Commit Graph

969 Commits

Author SHA1 Message Date
Robert
11a454c2d6 server, pro: actually reformat the code-base using ormolu
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
2021-09-23 22:57:37 +00:00
Naveen Naidu
3d95c67748 server/query-tags: implement new metadata specification and API
https://github.com/hasura/graphql-engine-mono/pull/2203

GitOrigin-RevId: 6169fcce0c6dccaec055bf8e723e9aa7c19a7f0c
2021-09-23 12:38:56 +00:00
Rakesh Emmadi
cfd76a36bf server/mssql: improve mssql transactions
>

### Description
>
Few improvements to mssql transactions.

### Changelog

- [ ] `CHANGELOG.md` is updated with user-facing content relevant to this PR. If no changelog is required, then add the `no-changelog-required` label.

### Affected components

- [x] Server
- [ ] Console
- [ ] CLI
- [ ] Docs
- [ ] Community Content
- [ ] Build System
- [ ] Tests
- [ ] Other (list it)

https://github.com/hasura/graphql-engine-mono/pull/2324

GitOrigin-RevId: 808947188f5f3d196c7dfc4ebfa661629db5f8f7
2021-09-23 09:10:28 +00:00
Robert
bdacf1bd23 server: remove ApplicativeDo from default extensions
I spent half the day reducing a weird compile failure here https://github.com/hasura/graphql-engine-mono/pull/1593/files#r713102990 to this https://gitlab.haskell.org/ghc/ghc/-/issues/17768#note_378004. Seems ApplicativeDo makes a mess of non-applicative monadic do in some cases. Given our rather localized use of ApplicativeDo, seemed a good idea to remove it from the list of default extensions.

It appears that ApplicativeDo also buries some unused return value warnings, so this PR also silences those. We should check that none of those warnings were warranted though.

https://github.com/hasura/graphql-engine-mono/pull/2413

GitOrigin-RevId: 1874c1a82230431849265755b1407beebc947041
2021-09-22 15:35:54 +00:00
jkachmar
112d206fa6 Adds Remote Source Join Execution
https://github.com/hasura/graphql-engine-mono/pull/2038

Co-authored-by: Phil Freeman <630306+paf31@users.noreply.github.com>
GitOrigin-RevId: 0843bd0610822469f727d768810694b748fec790
2021-09-22 10:44:01 +00:00
Evie Ciobanu
1843ee7b0b [server] fix LIMIT optimization not respecting ORDER BY
https://github.com/hasura/graphql-engine-mono/pull/2239

Co-authored-by: Gil Mizrahi <8547573+soupi@users.noreply.github.com>
Co-authored-by: Rakesh Emmadi <12475069+rakeshkky@users.noreply.github.com>
GitOrigin-RevId: fabc825239950b11d673cfd33e8075a01409bcf6
2021-09-21 10:40:24 +00:00
Antoine Leblanc
21254256a1 Improve error messages of Metadata API.
### Description

This PR improves error messages in our metadata API by displaying a message with the name of the failing command and a link to our documentation. Furthermore, it harmonizes our internal uses of `withObject`, to respect the convention of using the Haskell type name, now that the Aeson error message is displayed as an "internal error message".

https://github.com/hasura/graphql-engine-mono/pull/1905

GitOrigin-RevId: e4064ba3290306437aa7e45faa316c60e51bc6b6
2021-09-20 19:50:22 +00:00
pranshi06
e77b79ae02 [server] Add GraphQL query in the payload for Synchronous Actions
https://github.com/hasura/graphql-engine-mono/pull/2224

GitOrigin-RevId: 9eb1ab612f1a6cc8fe8490272be3d5a997b5b097
2021-09-20 18:20:33 +00:00
Karthikeyan Chinnakonda
ccf97ab6b0 server: improve event trigger logging
https://github.com/hasura/graphql-engine-mono/pull/2286

GitOrigin-RevId: b3232a08dd7ec2aa0c9e7a2fada0e05e34a1897b
2021-09-20 14:32:31 +00:00
Aniket Deshpande
d358d06e68 MSSQL: custom-check based permissions _exists uses wrong table graphql-engine#7429
https://github.com/hasura/graphql-engine-mono/pull/2317

GitOrigin-RevId: 2ea6c69811d06676c6ea7cf5371c28f021037d72
2021-09-20 10:27:14 +00:00
Karthikeyan Chinnakonda
5f79b5f102 server: generalize the event triggers codepath for all backends
https://github.com/hasura/graphql-engine-mono/pull/2189

