1 files changed, 7 insertions, 0 deletions
diff --git a/src/index/base.h b/src/index/base.h
index 74bc1ebfd2..8559e3cb64 100644
--- a/src/index/base.h
+++ b/src/index/base.h
@@ -27,6 +27,13 @@ struct IndexSummary {
 class BaseIndex : public CValidationInterface
 {
 protected:
+    /**
+     * The database stores a block locator of the chain the database is synced to
+     * so that the index can efficiently determine the point it last stopped at.
+     * A locator is used instead of a simple hash of the chain tip because blocks
+     * and block index entries may not be flushed to disk until after this database
+     * is updated.
+    */
     class DB : public CDBWrapper
     {
     public: