diff --git a/glean/db/Glean/Database/Writes.hs b/glean/db/Glean/Database/Writes.hs
index 950db09a9..83ec5fb52 100644
--- a/glean/db/Glean/Database/Writes.hs
+++ b/glean/db/Glean/Database/Writes.hs
@@ -51,10 +51,12 @@ import Data.Default
 import Data.Either
 import Data.HashMap.Strict (HashMap)
 import qualified Data.HashMap.Strict as HashMap
+import qualified Data.Monoid as Monoid
 import Data.Text as Text (Text)
 import qualified Data.Text.Encoding as Text
 import qualified Data.UUID as UUID
 import qualified Data.UUID.V4 as UUID
+import qualified Data.Vector.Storable as VS
 import System.Clock
 import System.Timeout
 
@@ -289,6 +291,7 @@ enqueueBatch env ComputedBatch{..} ownership = do
   -- server restarts/crashes
   handle <- UUID.toText <$> UUID.nextRandom
 
+  let size = batchSize computedBatch_batch
   r <- try $ enqueueWrite env computedBatch_repo size $ pure $
         (writeContentFromBatch computedBatch_batch) {
           writeOwnership= ownership
@@ -301,6 +304,18 @@ enqueueBatch env ComputedBatch{..} ownership = do
      when computedBatch_remember $ rememberWrite env handle write
      return $ Thrift.SendResponse_handle handle
 
+batchSize :: Thrift.Batch -> Int
+batchSize Thrift.Batch{..} =
+  ByteString.length batch_facts +
+  Monoid.getSum (foldMap (Monoid.Sum . storableSize) batch_owned) +
+  Monoid.getSum (foldMap (Monoid.Sum . depsSize) batch_dependencies)
+  where
+  storableSize = snd . VS.unsafeToForeignPtr0
+  depsSize deps = sum
+    [ storableSize f + storableSize d
+    | FactDependencies f d <- deps
+    ]
+
 enqueueJsonBatch
   :: Env
   -> Repo
diff --git a/glean/if/glean.thrift b/glean/if/glean.thrift
index fab6ecbf2..46776b3c5 100644
--- a/glean/if/glean.thrift
+++ b/glean/if/glean.thrift
@@ -198,8 +198,8 @@ struct Fact {
 }
 
 struct FactDependencies {
-  1: list_Id_1857 facts;
-  2: list_Id_1857 dependencies;
+  1: listOfIds facts;
+  2: listOfIds dependencies;
 }
 
 // A collection of facts which can be written to a database.
@@ -228,7 +228,7 @@ struct Batch {
   //   - all elements are unique
   //   - ids are reasonably dense (writing the batch to the db will use a
   //     data structure of size O(max id - firstId))
-  4: optional list_i64_7948 ids;
+  4: optional list_i64 ids;
 
   // (optional for now)
   //
@@ -242,7 +242,7 @@ struct Batch {
   //
   // Units do not need to be declared beforehand; a Unit exists if
   // it is the owner of at least one fact.
-  5: map_UnitName_listOfIds_7119 owned;
+  5: map_UnitName_listOfIds owned;
 
   // Specifies explicit dependencies of derived facts per predicate.
   //
@@ -257,7 +257,7 @@ struct Batch {
 
 struct Subst {
   1: Id firstId;
-  2: list_i64_7948 ids;
+  2: list_i64 ids;
 }
 
 struct Error {
@@ -1294,13 +1294,10 @@ struct PredicateAnnotation {
 
 // The following were automatically generated and may benefit from renaming.
 typedef list<Fact> (hs.type = "Vector") list_Fact_2137
-typedef list<Id> (hs.type = "VectorStorable") list_Id_1857
 typedef list<Id> (hs.type = "Vector") list_Id_2029
 typedef list<ParcelState> (hs.type = "Vector") list_ParcelState_7430
-typedef list<i64> (hs.type = "VectorStorable") list_i64_7948
+typedef list<i64> (hs.type = "VectorStorable") list_i64
 typedef map<Id, list<FactDependencies>> (
   hs.type = "HashMap",
 ) map_Id_list_FactDependencies_964
-typedef map<UnitName, listOfIds> (
-  hs.type = "HashMap",
-) map_UnitName_listOfIds_7119
+typedef map<UnitName, listOfIds> (hs.type = "HashMap") map_UnitName_listOfIds