Co-authored-by: hasura-bot <30118761+hasura-bot@users.noreply.github.com>
Co-authored-by: Martin Mark <74692114+martin-hasura@users.noreply.github.com>
Co-authored-by: Vishnu Bharathi <4211715+scriptnull@users.noreply.github.com>
Co-authored-by: Sameer Kolhar <6604943+kolharsam@users.noreply.github.com>
Co-authored-by: Antoine Leblanc <1618949+nicuveo@users.noreply.github.com>
Co-authored-by: Matt Hardman <28978422+mattshardman@users.noreply.github.com>
Co-authored-by: Vijay Prasanna <11921040+vijayprasanna13@users.noreply.github.com>
Co-authored-by: Divi <32202683+imperfect-fourth@users.noreply.github.com>
GitOrigin-RevId: 97c71571656c6e0c57d06f2d38193833180901c0
2021-09-20 07:35:49 +00:00
Rakesh Emmadi
9ca0bc1e5c server: remove identity notion from table columns
>

### Description
>
While adding [insert mutation schema parser for MSSQL backend](https://github.com/hasura/graphql-engine-mono/pull/2141) I also included [identity](https://en.wikipedia.org/wiki/Identity_column) notion to table columns across all backends. In MSSQL we cannot insert any value (even `DEFAULT` expression) into Identity columns. This behavior of identity columns is not same in Postgres as we can insert values. This PR drops the notion of identity in the column info. The context of identity columns for MSSQL is carried in `ExtraTableMetadata` type.

### Changelog

- [x] `CHANGELOG.md` is updated with user-facing content relevant to this PR. If no changelog is required, then add the `no-changelog-required` label.

### Affected components

- [x] Server
- [ ] Console
- [ ] CLI
- [ ] Docs
- [ ] Community Content
- [ ] Build System
- [x] Tests
- [ ] Other (list it)

### Related Issues
->
Fix https://github.com/hasura/graphql-engine/issues/7557

https://github.com/hasura/graphql-engine-mono/pull/2378

GitOrigin-RevId: c18b5708e2e6107423a0a95a7fc2e9721e8a21a1
2021-09-17 09:03:06 +00:00
Swann Moreau
8bfcd9a55c server: add "extensions" field to action webhook error schema
https://github.com/hasura/graphql-engine-mono/pull/1698

GitOrigin-RevId: c3b6f1048b6702a53ebe6c49f23dedc0f1d88090
2021-09-17 07:44:37 +00:00
Robert
d900a65399 server: Reduce and localize CPP usage
Some of our use of CPP causes trouble for ormolu, compare https://github.com/tweag/ormolu/issues/774.
Specifically, for understandable reasons, it can't deal well with `#ifdef` use that is not at the top-level.

This PR removes the problematic usage in ways that I hope are also a net non-loss regardless of helping
out ormolu (or other tooling).

- The default value for enabled APIs moves to the top level, next to the command line help, so
  they'll stay in sync more easily.
- All the CPP around using `assertNFHere` is moved to one module.

https://github.com/hasura/graphql-engine-mono/pull/2361

GitOrigin-RevId: ed6e039e6d8960322fd8d1312df762ad197c29b1
2021-09-16 18:52:37 +00:00
Karthikeyan Chinnakonda
169a49f2bb server: export metadata V2 should not export cron triggers with included_in_metadata: false
https://github.com/hasura/graphql-engine-mono/pull/2366

GitOrigin-RevId: 88c3a5a1f10ea1cf0e2192c69da5cc4147f70ae3
2021-09-16 15:08:45 +00:00
Antoine Leblanc
07fd7324c3 server: enable StrictData by default (fix hasura/graphql-engine#3941)
## Description

Almost all our data structures use strictness annotations, following [our styleguide's principle](https://github.com/hasura/graphql-engine/blob/master/server/STYLE.md#dealing-with-laziness) of "by default, use strict data types and lazy functions". The very few cases where we actually need laziness were already explicitly labelled as lazy with the `~` prefix operator.

