graphql-engine/server/src-lib/Hasura/Backends/MSSQL/Instances/Schema.hs
Auke Booij 7bead93827 server: remove remnants of query plan caching (fix #1795)
Query plan caching was introduced by - I believe - hasura/graphql-engine#1934 in order to reduce the query response latency. During the development of PDV in hasura/graphql-engine#4111, it was found out that the new architecture (for which query plan caching wasn't implemented) performed comparably to the pre-PDV architecture with caching. Hence, it was decided to leave query plan caching until some day in the future when it was deemed necessary.

Well, we're in the future now, and there still isn't a convincing argument for query plan caching. So the time has come to remove some references to query plan caching from the codebase. For the most part, any code being removed would probably not be very well suited to the post-PDV architecture of query execution, so arguably not much is lost.

Apart from simplifying the code, this PR will contribute towards making the GraphQL schema generation more modular, testable, and easier to profile. I'd like to eventually work towards a situation in which it's easy to generate a GraphQL schema parser *in isolation*, without being connected to a database, and then parse a GraphQL query *in isolation*, without even listening any HTTP port. It is important that both of these operations can be examined in detail, and in isolation, since they are two major performance bottlenecks, as well as phases where many important upcoming features hook into.

Implementation

The following have been removed:
- The entirety of `server/src-lib/Hasura/GraphQL/Execute/Plan.hs`
- The core phases of query parsing and execution no longer have any references to query plan caching. Note that this is not to be confused with query *response* caching, which is not affected by this PR. This includes removal of the types:
- - `Opaque`, which is replaced by a tuple. Note that the old implementation was broken and did not adequately hide the constructors.
- - `QueryReusability` (and the `markNotReusable` method). Notably, the implementation of the `ParseT` monad now consists of two, rather than three, monad transformers.
- Cache-related tests (in `server/src-test/Hasura/CacheBoundedSpec.hs`) have been removed .
- References to query plan caching in the documentation.
- The `planCacheOptions` in the `TenantConfig` type class was removed. However, during parsing, unrecognized fields in the YAML config get ignored, so this does not cause a breaking change. (Confirmed manually, as well as in consultation with @sordina.)
- The metrics no longer send cache hit/miss messages.

There are a few places in which one can still find references to query plan caching:

- We still accept the `--query-plan-cache-size` command-line option for backwards compatibility. The `HASURA_QUERY_PLAN_CACHE_SIZE` environment variable is not read.

https://github.com/hasura/graphql-engine-mono/pull/1815

GitOrigin-RevId: 17d92b254ec093c62a7dfeec478658ede0813eb7
2021-07-27 11:52:43 +00:00

436 lines
16 KiB
Haskell

{-# OPTIONS_GHC -fno-warn-orphans #-}
module Hasura.Backends.MSSQL.Instances.Schema () where
import Hasura.Prelude
import qualified Data.HashMap.Strict as Map
import qualified Data.List.NonEmpty as NE
import qualified Database.ODBC.SQLServer as ODBC
import qualified Language.GraphQL.Draft.Syntax as G
import Data.Has
import Data.Text.Encoding (encodeUtf8)
import Data.Text.Extended
import qualified Hasura.Backends.MSSQL.Types as MSSQL
import qualified Hasura.GraphQL.Parser as P
import qualified Hasura.GraphQL.Schema.Build as GSB
import qualified Hasura.RQL.IR.Select as IR
import qualified Hasura.RQL.IR.Update as IR
import Hasura.Base.Error
import Hasura.GraphQL.Parser hiding (EnumValueInfo, field)
import Hasura.GraphQL.Parser.Internal.Parser hiding (field)
import Hasura.GraphQL.Schema.Backend
import Hasura.GraphQL.Schema.BoolExp
import Hasura.GraphQL.Schema.Common
import Hasura.GraphQL.Schema.Select
import Hasura.RQL.IR
import Hasura.RQL.Types
----------------------------------------------------------------
-- BackendSchema instance
instance BackendSchema 'MSSQL where
-- top level parsers
buildTableQueryFields = GSB.buildTableQueryFields
buildTableRelayQueryFields = msBuildTableRelayQueryFields
buildTableInsertMutationFields = msBuildTableInsertMutationFields
buildTableUpdateMutationFields = msBuildTableUpdateMutationFields
buildTableDeleteMutationFields = msBuildTableDeleteMutationFields
buildFunctionQueryFields = msBuildFunctionQueryFields
buildFunctionRelayQueryFields = msBuildFunctionRelayQueryFields
buildFunctionMutationFields = msBuildFunctionMutationFields
-- backend extensions
relayExtension = Nothing
nodesAggExtension = Just ()
-- table arguments
tableArguments = msTableArgs
-- individual components
columnParser = msColumnParser
jsonPathArg = msJsonPathArg
orderByOperators = msOrderByOperators
comparisonExps = msComparisonExps
updateOperators = msUpdateOperators
mkCountType = msMkCountType
aggregateOrderByCountType = MSSQL.IntegerType
computedField = msComputedField
node = msNode
-- SQL literals
columnDefaultValue = msColumnDefaultValue
----------------------------------------------------------------
-- Top level parsers
msBuildTableRelayQueryFields
:: MonadBuildSchema 'MSSQL r m n
=> SourceName
-> SourceConfig 'MSSQL
-> TableName 'MSSQL
-> TableInfo 'MSSQL
-> G.Name
-> NESeq (ColumnInfo 'MSSQL)
-> SelPermInfo 'MSSQL
-> m [FieldParser n (QueryRootField UnpreparedValue)]
msBuildTableRelayQueryFields _sourceName _sourceInfo _tableName _tableInfo _gqlName _pkeyColumns _selPerms =
pure []
msBuildTableInsertMutationFields
:: MonadBuildSchema 'MSSQL r m n
=> SourceName
-> SourceConfig 'MSSQL
-> TableName 'MSSQL
-> TableInfo 'MSSQL
-> G.Name
-> InsPermInfo 'MSSQL
-> Maybe (SelPermInfo 'MSSQL)
-> Maybe (UpdPermInfo 'MSSQL)
-> m [FieldParser n (MutationRootField UnpreparedValue)]
msBuildTableInsertMutationFields _sourceName _sourceInfo _tableName _tableInfo _gqlName _insPerms _selPerms _updPerms =
pure []
msBuildTableUpdateMutationFields
:: MonadBuildSchema 'MSSQL r m n
=> SourceName
-> SourceConfig 'MSSQL
-> TableName 'MSSQL
-> TableInfo 'MSSQL
-> G.Name
-> UpdPermInfo 'MSSQL
-> Maybe (SelPermInfo 'MSSQL)
-> m [FieldParser n (MutationRootField UnpreparedValue)]
msBuildTableUpdateMutationFields _sourceName _sourceInfo _tableName _tableInfo _gqlName _updPerns _selPerms =
pure []
msBuildTableDeleteMutationFields
:: MonadBuildSchema 'MSSQL r m n
=> SourceName
-> SourceConfig 'MSSQL
-> TableName 'MSSQL
-> TableInfo 'MSSQL
-> G.Name
-> DelPermInfo 'MSSQL
-> Maybe (SelPermInfo 'MSSQL)
-> m [FieldParser n (MutationRootField UnpreparedValue)]
