refactor: Use Neo4j transactional functions.

This change uses `session.executeWrite` and `session.executeRead` to interact with the database.
Those methods use build-in retries for several Neo4j specific error states.
Doing will improve the overall user experience in this case as the no other external retry mechanism should be used.
Doing so is fine, as the Neo4j vector store is not subject to Springs general transaction management.

Author: michael-simons

vector-stores/spring-ai-neo4j-store/src/main/java/org/springframework/ai/vectorstore/Neo4jVectorStore.java

@@ -119,7 +119,9 @@ public void doAdd(List<Document> documents) {
 						WITH row, u
 						CALL db.create.setNodeVectorProperty(u, $embeddingProperty, row.embedding)
 					""".formatted(this.config.label, this.config.idProperty);
-			session.run(statement, Map.of("rows", rows, "embeddingProperty", this.config.embeddingProperty)).consume();
+			session.executeWrite(
+					tx -> tx.run(statement, Map.of("rows", rows, "embeddingProperty", this.config.embeddingProperty))
+						.consume());
 		}
 	}
 
@@ -128,6 +130,8 @@ public Optional<Boolean> doDelete(List<String> idList) {
 
 		try (var session = this.driver.session(this.config.sessionConfig)) {
 
+			// Those queries with internal, cypher based transaction management cannot be
+			// run with executeWrite
 			var summary = session
 				.run("""
 						MATCH (n:%s) WHERE n.%s IN $ids
@@ -158,10 +162,10 @@ public List<Document> doSimilaritySearch(SearchRequest request) {
 					WHERE %s
 					RETURN node, score""".formatted(condition);
 
-			return session
+			return session.executeRead(tx -> tx
 				.run(query, Map.of("indexName", this.config.indexNameNotSanitized, "numberOfNearestNeighbours",
 						request.getTopK(), "embeddingValue", embedding, "threshold", request.getSimilarityThreshold()))
-				.list(this::recordToDocument);
+				.list(this::recordToDocument));
 		}
 	}
 
@@ -174,20 +178,22 @@ public void afterPropertiesSet() {
 
 		try (var session = this.driver.session(this.config.sessionConfig)) {
 
-			session
-				.run("CREATE CONSTRAINT %s IF NOT EXISTS FOR (n:%s) REQUIRE n.%s IS UNIQUE"
-					.formatted(this.config.constraintName, this.config.label, this.config.idProperty))
-				.consume();
-
-			var statement = """
-					CREATE VECTOR INDEX %s IF NOT EXISTS FOR (n:%s) ON (n.%s)
-							OPTIONS {indexConfig: {
-							`vector.dimensions`: %d,
-							`vector.similarity_function`: '%s'
-							}}
-					""".formatted(this.config.indexName, this.config.label, this.config.embeddingProperty,
-					this.config.embeddingDimension, this.config.distanceType.name);
-			session.run(statement).consume();
+			session.executeWriteWithoutResult(tx -> {
+				tx.run("CREATE CONSTRAINT %s IF NOT EXISTS FOR (n:%s) REQUIRE n.%s IS UNIQUE"
+					.formatted(this.config.constraintName, this.config.label, this.config.idProperty)).consume();
+
+				var statement = """
+						CREATE VECTOR INDEX %s IF NOT EXISTS FOR (n:%s) ON (n.%s)
+								OPTIONS {indexConfig: {
+								`vector.dimensions`: %d,
+								`vector.similarity_function`: '%s'
+								}}
+						""".formatted(this.config.indexName, this.config.label, this.config.embeddingProperty,
+						this.config.embeddingDimension, this.config.distanceType.name);
+				tx.run(statement).consume();
+			});
+
+			// Bad idea to retry this...
 			session.run("CALL db.awaitIndexes()").consume();
 		}
 	}