### Description
This PR changes the internal representation of a parsed remote schema. We were still using a list of type definitions, meaning every time we were doing a type lookup we had to iterate through a linked list! 🙀 It was very noticeable on large schemas, that need to do a lot of lookups. This PR consequently changes the internal representation to a HashMap. Building the OneGraph schema on my machine now takes **23 seconds**, compared to **367 seconds** before this patch.
Some important points:
- ~~this PR removes a check for type duplication in remote schemas; it's unclear to me whether that's something we need to add back or not~~ (no longer true)
- this PR makes it obvious that we do not distinguish between "this remote schema is missing type X" and "this remote schema expects type X to be an object, but it's a scalar"; this PR doesn't change anything about it, but adds a comment where we could surface that error (see [2991](https://github.com/hasura/graphql-engine-mono/issues/2991))
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/2963
GitOrigin-RevId: f5c96ad40f4e0afcf8cef635b4d64178111f98d3
This commit applies ormolu to the whole Haskell code base by running `make format`.
For in-flight branches, simply merging changes from `main` will result in merge conflicts.
To avoid this, update your branch using the following instructions. Replace `<format-commit>`
by the hash of *this* commit.
$ git checkout my-feature-branch
$ git merge <format-commit>^ # and resolve conflicts normally
$ make format
$ git commit -a -m "reformat with ormolu"
$ git merge -s ours post-ormolu
https://github.com/hasura/graphql-engine-mono/pull/2404
GitOrigin-RevId: 75049f5c12f430c615eafb4c6b8e83e371e01c8e
Remote relationships are now supported on SQL Server and BigQuery. The major change though is the re-architecture of remote join execution logic. Prior to this PR, each backend is responsible for processing the remote relationships that are part of their AST.
This is not ideal as there is nothing specific about a remote join's execution that ties it to a backend. The only backend specific part is whether or not the specification of the remote relationship is valid (i.e, we'll need to validate whether the scalars are compatible).
The approach now changes to this:
1. Before delegating the AST to the backend, we traverse the AST, collect all the remote joins while modifying the AST to add necessary join fields where needed.
1. Once the remote joins are collected from the AST, the database call is made to fetch the response. The necessary data for the remote join(s) is collected from the database's response and one or more remote schema calls are constructed as necessary.
1. The remote schema calls are then executed and the data from the database and from the remote schemas is joined to produce the final response.
### Known issues
1. Ideally the traversal of the IR to collect remote joins should return an AST which does not include remote join fields. This operation can be type safe but isn't taken up as part of the PR.
1. There is a lot of code duplication between `Transport/HTTP.hs` and `Transport/Websocket.hs` which needs to be fixed ASAP. This too hasn't been taken up by this PR.
1. The type which represents the execution plan is only modified to handle our current remote joins and as such it will have to be changed to accommodate general remote joins.
1. Use of lenses would have reduced the boilerplate code to collect remote joins from the base AST.
1. The current remote join logic assumes that the join columns of a remote relationship appear with their names in the database response. This however is incorrect as they could be aliased. This can be taken up by anyone, I've left a comment in the code.
### Notes to the reviewers
I think it is best reviewed commit by commit.
1. The first one is very straight forward.
1. The second one refactors the remote join execution logic but other than moving things around, it doesn't change the user facing functionality. This moves Postgres specific parts to `Backends/Postgres` module from `Execute`. Some IR related code to `Hasura.RQL.IR` module. Simplifies various type class function signatures as a backend doesn't have to handle remote joins anymore
1. The third one fixes partial case matches that for some weird reason weren't shown as warnings before this refactor
1. The fourth one generalizes the validation logic of remote relationships and implements `scalarTypeGraphQLName` function on SQL Server and BigQuery which is used by the validation logic. This enables remote relationships on BigQuery and SQL Server.
https://github.com/hasura/graphql-engine-mono/pull/1497
GitOrigin-RevId: 77dd8eed326602b16e9a8496f52f46d22b795598
This reverts the remote schema type customisation and namespacing feature temporarily as we test for certain conditions.
GitOrigin-RevId: f8ee97233da4597f703970c3998664c03582d8e7
