Add a couple of indexes to the database to speed up searches on large libraries.

data/data.qrc

@@ -71,5 +71,6 @@
         <file>media-playlist-repeat-off.png</file>
         <file>media-playlist-shuffle-off.png</file>
         <file>schema-4.sql</file>
+        <file>schema-5.sql</file>
     </qresource>
 </RCC>

data/schema-5.sql

@@ -0,0 +1,8 @@
+ALTER TABLE songs ADD COLUMN effective_compilation NOT NULL DEFAULT 0;
+
+UPDATE songs SET effective_compilation = ((compilation OR sampler OR forced_compilation_on) AND NOT forced_compilation_off) + 0;
+
+CREATE INDEX idx_comp_artist ON songs (effective_compilation, artist);
+
+UPDATE schema_version SET version=5;
+

src/librarybackend.cpp

@@ -16,7 +16,7 @@
 
 
 const char* LibraryBackend::kDatabaseName = "clementine.db";
-const int LibraryBackend::kSchemaVersion = 4;
+const int LibraryBackend::kSchemaVersion = 5;
 
 void (*LibraryBackend::_sqlite3_create_function) (
     sqlite3*, const char*, int, int, void*,
@@ -535,7 +535,10 @@ void LibraryBackend::UpdateCompilations() {
   }
 
   // Now mark the songs that we think are in compilations
-  QSqlQuery update("UPDATE songs SET sampler = :sampler WHERE album = :album", db);
+  QSqlQuery update("UPDATE songs"
+                   " SET sampler = :sampler,"
+                   "     effective_compilation = ((compilation OR :sampler OR forced_compilation_on) AND NOT forced_compilation_off) + 0"
+                   " WHERE album = :album", db);
   QSqlQuery find_songs("SELECT ROWID, " + QString(Song::kColumnSpec) + " FROM songs"
                        " WHERE album = :album AND sampler = :sampler", db);
 
@@ -629,6 +632,7 @@ LibraryBackend::AlbumList LibraryBackend::GetAlbums(const QString& artist,
     last_album = info.album_name;
     last_artist = info.artist;
   }
+
   return ret;
 }
 

src/libraryquery.cpp

@@ -41,12 +41,7 @@ void LibraryQuery::AddWhere(const QString& column, const QVariant& value) {
 }
 
 void LibraryQuery::AddCompilationRequirement(bool compilation) {
-  if (compilation)
-    where_clauses_ << "((compilation = 1 OR sampler = 1 OR forced_compilation_on = 1)"
-                      " AND forced_compilation_off = 0)";
-  else
-    where_clauses_ << "((compilation = 0 AND sampler = 0 AND forced_compilation_on = 0)"
-                      " OR forced_compilation_off = 1)";
+  where_clauses_ << QString("effective_compilation = %1").arg(compilation ? 1 : 0);
 }
 
 QSqlQuery LibraryQuery::Query(QSqlDatabase db) const {

src/song.cpp

@@ -40,7 +40,7 @@ const char* Song::kColumnSpec =
     "length, bitrate, samplerate, directory, filename, "
     "mtime, ctime, filesize, sampler, art_automatic, art_manual, "
     "filetype, playcount, lastplayed, rating, forced_compilation_on, "
-    "forced_compilation_off";
+    "forced_compilation_off, effective_compilation";
 
 const char* Song::kBindSpec =
     ":title, :album, :artist, :albumartist, :composer, "
@@ -48,7 +48,7 @@ const char* Song::kBindSpec =
     ":length, :bitrate, :samplerate, :directory_id, :filename, "
     ":mtime, :ctime, :filesize, :sampler, :art_automatic, :art_manual, "
     ":filetype, :playcount, :lastplayed, :rating, :forced_compilation_on, "
-    ":forced_compilation_off";
+    ":forced_compilation_off, :effective_compilation";
 
 const char* Song::kUpdateSpec =
     "title = :title, album = :album, artist = :artist, "
@@ -61,7 +61,8 @@ const char* Song::kUpdateSpec =
     "art_automatic = :art_automatic, art_manual = :art_manual, "
     "filetype = :filetype, playcount = :playcount, lastplayed = :lastplayed, "
     "rating = :rating, forced_compilation_on = :forced_compilation_on, "
-    "forced_compilation_off = :forced_compilation_off";
+    "forced_compilation_off = :forced_compilation_off, "
+    "effective_compilation = :effective_compilation";
 
 TagLibFileRefFactory Song::kDefaultFactory;
 
@@ -302,6 +303,8 @@ void Song::InitFromQuery(const QSqlQuery& q) {
   d->forced_compilation_on_ = q.value(28).toBool();
   d->forced_compilation_off_ = q.value(29).toBool();
 
+  // effective_compilation = 30
+
   #undef tostr
   #undef toint
   #undef tofloat
@@ -373,6 +376,8 @@ void Song::BindToQuery(QSqlQuery *query) const {
   query->bindValue(":forced_compilation_on", d->forced_compilation_on_ ? 1 : 0);
   query->bindValue(":forced_compilation_off", d->forced_compilation_off_ ? 1 : 0);
 
+  query->bindValue(":effective_compilation", is_compilation() ? 1 : 0);
+
   #undef intval
 }