diff --git a/src/execution/indexer.rs b/src/execution/indexer.rs
index cf07ace2..90746a55 100644
--- a/src/execution/indexer.rs
+++ b/src/execution/indexer.rs
@@ -116,6 +116,7 @@ struct TrackingInfoForTarget<'a> {
     mutation: ExportTargetMutation,
 }
 
+#[derive(Debug)]
 struct PrecommitData<'a> {
     scope_value: &'a ScopeValueBuilder,
     memoization_info: &'a MemoizationInfo,
@@ -174,10 +175,12 @@ async fn precommit_source_tracking_info(
             .or_default()
             .export_op = Some(export_op);
     }
+
+    // Collect `tracking_info_for_targets` from existing tracking info.
     if let Some(info) = tracking_info {
         let sqlx::types::Json(staging_target_keys) = info.staging_target_keys;
         for (target_id, keys_info) in staging_target_keys.into_iter() {
-            let mut target_info = TrackingInfoForTarget::default();
+            let target_info = tracking_info_for_targets.entry(target_id).or_default();
             for key_info in keys_info.into_iter() {
                 target_info
                     .existing_staging_keys_info
@@ -185,7 +188,6 @@ async fn precommit_source_tracking_info(
                     .or_default()
                     .push((key_info.1, key_info.2));
             }
-            tracking_info_for_targets.insert(target_id, target_info);
         }
 
         if let Some(sqlx::types::Json(target_keys)) = info.target_keys {
@@ -378,7 +380,6 @@ async fn commit_source_tracking_info(
                 .collect::<Vec<_>>()
         })
         .unwrap_or_default();
-
     if !precommit_metadata.source_entry_exists && cleaned_staging_target_keys.is_empty() {
         // TODO: When we support distributed execution in the future, we'll need to leave a tombstone for a while
         // to prevent an earlier update causing the record reappear because of out-of-order processing.
@@ -532,21 +533,17 @@ pub async fn update_source_entry(
 
     // Phase 3: Apply changes to the target storage, including upserting new target records and removing existing ones.
     let mut target_mutations = precommit_output.target_mutations;
-    let apply_futs = plan
-        .export_ops
-        .iter()
-        .filter_map(|export_op| {
-            target_mutations
-                .remove(&export_op.target_id)
-                .and_then(|mutation| {
-                    if !mutation.is_empty() {
-                        Some(export_op.executor.apply_mutation(mutation))
-                    } else {
-                        None
-                    }
-                })
-        })
-        .collect::<Vec<_>>();
+    let apply_futs = plan.export_ops.iter().filter_map(|export_op| {
+        target_mutations
+            .remove(&export_op.target_id)
+            .and_then(|mutation| {
+                if !mutation.is_empty() {
+                    Some(export_op.executor.apply_mutation(mutation))
+                } else {
+                    None
+                }
+            })
+    });
 
     // TODO: Handle errors.
     try_join_all(apply_futs).await?;