Oracle Graph: Graph Features of Oracle Database



Similar documents
Graph Database Performance: An Oracle Perspective

Oracle Spatial and Graph

Mining Big Data with RDF Graph Technology:

Oracle Spatial and Graph. Jayant Sharma Director, Product Management

How To Use An Orgode Database With A Graph Graph (Robert Kramer)

Geospatial Platforms For Enabling Workflows

Ching-Yung Lin, Ph.D. Adjunct Professor, Dept. of Electrical Engineering and Computer Science IBM Chief Scientist, Graph Computing. October 29th, 2015

Geospatial Platforms For Enabling Workflows

Smart Cities require Geospatial Data Providing services to citizens, enterprises, visitors...

Geospatial Technology Innovations and Convergence

Semantic Data Management. Xavier Lopez, Ph.D., Director, Spatial & Semantic Technologies

Application of OASIS Integrated Collaboration Object Model (ICOM) with Oracle Database 11g Semantic Technologies

! E6893 Big Data Analytics Lecture 9:! Linked Big Data Graph Computing (I)

Introduction to Ontologies

Big Data, Cloud Computing, Spatial Databases Steven Hagan Vice President Server Technologies

Oracle Big Data SQL Technical Update

2009 Oracle Corporation 1

Cray: Enabling Real-Time Discovery in Big Data

Oracle Database - Engineered for Innovation. Sedat Zencirci Teknoloji Satış Danışmanlığı Direktörü Türkiye ve Orta Asya

An Integrated Analytics & Big Data Infrastructure September 21, 2012 Robert Stackowiak, Vice President Data Systems Architecture Oracle Enterprise

Achieving Real-Time Business Solutions Using Graph Database Technology and High Performance Networks

Oracle s Big Data solutions. Roger Wullschleger. <Insert Picture Here>

Complexity and Scalability in Semantic Graph Analysis Semantic Days 2013

Executive Summary... 2 Introduction Defining Big Data The Importance of Big Data... 4 Building a Big Data Platform...

Oracle Database 12c Plug In. Switch On. Get SMART.

Big Data for Official Statistics Processing Big and Fast Data Optimizing Results with a Multi-Model Database

Unstructured Data Management with Oracle Database 12c O R A C L E W H I T E P A P E R S E P T E M B E R

Oracle Primavera P6 Enterprise Project Portfolio Management Performance and Sizing Guide. An Oracle White Paper October 2010

Big Graph Processing: Some Background

Storage and Retrieval of Large RDF Graph Using Hadoop and MapReduce

The Semantic Web for Application Developers. Oracle New England Development Center Zhe Wu, Ph.D. 1

An Oracle White Paper July Oracle Primavera Contract Management, Business Intelligence Publisher Edition-Sizing Guide

XTM Web 2.0 Enterprise Architecture Hardware Implementation Guidelines. A.Zydroń 18 April Page 1 of 12

Benchmarking the Performance of Storage Systems that expose SPARQL Endpoints

Big Data and Analytics: Challenges and Opportunities

SUN ORACLE EXADATA STORAGE SERVER

Inge Os Sales Consulting Manager Oracle Norway

An Oracle White Paper June High Performance Connectors for Load and Access of Data from Hadoop to Oracle Database

Taming Big Data Variety with Semantic Graph Databases. Evren Sirin CTO Complexible

LDIF - Linked Data Integration Framework

Deploying a Geospatial Cloud

Big Data and Analytics: Getting Started with ArcGIS. Mike Park Erik Hoel

Oracle Database 11g Comparison Chart

Oracle Big Data Spatial & Graph Social Network Analysis - Case Study

Exadata Database Machine

Unstructured Data Accelerator (UDA) Author: Motti Beck, Mellanox Technologies Date: March 27, 2012

GRAPH DATABASE SYSTEMS. h_da Prof. Dr. Uta Störl Big Data Technologies: Graph Database Systems - SoSe

Network Graph Databases, RDF, SPARQL, and SNA

Integrating Open Sources and Relational Data with SPARQL

THE SEMANTIC WEB AND IT`S APPLICATIONS

News and trends in Data Warehouse Automation, Big Data and BI. Johan Hendrickx & Dirk Vermeiren

LINKED DATA EXPERIENCE AT MACMILLAN Building discovery services for scientific and scholarly content on top of a semantic data model

Semantic Stored Procedures Programming Environment and performance analysis

Cloud Computing through Virtualization and HPC technologies

Accelerating Enterprise Applications and Reducing TCO with SanDisk ZetaScale Software

