refactor: get rid of dbQueryTimings from SchemaCache

src/PostgREST/AppState.hs

@@ -351,7 +351,7 @@ retryingSchemaCacheLoad appState@AppState{stateObserver=observer, stateMainThrea
           observer $ SchemaCacheErrorObs configDbSchemas configDbExtraSearchPath e
           return Nothing
 
-        Right sCache -> do
+        Right (sCache, queryTimings) -> do
           -- IMPORTANT: While the pending schema cache state starts from running the above querySchemaCache, only at this stage we block API requests due to the usage of an
           -- IORef on putSchemaCache. This is why schema cache status is marked as pending here to signal the Admin server (using isPending) that we're on a recovery state.
           markSchemaCachePending appState
@@ -361,7 +361,7 @@ retryingSchemaCacheLoad appState@AppState{stateObserver=observer, stateMainThrea
           -- We do it after successfully querying the schema cache (because this can fail and during retries we would flush the pool repeatedly unnecessarily)
           -- and after marking sCacheStatus as pending,
           flushPool appState
-          observer $ SchemaCacheQueriedObs resultTime $ dbQueryTimings sCache
+          observer $ SchemaCacheQueriedObs resultTime queryTimings
           observer $ SchemaCacheLoadedObs loadTime summary
           markSchemaCacheLoaded appState
           return $ Just sCache

src/PostgREST/CLI.hs

@@ -68,7 +68,7 @@ dumpSchema appState = do
       let observer = AppState.getObserver appState
       observer $ SchemaCacheErrorObs configDbSchemas configDbExtraSearchPath e
       exitFailure
-    Right sCache -> return $ JSON.encode sCache
+    Right (sCache, _) -> return $ JSON.encode sCache
 
 -- | Command line interface options
 data CLI = CLI

src/PostgREST/SchemaCache.hs

@@ -89,11 +89,10 @@ data SchemaCache = SchemaCache
   -- Since index construction can be expensive, we build it once and store in the SchemaCache
   -- Haskell lazy evaluation ensures it's only built on first use and memoized afterwards
   , dbTablesFuzzyIndex :: TablesFuzzyIndex
-  , dbQueryTimings     :: Maybe QueryTimings -- ^ cached time for the time each query took when debugging
   } deriving (Show)
 
 instance JSON.ToJSON SchemaCache where
-  toJSON (SchemaCache tabs rels routs reps hdlers tzs _ _) = JSON.object [
+  toJSON (SchemaCache tabs rels routs reps hdlers tzs _) = JSON.object [
       "dbTables"          .= JSON.toJSON tabs
     , "dbRelationships"   .= JSON.toJSON rels
     , "dbRoutines"        .= JSON.toJSON routs
@@ -103,7 +102,7 @@ instance JSON.ToJSON SchemaCache where
     ]
 
 showSummary :: SchemaCache -> Text
-showSummary (SchemaCache tbls rels routs reps mediaHdlrs tzs _ _) =
+showSummary (SchemaCache tbls rels routs reps mediaHdlrs tzs _) =
   T.intercalate ", "
   [ show (HM.size tbls)       <> " Relations"
   , show (HM.size rels)       <> " Relationships"
@@ -154,7 +153,7 @@ type SqlQuery = ByteString
 maxDbTablesForFuzzySearch :: Int
 maxDbTablesForFuzzySearch = 500
 
-querySchemaCache :: AppConfig -> SQL.Transaction SchemaCache
+querySchemaCache :: AppConfig -> SQL.Transaction (SchemaCache, Maybe QueryTimings)
 querySchemaCache conf@AppConfig{..} = do
   SQL.sql "set local schema ''" -- This voids the search path. The following queries need this for getting the fully qualified name(schema.name) of every db object
   tabs    <- sqlTimedStmt gucTbls  conf   allTables
@@ -179,7 +178,7 @@ querySchemaCache conf@AppConfig{..} = do
   let tabsWViewsPks = addViewPrimaryKeys tabs keyDeps
       rels          = addInverseRels $ addM2MRels tabsWViewsPks $ addViewM2OAndO2ORels keyDeps m2oRels
 
-  return $ removeInternal schemas $ SchemaCache {
+  return (removeInternal schemas $ SchemaCache {
       dbTables = tabsWViewsPks
     , dbRelationships = getOverrideRelationshipsMap rels cRels
     , dbRoutines = funcs
@@ -191,8 +190,7 @@ querySchemaCache conf@AppConfig{..} = do
         -- Only build fuzzy index for schemas with a reasonable number of tables
         -- Fuzzy.FuzzySet is memory heavy we just don't use it for large schemas
         Fuzzy.fromList <$> HM.filter ((< maxDbTablesForFuzzySearch) . length) (HM.fromListWith (<>) ((qiSchema &&& pure . qiName) <$> HM.keys tabsWViewsPks))
-    , dbQueryTimings = qsTime
-    }
+    }, qsTime)
   where
     schemas = toList configDbSchemas
     isLogDebug = configLogLevel == LogDebug
@@ -230,7 +228,6 @@ removeInternal schemas dbStruct =
     , dbMediaHandlers   = dbMediaHandlers dbStruct
     , dbTimezones       = dbTimezones dbStruct
     , dbTablesFuzzyIndex = dbTablesFuzzyIndex dbStruct
-    , dbQueryTimings      = dbQueryTimings dbStruct
     }
   where
     hasInternalJunction ComputedRelationship{} = False

test/observability/Main.hs

@@ -71,4 +71,4 @@ main = do
 
   where
     loadSCache pool conf =
-      either (panic.show) id <$> P.use pool (HT.transaction HT.ReadCommitted HT.Read $ querySchemaCache conf)
+      either (panic.show) fst <$> P.use pool (HT.transaction HT.ReadCommitted HT.Read $ querySchemaCache conf)

test/spec/Main.hs

@@ -289,4 +289,4 @@ main = do
 
   where
     loadSCache pool conf =
-      either (panic.show) id <$> P.use pool (HT.transaction HT.ReadCommitted HT.Read $ querySchemaCache conf)
+      either (panic.show) fst <$> P.use pool (HT.transaction HT.ReadCommitted HT.Read $ querySchemaCache conf)