diff --git a/pwiz_tools/Skyline/Model/Lib/EncylopeDiaLibrary.cs b/pwiz_tools/Skyline/Model/Lib/EncylopeDiaLibrary.cs
index a8858f1ecc..3559bcba32 100644
--- a/pwiz_tools/Skyline/Model/Lib/EncylopeDiaLibrary.cs
+++ b/pwiz_tools/Skyline/Model/Lib/EncylopeDiaLibrary.cs
@@ -157,62 +157,36 @@ public override LibraryDetails LibraryDetails
         {
             get
             {
-                var detailsByFileName = new Dictionary<string, SpectrumSourceFileDetails>();
-
-                try
+                return new LibraryDetails
                 {
-                    lock (_pooledSqliteConnection)
-                    {
-                        using (var select = new SQLiteCommand(_pooledSqliteConnection.Connection))
-                        {
-                            // ReSharper disable LocalizableElement
-
-                            // Query for the source files detail information.
-                            select.CommandText = @"select one.SourceFile, BestSpectra, MatchedSpectra
-from (
-  select SourceFile, count(*) as MatchedSpectra
-  from entries as s
-  group by SourceFile) as one
-inner join (
-  select SourceFile, count(*) as BestSpectra
-  from entries as e
-  where Score = (select min(Score) from entries where e.PeptideModSeq = PeptideModSeq AND e.PrecursorCharge = PrecursorCharge)
-  group by SourceFile) as two
-on one.SourceFile = two.SourceFile";
-
-                            // ReSharper restore LocalizableElement
-                            using (SQLiteDataReader reader = select.ExecuteReader())
-                            {
-                                while (reader.Read())
-                                {
-                                    string filename = reader.GetString(0);
-                                    var fileDetails = new SpectrumSourceFileDetails(filename);
-                                    fileDetails.ScoreThresholds.Add(ScoreType.GenericQValue, null);
-                                    fileDetails.BestSpectrum = Convert.ToInt32(reader.GetValue(1));
-                                    fileDetails.MatchedSpectrum = Convert.ToInt32(reader.GetValue(2));
-                                    detailsByFileName.Add(filename, fileDetails);
-                                }
-                            }
-                        }
-                    }
-                }
-                catch (Exception)
+                    DataFiles = EnumerateSpectrumSourceFileDetails().ToList()
+                    // Consider: UniquePeptideCount, SpectrumCount
+                };
+            }
+        }
+
+        private IEnumerable<SpectrumSourceFileDetails> EnumerateSpectrumSourceFileDetails()
+        {
+            var bestSpectrumCounts = new int[LibraryFiles.Count];
+            var matchedSpectrumCounts = new int[LibraryFiles.Count];
+            foreach (var entry in _libraryEntries)
+            {
+                bestSpectrumCounts[entry.BestFileId]++;
+                foreach (var fileData in entry.FileDatas)
                 {
-                    // Do nothing more. Simply return any details collected or minimum information.
+                    matchedSpectrumCounts[fileData.Key]++;
                 }
+            }
 
-                return new LibraryDetails
+            for (int iFile = 0; iFile < LibraryFiles.Count; iFile++)
+            {
+                var details = new SpectrumSourceFileDetails(LibraryFiles[iFile])
                 {
-                    DataFiles = _sourceFiles.Select(file =>
-                    {
-                        if (!detailsByFileName.TryGetValue(file, out var fileDetails))
-                        {
-                            fileDetails = new SpectrumSourceFileDetails(file);
-                            fileDetails.ScoreThresholds.Add(ScoreType.GenericQValue, null);
-                        }
-                        return fileDetails;
-                    })
+                    BestSpectrum = bestSpectrumCounts[iFile],
+                    MatchedSpectrum = matchedSpectrumCounts[iFile],
                 };
+                details.ScoreThresholds.Add(ScoreType.GenericQValue, null);
+                yield return details;
             }
         }
 
diff --git a/pwiz_tools/Skyline/Model/Lib/Library.cs b/pwiz_tools/Skyline/Model/Lib/Library.cs
index 192f1305d9..99efe194c9 100644
--- a/pwiz_tools/Skyline/Model/Lib/Library.cs
+++ b/pwiz_tools/Skyline/Model/Lib/Library.cs
@@ -2829,7 +2829,7 @@ public override string ToString()
     public sealed class LibraryDetails
     {
         private readonly IList<LibraryLink> _libLinks;
-        private IEnumerable<SpectrumSourceFileDetails> _dataFiles;
+        private ImmutableList<SpectrumSourceFileDetails> _dataFiles = ImmutableList<SpectrumSourceFileDetails>.EMPTY;
         
         public LibraryDetails()
         {
@@ -2856,8 +2856,8 @@ public void AddLink(LibraryLink link)
         public int TotalPsmCount { get; set; }
         public IEnumerable<SpectrumSourceFileDetails> DataFiles
         { 
-            get { return _dataFiles ?? (_dataFiles = new List<SpectrumSourceFileDetails>()); }
-            set { _dataFiles = value; }
+            get { return _dataFiles; }
+            set { _dataFiles = ImmutableList.ValueOfOrEmpty(value); }
         }
 
         public IEnumerable<LibraryLink> LibLinks