This PR simply globally enables `StrictData`, allowing us to express records without `!()` on every field, but makes no attempt at cleaning existing code.

https://github.com/hasura/graphql-engine-mono/pull/1869

Co-authored-by: Philip Lykke Carlsen <358550+plcplc@users.noreply.github.com>
GitOrigin-RevId: e65c6e2f89413188da250122f64c2173615946ec
2021-09-16 12:23:15 +00:00
Solomon Bothwell
af5ff07614 Request Transformations
https://github.com/hasura/graphql-engine-mono/pull/1984

Co-authored-by: jkachmar <8461423+jkachmar@users.noreply.github.com>
GitOrigin-RevId: 1767d6bdde48c156fe171b5a9b7e44d7f2eb4869
2021-09-16 11:03:57 +00:00
David Overton
7c77c81cf9 return original schema in introspect_remote_schema
https://github.com/hasura/graphql-engine-mono/pull/2364

GitOrigin-RevId: 99698aa977bf8ff85e29d67a0956ff1509cd30be
2021-09-16 09:07:18 +00:00
Antoine Leblanc
e2ce1972f6 Prevent empty subscription roots (fix hasura/graphql-engine#6898)
### Description

We always build a subscription root, even when there was no possible fields. This breaks some third party clients, as the spec does not allow empty types in the schema. This PR fixes this by changing the `buildSubscriptionParser` helper to return a `Maybe` value, and harmonizes / cleans places where we build the subscription root.

https://github.com/hasura/graphql-engine-mono/pull/2357

GitOrigin-RevId: 1aeae25e321eee957e7645c436d17e69207309fd
2021-09-16 07:42:46 +00:00
Robert
fe035125f4 server: drop LazyTxT newtype
This is a follow-up to #1959.

Today, I spent a while in review figuring out that a harmless PR change didn't do anything,
because it was moving from a `runLazy...` to something without the `Lazy`. So let's get
that source of confusion removed.

This should be a bit easier to review commit by commit, since some of the functions had
confusing names. (E.g. there was a misnamed `Migrate.Internal.runTx` before.)

The change should be a no-op.

https://github.com/hasura/graphql-engine-mono/pull/2335

GitOrigin-RevId: 0f284c4c0f814482d7827e7732a6d49e7735b302
2021-09-15 20:46:45 +00:00
Antoine Leblanc
a5589c185b Fix nullability of nested objrel inserts (fix hasura/graphql-engine#7484)
### Description

During the PDV refactor that led to 2.0, we broke an undocumented and untested semantic of inserts: accepting _explicit_ null values in nested object inserts.

In short: in the schema, we often distinguish between _explicit_ null values `{id: 3, author: null}` and _implicit_ null values that correspond to the field being omitted `{id: 3}`. In this particular case, we forgot to accept explicit null values. Since the field is optional (meaning we accept implicit null values), it was nullable in the schema, like it was in pre-PDV times. But in practice we would reject explicit nulls.

This PR fixes this, and adds a test. Furthermore, it does a bit of a cleanup of the Mutation part of the schema, and more specifically of all insertion code.

https://github.com/hasura/graphql-engine-mono/pull/2341

GitOrigin-RevId: 895cfeecef7e8e49903a3fb37987707150446eb0
2021-09-15 13:11:48 +00:00
Karthikeyan Chinnakonda
982b5a3d15 server: log operation details for each query in a batch query execution
https://github.com/hasura/graphql-engine-mono/pull/2306

GitOrigin-RevId: 066a02fc57711b1faad447e6e448e3e004376c74
2021-09-15 08:30:32 +00:00
Philip Lykke Carlsen
5c54e33dcc Small revisions to documentation
This PR only contains minor changes to documentation that I have collected over some time, revising text as I was passing by.

https://github.com/hasura/graphql-engine-mono/pull/2346

Co-authored-by: Rikin Kachhia <54616969+rikinsk@users.noreply.github.com>
GitOrigin-RevId: f3329f3212b831f1f3c74a299734faff337b1017
2021-09-14 15:47:38 +00:00
Karthikeyan Chinnakonda
a268a3dc2f server: fix bug which allowed metadata to be inconsistent in the replace_metadata API call
https://github.com/hasura/graphql-engine-mono/pull/2288

GitOrigin-RevId: 93b181c957a5c38748c419a5146f0590605957ce
2021-09-14 12:03:06 +00:00
Sameer Kolhar
bafefac73d server: update create_scheduled_event API to respond with event_id
https://github.com/hasura/graphql-engine-mono/pull/2313

