1 files changed, 8 insertions, 1 deletions
diff --git a/src/mongo/db/query/sbe_plan_cache.h b/src/mongo/db/query/sbe_plan_cache.h
index 6e7853fa817..090df251bdf 100644
--- a/src/mongo/db/query/sbe_plan_cache.h
+++ b/src/mongo/db/query/sbe_plan_cache.h
@@ -190,7 +190,14 @@ struct CachedSbePlan {
 using PlanCacheEntry = PlanCacheEntryBase<CachedSbePlan, plan_cache_debug_info::DebugInfoSBE>;
 
 struct BudgetEstimator {
-    size_t operator()(const std::shared_ptr<const PlanCacheEntry>& entry) {
+    /**
+     * This estimator function is called when an entry is added or removed to LRU cache in order to
+     * make sure the total plan cache size does not exceed the maximum size.
+     */
+    size_t operator()(const sbe::PlanCacheKey& key,
+                      const std::shared_ptr<const PlanCacheEntry>& entry) {
+        // TODO: SERVER-73649 include size of underlying query shape and size of int_32 key hash in
+        // total size estimation.
         return entry->estimatedEntrySizeBytes;
     }
 };