Explain what the "database or disk is full" error means to the user

source/AirGQL/Lib.hs

@@ -36,6 +36,7 @@ module AirGQL.Lib (
   lintTableCreationCode,
   resolveReferencesConstraintColumns,
   resolveReferencesConstraint,
+  sqliteErrorToText,
 )
 where
 
@@ -689,7 +690,10 @@ lintTable allEntries parsed =
 
 An optional connection can be used to retrieve the existing db data, which
 is used for things like resolving implicit references constraints (where
-the primary key is not explicitly given)
+the primary key is not explicitly given).
+
+The connection is optional to allow calling this function on-the-fly when
+creating the initial table in a databse.
 -}
 lintTableCreationCode :: Maybe SS.Connection -> Statement -> IO [Text]
 lintTableCreationCode connectionMb statement = do
@@ -1309,3 +1313,19 @@ instance FromJSON SQLPost
 
 instance ToSample AirGQL.Lib.SQLPost where
   toSamples _ = singleSample $ SQLPost "SELECT * FROM users"
+
+
+-- | Converts an sql error to text, possibly adding airsequel-specific context.
+sqliteErrorToText :: SS.SQLError -> Text
+sqliteErrorToText error =
+  let
+    addendum = case SS.sqlErrorDetails error of
+      "database or disk is full" ->
+        Just $
+          "This might be caused by the database exceeding "
+            <> "the maximum page count for your current plan."
+      _ -> Nothing
+  in
+    show error <> case addendum of
+      Nothing -> ""
+      Just text -> "\n" <> text

source/AirGQL/Servant/SqlQuery.hs

@@ -42,6 +42,7 @@ import AirGQL.Lib (
   lintTableCreationCode,
   parseSql,
   sqlDataToAesonValue,
+  sqliteErrorToText,
  )
 import AirGQL.Types.PragmaConf (PragmaConf, getSQLitePragmas)
 import AirGQL.Types.SqlQueryPostResult (
@@ -150,7 +151,7 @@ sqlQueryPostHandler pragmaConf dbId sqlPost = do
           P.catches
             performSqlOperations
             [ P.Handler $
-                \(error :: SS.SQLError) -> pure $ Left $ show error
+                \(error :: SS.SQLError) -> pure $ Left $ sqliteErrorToText error
             , P.Handler $
                 \(error :: SS.ResultError) -> pure $ Left $ show error
             , P.Handler $

source/AirGQL/Types/PragmaConf.hs

@@ -7,10 +7,8 @@ where
 
 import Protolude (
   Bool (True),
-  IO,
   Int,
   Integer,
-  pure,
   show,
   ($),
   (<>),