GitOrigin-RevId: a72880734074105d55bb387fdb5d1a9f5fac1d72
2021-09-13 18:01:55 +00:00
Karthikeyan Chinnakonda
3247c8bd71 server: generalize event triggers - incremental PR 2
https://github.com/hasura/graphql-engine-mono/pull/2270

GitOrigin-RevId: d7644b25d3ee57ffa630de15ae692c1bfa03b4f6
2021-09-09 11:55:11 +00:00
Abby Sassel
9ebc07ef4f belatedly address code review feedback
https://github.com/hasura/graphql-engine-mono/pull/2322

GitOrigin-RevId: 9b56d3335e8151d223d2aeaa7a3550806cb7b273
2021-09-09 10:38:46 +00:00
Abby Sassel
16b09f7d52 server/mssql: support transactions
https://github.com/hasura/graphql-engine-mono/pull/2268

GitOrigin-RevId: b1bc2812cd403688228b3ecf143aa36b3a6af707
2021-09-09 07:59:55 +00:00
Karthikeyan Chinnakonda
81df199169 server: remove the execute command from the graphql-engine
https://github.com/hasura/graphql-engine-mono/pull/2318

GitOrigin-RevId: a07b39469fa84a1ae3c913955872dcaade689c6e
2021-09-08 13:07:18 +00:00
Sameer Kolhar
f6af579619 server,docs,tests: add support for connection_parameters to pg_add_source API
https://github.com/hasura/graphql-engine-mono/pull/1690

GitOrigin-RevId: a7be66c9af3143b34133d197f7858ba22f442a41
2021-09-06 17:00:12 +00:00
Robert
565e816716 server: don't use Show to encode error codes
This moves the previous (illegal) `Show` instance for `Hasura.Base.Error.Code` to a `ToJSON`
instance, and uses that in the error `ToJSON` instances.

Addressing https://github.com/hasura/graphql-engine-mono/pull/2277#issuecomment-911557169.
This PR is against #2277.

It adds a replacement derived `Show` instance, which is used:
- in the derived `Show` instance for `QErr`
- in some unit tests

Mostly verified that we didn't otherwise rely on the hand-rolled `Show`
instance by compiling without it (and a faked `QErr` instance), and seeing
that the only compile failures were in tests. (Compare the individual commits.)

https://github.com/hasura/graphql-engine-mono/pull/2279

GitOrigin-RevId: 678fe241a14bd0c9aaf5b267efc510ad9d619dd7
2021-09-06 15:49:56 +00:00
Sameer Kolhar
3bd7b9049d server: don't propogate tracecontext and userinfo for GraphQL queries on PG backends
https://github.com/hasura/graphql-engine-mono/pull/2294

GitOrigin-RevId: c4be1c04a676154a233e75b31ff00b689443b933
2021-09-06 14:30:40 +00:00
Anon Ray
dc1ac69dac server: add parameterized query hash for websocket logs
https://github.com/hasura/graphql-engine-mono/pull/2061

Co-authored-by: Naveen Naidu <30195193+Naveenaidu@users.noreply.github.com>
GitOrigin-RevId: bf26b804d93b19ef7fc15c71fec80fb6d6632e64
2021-09-06 12:27:48 +00:00
Karthikeyan Chinnakonda
94f3ad041c server: generalize event triggers - incremental PR 1
https://github.com/hasura/graphql-engine-mono/pull/2269

GitOrigin-RevId: c4ea0cc41a1c66d418219cc1d41bf95656426733
2021-09-06 11:16:32 +00:00
Robert
f9dfb84c55 server: sort and prune error codes
This sorts the constructors in `Hasura.Base.Error.Code`, and removes unused ones.

https://github.com/hasura/graphql-engine-mono/pull/2277

GitOrigin-RevId: 2faf68edf70492c21a846d626951e65012a37e7c
2021-09-03 11:47:59 +00:00
Rakesh Emmadi
10e01a4669 server/mssql: refine aggregate field SQL generation code
>

### Description
>
Correctly alias the aggregate field projections in site instead of aliasing them later stage.

PS: I discovered this required change while [developing SQL generation for MSSQL inserts](https://github.com/hasura/graphql-engine-mono/pull/2248).

### Changelog

- [ ] `CHANGELOG.md` is updated with user-facing content relevant to this PR. If no changelog is required, then add the `no-changelog-required` label.

### Affected components

- [x] Server

https://github.com/hasura/graphql-engine-mono/pull/2271

GitOrigin-RevId: 0d90fd8d8c0541b18ca9cb1197e413f3454bb227
2021-09-02 23:01:15 +00:00
Sameer Kolhar
afbc30fec5 server: set tracecontext and userInfo for DML actions on PG sources
https://github.com/hasura/graphql-engine-mono/pull/2174

GitOrigin-RevId: e8cfb4e330938e7dfb7232e58d2c1fc07bf97896
2021-09-01 17:57:39 +00:00
Rakesh Emmadi
7ca48decfb server/mssql: integrate insert mutation schema parser for MSSQL backend
>

### Description
>
This PR is an incremental work towards [enabling insert mutations on MSSQL](https://github.com/hasura/graphql-engine-mono/pull/1974). In this PR, we generate insert mutation schema parser for MSSQL backend.

### Changelog

- [ ] `CHANGELOG.md` is updated with user-facing content relevant to this PR. If no changelog is required, then add the `no-changelog-required` label.

### Affected components

- [x] Server

https://github.com/hasura/graphql-engine-mono/pull/2141

GitOrigin-RevId: 8595008dece35f7fded9c52e134de8b97b64f53f
2021-08-31 13:35:49 +00:00
Swann Moreau
4887f70caa [server] revert #2078 "server/postgres: optimize SQL query generation with LIMITs"
Fixes https://github.com/hasura/graphql-engine/issues/7453, by reverting #2078 (commit 47eaccdbfb3499efd2c9f733f3312ad31c77916f).

https://hasurahq.slack.com/archives/CKFUG6RCH/p1629900718181700

https://github.com/hasura/graphql-engine-mono/pull/2204

GitOrigin-RevId: 53d5fee9c6008b26bc14213e5a16f6aba6d9c6b1
2021-08-30 11:54:53 +00:00
Auke Booij
fe8eabff19 server: fix the nullability of object relationships (fix hasura/graphql-engine#7201)
When adding object relationships, we set the nullability of the generated GraphQL field based on whether the database backend enforces that the referenced data always exists. For manual relationships (corresponding to `manual_configuration`), the database backend is unaware of any relationship between data, and hence such fields are always set to be nullable.

For relationships generated from foreign key constraints (corresponding to `foreign_key_constraint_on`), we distinguish between two cases:

1. The "forward" object relationship from a referencing table (i.e. which has the foreign key constraint) to a referenced table. This should be set to be non-nullable when all referencing columns are non-nullable. But in fact, it used to set it to be non-nullable if *any* referencing column is non-nullable, which is only correct in Postgres when `MATCH FULL` is set (a flag we don't consider). This fixes that by changing a boolean conjunction to a disjunction.
2. The "reverse" object relationship from a referenced table to a referencing table which has the foreign key constraint. This should always be set to be nullable. But in fact, it used to always be set to non-nullable, as was reported in hasura/graphql-engine#7201. This fixes that.

Moreover, we have moved the computation of the nullability from `Hasura.RQL.DDL.Relationship` to `Hasura.GraphQL.Schema.Select`: this nullability used to be passed through the `riIsNullable` field of `RelInfo`, but for array relationships this information is not actually used, and moreover the remaining fields of `RelInfo` are already enough to deduce the nullability.

This also adds regression tests for both (1) and (2) above.

https://github.com/hasura/graphql-engine-mono/pull/2159

GitOrigin-RevId: 617f12765614f49746d18d3368f41dfae2f3e6ca
2021-08-26 15:27:34 +00:00
Lyndon Maydwell
605499e6da [pro, server] Allow response when cache limits are hit
https://github.com/hasura/graphql-engine-mono/pull/2094

GitOrigin-RevId: f8b186a7cf830f61226e7ea82631a4a9e5f269bc
2021-08-25 01:53:45 +00:00
Robert
c9481d4599 server: remove align, These(..) from Prelude
This removes the module re-exports of [Data.Align](https://hackage.haskell.org/package/semialign-1.2/docs/Data-Align.html) and [Data.These](https://hackage.haskell.org/package/these-1.1.1.1/docs/Data-These.html) from `Hasura.Prelude`. The reasoning being that they're not used widely and reasonably obscure, and that being explicit about the imports makes for an easier to understand codebase.

