5y ago
It runs as a separate (stateless) process between the client and the PostgreSQL server. There was a talk about the details of the architecture on the live stream today: https://youtu.be/WRZ3o-NsU_4?t=5294 https://youtu.be/WRZ3o-NsU_4?t=5294
- nicoburns 5y ago
  This sounds very similar to Hasura, which compiles graphQL down to SQL. Have you considered adding the subscription feature like they have?
  - RedCrowbar 5y ago
    It's something we want to do at some point, but unlike Hasura, which operates on GraphQL which is conceptually much simpler and limited, EdgeQL would be much harder to fit onto a "pipelined polling" model that Hasura utilizes to implement subs.
- spqrtan117 5y ago
  So, there is, basically, no way to work with Postgres directly, as well as installing EdgeDB with the use of the existing Postgres installation and its data, right? Feels like a Postgres is a prisoner of the EdgeDB :)
  - dragonsh 5y ago
    If you look at the code they used to have —postgres-dsn URL, now they changed it to —backend-dsn. If you go beyond the marketing, edgedb is a postgres connection pool+orm combined together with a query language (its a huge work in itself and commendable given it takes away many dependencies and provide a consistent developer experience). It’s leveraging postgresql server which is the true database providing ACID compliance. Edgedb is more akin to hasura than to a database in traditional sense.
    - spqrtan117 5y ago
      Hi there! Yes, I do understand and that the EdgeDB is "a postgres connection pool+orm combined together" and the work guys did is incredible. And I do beleive it will find its niche. But for me, personaly, the idea of "postgres is now a black box for you, don't even try to go deeper into it" stops me from digging into EdgeDB right away (the tooling is amazing! migrations!) and even trying it in our production for our enterprize clients. Probably, with time, when edgeql can fully replace sql and plpgsql, we could say that EdgeDB is ready for everything. BTW, @RedCrowbar, how can I call a udf or procedure (written in sql/plpgsql) from edgeql? I didn't find it in the docs.
      - RedCrowbar 5y ago
        There is no way to call UDF SQL (or PL/pgSQL) functions from EdgeDB, because there is no way to _define_ or manage them. The only place that is allowed to do this is the standard library (and, in the near future, extensions). We realize that the database must be extensible and flexible, so non-EdgeQL UDF will become a reality (and if things work out the way we hope they will, they'll be amazing and far beyond what you can do with plpgsql).

heleninboodler 5y ago

Re "just an ORM", it seems like the word "mapper" is the hint that it isn't, since there's no "mapping" from the object-oriented view to the big-pile-of-scalars in a traditional relational db.