msBuildTableDeleteMutationFields _sourceName _sourceInfo _tableName _tableInfo _gqlName _delPerns _selPerms =
pure []
msBuildFunctionQueryFields
:: MonadBuildSchema 'MSSQL r m n
=> SourceName
-> SourceConfig 'MSSQL
-> FunctionName 'MSSQL
-> FunctionInfo 'MSSQL
-> TableName 'MSSQL
-> SelPermInfo 'MSSQL
-> m [FieldParser n (QueryRootField UnpreparedValue)]
msBuildFunctionQueryFields _ _ _ _ _ _ =
pure []
msBuildFunctionRelayQueryFields
:: MonadBuildSchema 'MSSQL r m n
=> SourceName
-> SourceConfig 'MSSQL
-> FunctionName 'MSSQL
-> FunctionInfo 'MSSQL
-> TableName 'MSSQL
-> NESeq (ColumnInfo 'MSSQL)
-> SelPermInfo 'MSSQL
-> m [FieldParser n (QueryRootField UnpreparedValue)]
msBuildFunctionRelayQueryFields _sourceName _sourceInfo _functionName _functionInfo _tableName _pkeyColumns _selPerms =
pure []
msBuildFunctionMutationFields
:: MonadBuildSchema 'MSSQL r m n
=> SourceName
-> SourceConfig 'MSSQL
-> FunctionName 'MSSQL
-> FunctionInfo 'MSSQL
-> TableName 'MSSQL
-> SelPermInfo 'MSSQL
-> m [FieldParser n (MutationRootField UnpreparedValue)]
msBuildFunctionMutationFields _ _ _ _ _ _ =
pure []
----------------------------------------------------------------
-- Table arguments
msTableArgs
:: forall r m n
. MonadBuildSchema 'MSSQL r m n
=> SourceName
-> TableInfo 'MSSQL
-> SelPermInfo 'MSSQL
-> m (InputFieldsParser n (IR.SelectArgsG 'MSSQL (UnpreparedValue 'MSSQL)))
msTableArgs sourceName tableInfo selectPermissions = do
whereParser <- tableWhereArg sourceName tableInfo selectPermissions
orderByParser <- tableOrderByArg sourceName tableInfo selectPermissions
pure do
whereArg <- whereParser
orderByArg <- orderByParser
limitArg <- tableLimitArg
offsetArg <- tableOffsetArg
pure $ IR.SelectArgs
{ IR._saWhere = whereArg
, IR._saOrderBy = orderByArg
, IR._saLimit = limitArg
, IR._saOffset = offsetArg
-- not supported on MSSQL for now
, IR._saDistinct = Nothing
}
----------------------------------------------------------------
-- Individual components
msColumnParser
:: (MonadSchema n m, MonadError QErr m)
=> ColumnType 'MSSQL
-> G.Nullability
-> m (Parser 'Both n (ValueWithOrigin (ColumnValue 'MSSQL)))
msColumnParser columnType (G.Nullability isNullable) =
peelWithOrigin . fmap (ColumnValue columnType) <$> case columnType of
-- TODO: the mapping here is not consistent with mkMSSQLScalarTypeName. For
-- example, exposing all the float types as a GraphQL Float type is
-- incorrect, similarly exposing all the integer types as a GraphQL Int
ColumnScalar scalarType -> possiblyNullable scalarType <$> case scalarType of
-- bytestring
MSSQL.CharType -> pure $ ODBC.ByteStringValue . encodeUtf8 <$> P.string
MSSQL.VarcharType -> pure $ ODBC.ByteStringValue . encodeUtf8 <$> P.string
-- text
MSSQL.WcharType -> pure $ ODBC.TextValue <$> P.string
MSSQL.WvarcharType -> pure $ ODBC.TextValue <$> P.string
MSSQL.WtextType -> pure $ ODBC.TextValue <$> P.string
MSSQL.TextType -> pure $ ODBC.TextValue <$> P.string
-- integer
MSSQL.IntegerType -> pure $ ODBC.IntValue . fromIntegral <$> P.int
MSSQL.SmallintType -> pure $ ODBC.IntValue . fromIntegral <$> P.int
MSSQL.BigintType -> pure $ ODBC.IntValue . fromIntegral <$> P.int
MSSQL.TinyintType -> pure $ ODBC.IntValue . fromIntegral <$> P.int
-- float
MSSQL.NumericType -> pure $ ODBC.DoubleValue <$> P.float
MSSQL.DecimalType -> pure $ ODBC.DoubleValue <$> P.float
MSSQL.FloatType -> pure $ ODBC.DoubleValue <$> P.float
MSSQL.RealType -> pure $ ODBC.DoubleValue <$> P.float
-- boolean
MSSQL.BitType -> pure $ ODBC.BoolValue <$> P.boolean
_ -> do
name <- MSSQL.mkMSSQLScalarTypeName scalarType
let schemaType = P.NonNullable $ P.TNamed $ P.mkDefinition name Nothing P.TIScalar
pure $ Parser
{ pType = schemaType
, pParser =
valueToJSON (P.toGraphQLType schemaType) >=>