(I spent longer than I'd have liked earlier today figuring out where `align` in multitenant came from.
The right one not showing up on the first hoogle page doesn't help. Yes, better tool use could have
avoided that, but still...)

Do feel free to shoot this down, I won't insist on the change.

https://github.com/hasura/graphql-engine-mono/pull/2194

GitOrigin-RevId: 10f887b74538b17623bee6d6451c5aba11573fbd
2021-08-24 17:42:13 +00:00
Sameer Kolhar
edeb8c98fd server: support for graphql-ws protocol
https://github.com/hasura/graphql-engine-mono/pull/1655

Co-authored-by: Rakesh Emmadi <12475069+rakeshkky@users.noreply.github.com>
Co-authored-by: Vijay Prasanna <11921040+vijayprasanna13@users.noreply.github.com>
Co-authored-by: hasura-bot <30118761+hasura-bot@users.noreply.github.com>
Co-authored-by: Brandon Simmons <210815+jberryman@users.noreply.github.com>
Co-authored-by: Varun Choudhary <68095256+Varun-Choudhary@users.noreply.github.com>
Co-authored-by: Divi <32202683+imperfect-fourth@users.noreply.github.com>
GitOrigin-RevId: 9db3902388fef06b94f9513255e2b5333bd23c3e
2021-08-24 16:26:12 +00:00
Auke Booij
99963a78c2 server: reduce memory usage during type collection by using a more concrete effect stack
Replaces one instance of `mtl`-style effects with `transformers`-style, as this results in a measurable reduction in memory usage. The change is kept completely within one module.

https://github.com/hasura/graphql-engine-mono/pull/1944

GitOrigin-RevId: 587b8e61725bb4a505404bbe741185759b7bceeb
2021-08-24 09:16:15 +00:00
Lyndon Maydwell
9a1c7d5ea0 server: Adding support for TLS allowlist by domain and service id (port)
https://github.com/hasura/graphql-engine-mono/pull/2153

Co-authored-by: Sameer Kolhar <6604943+kolharsam@users.noreply.github.com>
GitOrigin-RevId: 473a29af97236fc879ae178b0c2a6c31c1f12563
2021-08-24 07:37:25 +00:00
Robert
191e7a7ccf pro, server: simplify and unify limit resolution
This should be mostly a no-op change, with one exception:

When limits are not disabled, but neither node nor depth limit
is configured, we no longer count nodes/depth uselessly.

https://github.com/hasura/graphql-engine-mono/pull/2103

GitOrigin-RevId: 9943f89d6b969ca101a9a5601417c5b14a358a10
2021-08-23 19:27:11 +00:00
Auke Booij
67f2f49f33 server: remove stray comment
This re-removes a comment that was previously removed in
7bead93827 and re-added by
f49e13c890

https://github.com/hasura/graphql-engine-mono/pull/2186

GitOrigin-RevId: d16c19c8a0d5bed2a52b8033a1fe20cc6d6a2c92
2021-08-23 15:03:33 +00:00
David Overton
20f7a6e726 server: fix untrack_function for non-default source
https://github.com/hasura/graphql-engine-mono/pull/2152

GitOrigin-RevId: 339b365044443cec6a83e1a6b3ec06677dc51e1d
2021-08-19 10:28:49 +00:00
Rikin Kachhia
47f8bc9b42 server: update non-existent object error messages
https://github.com/hasura/graphql-engine-mono/pull/2098

GitOrigin-RevId: 61a10560a9df50afd80a6186e0d23b74874e3265
2021-08-18 10:52:28 +00:00
Rakesh Emmadi
fa152d842d server/postgres: optimize SQL query generation with LIMITs
>

### Description
>
This PR supersedes https://github.com/hasura/graphql-engine-mono/pull/1484. Apply `limit` to the table selection before joining relationship rows to improve query performance.

### Changelog

- [x] `CHANGELOG.md` is updated with user-facing content relevant to this PR. If no changelog is required, then add the `no-changelog-required` label.

