diff --git a/SVSim.Database/SVSimDbContext.cs b/SVSim.Database/SVSimDbContext.cs
index 4297621..ee226b2 100644
--- a/SVSim.Database/SVSimDbContext.cs
+++ b/SVSim.Database/SVSimDbContext.cs
@@ -403,13 +403,12 @@ public class SVSimDbContext : DbContext
         {
             b.HasKey(e => e.Id);
             b.Property(e => e.Id).ValueGeneratedOnAdd();
-            b.Property(e => e.Message).HasMaxLength(64).IsRequired();
+            b.Property(e => e.Message).HasMaxLength(64);
             b.HasOne<Viewer>()
                 .WithMany()
                 .HasForeignKey(e => e.ViewerId)
                 .OnDelete(DeleteBehavior.Cascade);
-            b.HasIndex(e => new { e.ViewerId, e.AcquireTime, e.Id })
-                .HasDatabaseName("IX_ViewerAcquireHistory_ViewerId_AcquireTime_Id");
+            b.HasIndex(e => new { e.ViewerId, e.AcquireTime, e.Id });
         });
 
         base.OnModelCreating(modelBuilder);