diff --git a/src/main/java/it/cavallium/dbengine/database/indicizer/DatabaseMemoryMode.java b/src/main/java/it/cavallium/dbengine/database/indicizer/DatabaseMemoryMode.java
new file mode 100644
index 0000000..3eed69f
--- /dev/null
+++ b/src/main/java/it/cavallium/dbengine/database/indicizer/DatabaseMemoryMode.java
@@ -0,0 +1,5 @@
+package it.cavallium.dbengine.database.indicizer;
+
+public enum DatabaseMemoryMode {
+	LOW, NORMAL, HIGH
+}
diff --git a/src/main/java/it/cavallium/dbengine/database/indicizer/Indicizer.java b/src/main/java/it/cavallium/dbengine/database/indicizer/Indicizer.java
new file mode 100644
index 0000000..ccf655c
--- /dev/null
+++ b/src/main/java/it/cavallium/dbengine/database/indicizer/Indicizer.java
@@ -0,0 +1,24 @@
+package it.cavallium.dbengine.database.indicizer;
+
+import it.cavallium.dbengine.database.LLDocument;
+import it.cavallium.dbengine.database.LLTerm;
+import java.util.Set;
+import org.jetbrains.annotations.NotNull;
+import reactor.core.publisher.Flux;
+import reactor.core.publisher.Mono;
+import reactor.util.function.Tuple2;
+
+public abstract class Indicizer<T, U> {
+
+	public abstract @NotNull Mono<LLDocument> toDocument(@NotNull T key, @NotNull U value);
+
+	public abstract @NotNull LLTerm toIndex(@NotNull T key);
+
+	public abstract @NotNull String getKeyFieldName();
+
+	public abstract @NotNull T getKey(String key);
+
+	public Flux<Tuple2<String, Set<String>>> getMoreLikeThisDocumentFields(U value) {
+		return Flux.empty();
+	}
+}
diff --git a/src/main/java/it/cavallium/dbengine/database/indicizer/JoinedIndicizerWriter.java b/src/main/java/it/cavallium/dbengine/database/indicizer/JoinedIndicizerWriter.java
new file mode 100644
index 0000000..17493e0
--- /dev/null
+++ b/src/main/java/it/cavallium/dbengine/database/indicizer/JoinedIndicizerWriter.java
@@ -0,0 +1,86 @@
+package it.cavallium.dbengine.database.indicizer;
+
+import it.cavallium.dbengine.database.LLScoreMode;
+import it.cavallium.dbengine.database.LLSearchResult;
+import it.cavallium.dbengine.database.LLSort;
+import it.cavallium.dbengine.database.collections.Joiner;
+import it.cavallium.dbengine.database.collections.Joiner.ValueGetter;
+import org.jetbrains.annotations.Nullable;
+import it.cavallium.dbengine.client.CompositeSnapshot;
+import reactor.core.publisher.Mono;
+
+public class JoinedIndicizerWriter<KEY, DBTYPE, JOINEDTYPE> implements LuceneIndicizerWriter<KEY, DBTYPE> {
+
+	private final LuceneIndicizerWriter<KEY, JOINEDTYPE> indicizerWriter;
+	private final Joiner<KEY, DBTYPE, JOINEDTYPE> joiner;
+	private final ValueGetter<KEY, DBTYPE> dbValueGetter;
+
+	public JoinedIndicizerWriter(LuceneIndicizerWriter<KEY, JOINEDTYPE> indicizerWriter,
+			Joiner<KEY, DBTYPE, JOINEDTYPE> joiner,
+			ValueGetter<KEY, DBTYPE> dbValueGetter) {
+		this.indicizerWriter = indicizerWriter;
+		this.joiner = joiner;
+		this.dbValueGetter = dbValueGetter;
+	}
+
+	@Override
+	public Mono<Void> add(KEY key, DBTYPE value) {
+		return joiner
+				.join(dbValueGetter, value)
+				.flatMap(joinedValue -> this.indicizerWriter.add(key, joinedValue));
+	}
+
+	@Override
+	public Mono<Void> remove(KEY key) {
+		return this.indicizerWriter.remove(key);