either (parseErrorWith ParseFailed . qeError) pure . (MSSQL.parseScalarValue scalarType)
}
ColumnEnumReference (EnumReference tableName enumValues) ->
case nonEmpty (Map.toList enumValues) of
Just enumValuesList -> do
tableGQLName <- tableGraphQLName @'MSSQL tableName `onLeft` throwError
let enumName = tableGQLName <> $$(G.litName "_enum")
pure $ possiblyNullable MSSQL.VarcharType $ P.enum enumName Nothing (mkEnumValue <$> enumValuesList)
Nothing -> throw400 ValidationFailed "empty enum values"
where
possiblyNullable _scalarType
| isNullable = fmap (fromMaybe ODBC.NullValue) . P.nullable
| otherwise = id
mkEnumValue :: (EnumValue, EnumValueInfo) -> (P.Definition P.EnumValueInfo, ScalarValue 'MSSQL)
mkEnumValue (EnumValue value, EnumValueInfo description) =
( P.mkDefinition value (G.Description <$> description) P.EnumValueInfo
, ODBC.TextValue $ G.unName value
)
msJsonPathArg
:: MonadParse n
=> ColumnType 'MSSQL
-> InputFieldsParser n (Maybe (IR.ColumnOp 'MSSQL))
msJsonPathArg _columnType = pure Nothing
msOrderByOperators
:: NonEmpty
( Definition P.EnumValueInfo
, (BasicOrderType 'MSSQL, NullsOrderType 'MSSQL)
)
msOrderByOperators = NE.fromList
[ ( define $$(G.litName "asc") "in ascending order, nulls first"
, (MSSQL.AscOrder, MSSQL.NullsFirst)
)
, ( define $$(G.litName "asc_nulls_first") "in ascending order, nulls first"
, (MSSQL.AscOrder, MSSQL.NullsFirst)
)
, ( define $$(G.litName "asc_nulls_last") "in ascending order, nulls last"
, (MSSQL.AscOrder, MSSQL.NullsLast)
)
, ( define $$(G.litName "desc") "in descending order, nulls last"
, (MSSQL.DescOrder, MSSQL.NullsLast)
)
, ( define $$(G.litName "desc_nulls_first") "in descending order, nulls first"
, (MSSQL.DescOrder, MSSQL.NullsFirst)
)
, ( define $$(G.litName "desc_nulls_last") "in descending order, nulls last"
, (MSSQL.DescOrder, MSSQL.NullsLast)
)
]
where
define name desc = P.mkDefinition name (Just desc) P.EnumValueInfo
msComparisonExps
:: forall m n r
. ( BackendSchema 'MSSQL
, MonadSchema n m
, MonadError QErr m
, MonadReader r m
, Has QueryContext r
)
=> ColumnType 'MSSQL
-> m (Parser 'Input n [ComparisonExp 'MSSQL])
msComparisonExps = P.memoize 'comparisonExps \columnType -> do
-- see Note [Columns in comparison expression are never nullable]
collapseIfNull <- asks $ qcDangerousBooleanCollapse . getter
-- parsers used for individual values
typedParser <- columnParser columnType (G.Nullability False)
nullableTextParser <- columnParser (ColumnScalar @'MSSQL MSSQL.VarcharType) (G.Nullability True)
textParser <- columnParser (ColumnScalar @'MSSQL MSSQL.VarcharType) (G.Nullability False)
let
columnListParser = fmap openValueOrigin <$> P.list typedParser
textListParser = fmap openValueOrigin <$> P.list textParser
-- field info
let
name = P.getName typedParser <> $$(G.litName "_MSSQL_comparison_exp")
desc = G.Description $ "Boolean expression to compare columns of type "
<> P.getName typedParser
<<> ". All fields are combined with logical 'AND'."
pure $ P.object name (Just desc) $ fmap catMaybes $ sequenceA $ concat
[
-- Common ops for all types
equalityOperators
collapseIfNull
(mkParameter <$> typedParser)
(mkListLiteral <$> columnListParser)
, comparisonOperators
collapseIfNull
(mkParameter <$> typedParser)
-- Ops for String like types
, guard (isScalarColumnWhere (`elem` MSSQL.stringTypes) columnType) *>
[ P.fieldOptional $$(G.litName "_like")
(Just "does the column match the given pattern")
(ALIKE . mkParameter <$> typedParser)
, P.fieldOptional $$(G.litName "_nlike")
(Just "does the column NOT match the given pattern")
(ANLIKE . mkParameter <$> typedParser)
]
-- Ops for Geometry/Geography types
, guard (isScalarColumnWhere (`elem` MSSQL.geoTypes) columnType) *>