### Affected components

- [x] Server

### Related Issues
->
Fix https://github.com/hasura/graphql-engine/issues/5745

### Solution and Design
>
Prior to this change, we apply `LIMIT` and `OFFSET` to the outer selection from sub-query which includes joins for relationships. Now, we move `LIMIT` and `OFFSET` (if present) to inner selection of base table. But, this isn't done always! If there are order by relationships' columns we apply at the outer selection. To know more, please refer to [source code note](https://github.com/hasura/graphql-engine-mono/pull/2078/files#diff-46d868ee45d3eaac667cebb34731f573c77d5c9c8097bb9ccf1115fc07f65bfdR652).

```graphql
query {
  article(limit: 2){
    id
    title
    content
    author{
      name
    }
  }
}
```
Before:
```sql
SELECT
  coalesce(json_agg("root"), '[]') AS "root"
FROM
  (
    SELECT
      row_to_json(
        (
          SELECT
            "_4_e"
          FROM
            (
              SELECT
                "_0_root.base"."id" AS "id",
                "_0_root.base"."title" AS "title",
                "_0_root.base"."content" AS "content",
                "_3_root.or.author"."author" AS "author"
            ) AS "_4_e"
        )
      ) AS "root"
    FROM
      (
        SELECT
          *
        FROM
          "public"."article"
        WHERE
          ('true')
      ) AS "_0_root.base"
      LEFT OUTER JOIN LATERAL (
        SELECT
          row_to_json(
            (
              SELECT
                "_2_e"
              FROM
                (
                  SELECT
                    "_1_root.or.author.base"."name" AS "name"
                ) AS "_2_e"
            )
          ) AS "author"
        FROM
          (
            SELECT
              *
            FROM
              "public"."author"
            WHERE
              (("_0_root.base"."author_id") = ("id"))
          ) AS "_1_root.or.author.base"
      ) AS "_3_root.or.author" ON ('true')
    LIMIT
      2
  ) AS "_5_root"
```
cost
```
Aggregate  (cost=0.73..0.74 rows=1 width=32)
  ->  Limit  (cost=0.15..0.71 rows=2 width=32)
        ->  Nested Loop Left Join  (cost=0.15..223.96 rows=810 width=32)
              ->  Seq Scan on article  (cost=0.00..18.10 rows=810 width=72)
              ->  Index Scan using author_pkey on author  (cost=0.15..0.24 rows=1 width=36)
                    Index Cond: (article.author_id = id)
                    SubPlan 1
                      ->  Result  (cost=0.00..0.01 rows=1 width=32)
              SubPlan 2
                ->  Result  (cost=0.00..0.01 rows=1 width=32)
```

After:
```sql
SELECT
  coalesce(json_agg("root"), '[]') AS "root"
FROM
  (
    SELECT
      row_to_json(
        (
          SELECT
            "_4_e"
          FROM
            (
              SELECT
                "_0_root.base"."id" AS "id",
                "_0_root.base"."title" AS "title",
                "_0_root.base"."content" AS "content",
                "_3_root.or.author"."author" AS "author"
            ) AS "_4_e"
        )
      ) AS "root"
    FROM
      (
        SELECT
          *
        FROM
          "public"."article"
        WHERE
          ('true')
        LIMIT
          2
      ) AS "_0_root.base"
      LEFT OUTER JOIN LATERAL (
        SELECT
          row_to_json(
            (
              SELECT
                "_2_e"
              FROM
                (
                  SELECT
                    "_1_root.or.author.base"."name" AS "name"
                ) AS "_2_e"
            )
          ) AS "author"
        FROM
          (
            SELECT
              *
            FROM
              "public"."author"
            WHERE
              (("_0_root.base"."author_id") = ("id"))
          ) AS "_1_root.or.author.base"
      ) AS "_3_root.or.author" ON ('true')
  ) AS "_5_root"
```
cost:
```
Aggregate  (cost=16.47..16.48 rows=1 width=32)
  ->  Nested Loop Left Join  (cost=0.15..16.44 rows=2 width=100)
        ->  Limit  (cost=0.00..0.04 rows=2 width=72)
              ->  Seq Scan on article  (cost=0.00..18.10 rows=810 width=72)
        ->  Index Scan using author_pkey on author  (cost=0.15..8.18 rows=1 width=36)
              Index Cond: (article.author_id = id)
              SubPlan 1
                ->  Result  (cost=0.00..0.01 rows=1 width=32)
  SubPlan 2
    ->  Result  (cost=0.00..0.01 rows=1 width=32)
```

https://github.com/hasura/graphql-engine-mono/pull/2078

Co-authored-by: Evie Ciobanu <1017953+eviefp@users.noreply.github.com>
GitOrigin-RevId: 47eaccdbfb3499efd2c9f733f3312ad31c77916f
2021-08-17 17:03:08 +00:00