+	}
+
+	@Override
+	public Mono<Void> update(KEY key, DBTYPE value) {
+		return joiner
+				.join(dbValueGetter, value)
+				.flatMap(joinedValue -> this.indicizerWriter.update(key, joinedValue));
+	}
+
+	@Override
+	public Mono<Void> clearIndex() {
+		return this.indicizerWriter.clearIndex();
+	}
+
+	@Override
+	public Mono<LLSearchResult> moreLikeThis(@Nullable CompositeSnapshot snapshot, DBTYPE mltDocumentValue, int limit) {
+		return joiner
+				.join(dbValueGetter, mltDocumentValue)
+				.flatMap(val -> this.indicizerWriter.moreLikeThis(snapshot, val, limit));
+	}
+
+	@Override
+	public Mono<LLSearchResult> search(@Nullable CompositeSnapshot snapshot,
+			String query,
+			int limit,
+			@Nullable LLSort sort,
+			LLScoreMode scoreMode) {
+		return this.indicizerWriter
+				.search(snapshot, query, limit, sort, scoreMode);
+	}
+
+	@Override
+	public Mono<Long> count(@Nullable CompositeSnapshot snapshot, String query) {
+		return this.indicizerWriter.count(snapshot, query);
+	}
+
+	@Override
+	public Mono<Void> close() {
+		return this.indicizerWriter.close();
+	}
+
+	@Override
+	public Mono<KEY> getKey(String key) {
+		return this.indicizerWriter.getKey(key);
+	}
+
+	@Override
+	public DatabaseMemoryMode getMemoryMode() {
+		return this.indicizerWriter.getMemoryMode();
+	}
+}
diff --git a/src/main/java/it/cavallium/dbengine/database/indicizer/LuceneIndicizerWriter.java b/src/main/java/it/cavallium/dbengine/database/indicizer/LuceneIndicizerWriter.java
new file mode 100644
index 0000000..83fa986
--- /dev/null
+++ b/src/main/java/it/cavallium/dbengine/database/indicizer/LuceneIndicizerWriter.java
@@ -0,0 +1,48 @@
+package it.cavallium.dbengine.database.indicizer;
+
+import it.cavallium.dbengine.client.CompositeSnapshot;
+import it.cavallium.dbengine.database.LLScoreMode;
+import it.cavallium.dbengine.database.LLSearchResult;
+import it.cavallium.dbengine.database.LLSort;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+import reactor.core.publisher.Flux;
+import reactor.core.publisher.Mono;
+import reactor.util.function.Tuple2;
+
+public interface LuceneIndicizerWriter<T, U> {
+
+	Mono<Void> add(T key, U value);
+
+	default Mono<Void> addMulti(@NotNull Flux<Tuple2<T, U>> values) {
+		return values.flatMap(tuple -> this.add(tuple.getT1(), tuple.getT2())).then();
+	}
+
+	Mono<Void> remove(T key);
+
+	Mono<Void> update(T key, U value);
+
+	default Mono<Void> updateMulti(@NotNull Flux<Tuple2<T, U>> values) {
+		return values.flatMap(tuple -> this.update(tuple.getT1(), tuple.getT2())).then();
+	}
+
+	Mono<Void> clearIndex();
+
+	Mono<LLSearchResult> moreLikeThis(@Nullable CompositeSnapshot snapshot,
+			U mltDocumentValue,
+			int limit);
+
+	Mono<LLSearchResult> search(@Nullable CompositeSnapshot snapshot,
+			String query,
+			int limit,
+			@Nullable LLSort sort,
+			LLScoreMode scoreMode);
+
+	Mono<Long> count(@Nullable CompositeSnapshot snapshot, String query);
+
+	Mono<Void> close();
+
+	Mono<T> getKey(String key);
+
+	DatabaseMemoryMode getMemoryMode();
+}
diff --git a/src/main/java/it/cavallium/dbengine/database/indicizer/StandardLuceneIndicizerWriter.java b/src/main/java/it/cavallium/dbengine/database/indicizer/StandardLuceneIndicizerWriter.java
new file mode 100644
index 0000000..8007301
--- /dev/null
+++ b/src/main/java/it/cavallium/dbengine/database/indicizer/StandardLuceneIndicizerWriter.java
@@ -0,0 +1,92 @@
+package it.cavallium.dbengine.database.indicizer;
+
+import it.cavallium.dbengine.database.LLLuceneIndex;
+import it.cavallium.dbengine.database.LLScoreMode;
+import it.cavallium.dbengine.database.LLSearchResult;
+import it.cavallium.dbengine.database.LLSnapshot;
+import it.cavallium.dbengine.database.LLSort;
+import it.cavallium.dbengine.database.LLTerm;
+import java.util.Set;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+import it.cavallium.dbengine.client.CompositeSnapshot;
+import reactor.core.publisher.Flux;
+import reactor.core.publisher.Mono;
+import reactor.util.function.Tuple2;
+
+public class StandardLuceneIndicizerWriter<T, U> implements LuceneIndicizerWriter<T, U> {
+
+	protected final LLLuceneIndex luceneIndex;
+	protected final Indicizer<T, U> indicizer;
+
+	public StandardLuceneIndicizerWriter(@NotNull LLLuceneIndex luceneIndex, @NotNull Indicizer<T, U> indicizer) {
+		this.luceneIndex = luceneIndex;
+		this.indicizer = indicizer;
+	}
+
+	private LLSnapshot resolveSnapshot(CompositeSnapshot snapshot) {
+		if (snapshot == null) {
+			return null;
+		} else {
+			return snapshot.getSnapshot(luceneIndex);
+		}
+	}
+
+	@Override
+	public Mono<Void> add(@NotNull T key, @NotNull U value) {
+		LLTerm docKey = indicizer.toIndex(key);
+		return indicizer.toDocument(key, value).flatMap(doc -> luceneIndex.addDocument(docKey, doc));
+	}
+
+	@Override
+	public Mono<Void> remove(@NotNull T key) {
+		LLTerm term = indicizer.toIndex(key);
+		return luceneIndex.deleteDocument(term);
+	}
+
+	@Override
+	public Mono<Void> update(@NotNull T key, @NotNull U value) {
+		LLTerm term = indicizer.toIndex(key);
+		return indicizer.toDocument(key, value).flatMap(doc -> luceneIndex.updateDocument(term, doc));
+	}
+
+	@Override
+	public Mono<Void> clearIndex() {
+		return luceneIndex.deleteAll();
+	}
+
+	@Override
+	public Mono<LLSearchResult> moreLikeThis(@Nullable CompositeSnapshot snapshot, U mltDocumentValue, int limit) {
+		Flux<Tuple2<String, Set<String>>> mltDocumentFields = indicizer.getMoreLikeThisDocumentFields(mltDocumentValue);
+		return luceneIndex.moreLikeThis(resolveSnapshot(snapshot), mltDocumentFields, limit, indicizer.getKeyFieldName());
+	}
+
+	@Override
+	public Mono<LLSearchResult> search(@Nullable CompositeSnapshot snapshot,
+			String query,
+			int limit,
+			@Nullable LLSort sort,
+			LLScoreMode scoreMode) {
+		return luceneIndex.search(resolveSnapshot(snapshot), query, limit, sort, scoreMode, indicizer.getKeyFieldName());
+	}
+
+	@Override
+	public Mono<Long> count(@Nullable CompositeSnapshot snapshot, String query) {
+		return luceneIndex.count(resolveSnapshot(snapshot), query);
+	}
+
+	@Override
+	public Mono<Void> close() {
+		return luceneIndex.close();
+	}
+
+	@Override
+	public Mono<T> getKey(String key) {
+		return Mono.just(indicizer.getKey(key));
+	}
+
+	@Override
+	public DatabaseMemoryMode getMemoryMode() {
+		return luceneIndex.isLowMemoryMode() ? DatabaseMemoryMode.LOW : DatabaseMemoryMode.NORMAL;
+	}
+}