[ P.fieldOptional $$(G.litName "_st_contains")
(Just "does the column contain the given value")
(ABackendSpecific . MSSQL.ASTContains . mkParameter <$> typedParser)
, P.fieldOptional $$(G.litName "_st_equals")
(Just "is the column equal to given value (directionality is ignored)")
(ABackendSpecific . MSSQL.ASTEquals . mkParameter <$> typedParser)
, P.fieldOptional $$(G.litName "_st_intersects")
(Just "does the column spatially intersect the given value")
(ABackendSpecific . MSSQL.ASTIntersects . mkParameter <$> typedParser)
, P.fieldOptional $$(G.litName "_st_overlaps")
(Just "does the column 'spatially overlap' (intersect but not completely contain) the given value")
(ABackendSpecific . MSSQL.ASTOverlaps . mkParameter <$> typedParser)
, P.fieldOptional $$(G.litName "_st_within")
(Just "is the column contained in the given value")
(ABackendSpecific . MSSQL.ASTWithin . mkParameter <$> typedParser)
]
-- Ops for Geometry types
, guard (isScalarColumnWhere (MSSQL.GeometryType ==) columnType) *>
[ P.fieldOptional $$(G.litName "_st_crosses")
(Just "does the column cross the given geometry value")
(ABackendSpecific . MSSQL.ASTCrosses . mkParameter <$> typedParser)
, P.fieldOptional $$(G.litName "_st_touches")
(Just "does the column have at least one point in common with the given geometry value")
(ABackendSpecific . MSSQL.ASTTouches . mkParameter <$> typedParser)
]
]
where
mkListLiteral :: [ColumnValue 'MSSQL] -> UnpreparedValue 'MSSQL
mkListLiteral =
P.UVLiteral . MSSQL.ListExpression . fmap (MSSQL.ValueExpression . cvValue)
msMkCountType
:: Maybe Bool
-- ^ distinct values
-> Maybe [Column 'MSSQL]
-> CountType 'MSSQL
msMkCountType _ Nothing = MSSQL.StarCountable
msMkCountType (Just True) (Just cols) =
maybe MSSQL.StarCountable MSSQL.DistinctCountable $ nonEmpty cols
msMkCountType _ (Just cols) =
maybe MSSQL.StarCountable MSSQL.NonNullFieldCountable $ nonEmpty cols
-- | Various update operators
msUpdateOperators
:: Applicative m
=> TableInfo 'MSSQL -- ^ table info
-> UpdPermInfo 'MSSQL -- ^ update permissions of the table
-> m (Maybe (InputFieldsParser n [(Column 'MSSQL, IR.UpdOpExpG (UnpreparedValue 'MSSQL))]))
msUpdateOperators _tableInfo _updatePermissions = pure Nothing
-- | Computed field parser.
-- Currently unsupported: returns Nothing for now.
msComputedField
:: MonadBuildSchema 'MSSQL r m n
=> SourceName
-> ComputedFieldInfo 'MSSQL
-> TableName 'MSSQL
-> SelPermInfo 'MSSQL
-> m (Maybe (FieldParser n (AnnotatedField 'MSSQL)))
msComputedField _sourceName _fieldInfo _table _selectPemissions = pure Nothing
-- | Remote join field parser.
-- Currently unsupported: returns Nothing for now.
msRemoteRelationshipField
:: MonadBuildSchema 'MSSQL r m n
=> RemoteFieldInfo 'MSSQL
-> m (Maybe [FieldParser n (AnnotatedField 'MSSQL)])
msRemoteRelationshipField _remoteFieldInfo = pure Nothing
-- | The 'node' root field of a Relay request. Relay is currently unsupported on MSSQL,
-- meaning this parser will never be called: any attempt to create this parser should
-- therefore fail.
msNode
:: MonadBuildSchema 'MSSQL r m n
=> m ( Parser 'Output n
( HashMap
( TableName 'MSSQL)
( SourceName, SourceConfig 'MSSQL
, SelPermInfo 'MSSQL
, PrimaryKeyColumns 'MSSQL
, AnnotatedFields 'MSSQL
)
)
)
msNode = throw500 "MSSQL does not support relay; `node` should never be exposed in the schema."
----------------------------------------------------------------
-- SQL literals
-- FIXME: this is nonsensical for MSSQL, we'll need to adjust the corresponding mutation
-- and its representation.
msColumnDefaultValue :: Column 'MSSQL -> SQLExpression 'MSSQL
msColumnDefaultValue = const $ MSSQL.ValueExpression ODBC.NullValue