Safe Harbor Statement

Oracle Exadata: The World s Fastest Database Machine Exadata Database Machine Architecture

PSAM, NEC PCIe SSD Appliance for Microsoft SQL Server (Reference Architecture) September 11 th, 2014 NEC Corporation

The use of Semantic Web Technologies in Spatial Decision Support Systems

Why NoSQL? Your database options in the new non- relational world IBM Cloudant 1

Big Data, Fast Data, Complex Data. Jans Aasman Franz Inc

Safe Harbor Statement

Oracle Big Data Handbook

Optimize Oracle Business Intelligence Analytics with Oracle 12c In-Memory Database Option

Analytics March 2015 White paper. Why NoSQL? Your database options in the new non-relational world

COMP9321 Web Application Engineering

Where is... How do I get to...

How To Build A Cloud Based Intelligence System

Oracle Big Data Spatial and Graph

Using OBIEE for Location-Aware Predictive Analytics

Oracle Database Public Cloud Services

Maximizing Hadoop Performance and Storage Capacity with AltraHD TM

An Oracle White Paper October Oracle: Big Data for the Enterprise

Oracle BI EE Implementation on Netezza. Prepared by SureShot Strategies, Inc.

An Oracle White Paper February Managing Unstructured Data with Oracle Database 11g

Converged storage architecture for Oracle RAC based on NVMe SSDs and standard x86 servers

E6895 Advanced Big Data Analytics Lecture 4:! Data Store

Overview on Graph Datastores and Graph Computing Systems. -- Litao Deng (Cloud Computing Group)

Yet Another Triple Store Benchmark? Practical Experiences with Real-World Data

Business white paper. HP Process Automation. Version 7.0. Server performance

Capacity Management for Oracle Database Machine Exadata v2

Supercomputing and Big Data: Where are the Real Boundaries and Opportunities for Synergy?

An Ontological Approach to Oracle BPM

Semantic Modeling with RDF. DBTech ExtWorkshop on Database Modeling and Semantic Modeling Lili Aunimo

Oracle Database In-Memory The Next Big Thing

A Platform for Supporting Data Analytics on Twitter: Challenges and Objectives 1

How To Make Sense Of Data With Altilia

Design and Implementation of a Semantic Web Solution for Real-time Reservoir Management

An Approach to Implement Map Reduce with NoSQL Databases

Bigdata : Enabling the Semantic Web at Web Scale

Preview of Oracle Database 12c In-Memory Option. Copyright 2013, Oracle and/or its affiliates. All rights reserved.

NoSQL and Graph Database

White Paper: Big Data and the hype around IoT

<Insert Picture Here> Oracle Database Directions Fred Louis Principal Sales Consultant Ohio Valley Region

bigdata Managing Scale in Ontological Systems

Transcription:

Oracle Graph: Graph Features of Oracle Database 12c Zhe Wu alan.wu@oracle.com Ph.D., Architect Oracle Spatial & Graph Feb, 2014

The following is intended to outline our general product direction. It is intended for information purposes only, and may not be incorporated into any contract. It is not a commitment to deliver any material, code, or functionality, and should not be relied upon in making purchasing decisions. The development, release, and timing of any features or functionality described for Oracle s products remains at the sole discretion of Oracle. 2

Unstructured Data Support in Oracle Database Oracle 8 Oracle 8i Oracle 9i Oracle Database 10g Oracle Database 11g VLDB Text XML DB Network Graphs SecureFile LOBs LOBs Spatial RDF Graphs DBFS Extensibility Image Audio Raster Imagery XQUERY DICOM Medical Imagery Oracle Spatial and Graph Video BINARY XML 3

Unstructured Data Device-generated data Documents Location data Audio, Video, Image Social Network and Interaction Models 4

Oracle Database Support for Unstructured Data Optimized Storage Specialized Data Types Administration & Management Indexing and Query Powerful Analytics 5

Oracle Database Support for Unstructured Data Graph Analysis Spatial Analytics XML Query Text and Search SQL Analytics Parallel Processing Engine XML Relational RDF Graph Spatial Data Layer SecureFiles Network Graph Multimedia 6

Introduction to Graph Concept & Graph Data Models 7 7

Overview of Graph What is a graph? A set of vertexes and edges (and optionally attributes) A graph is simply linked data C Why do we care? Graphs are everywhere A D Road networks, power grids, biological networks F Social networks/social Web (Facebook, Linkedin, Twitter, Baidu, Google+, ) Knowledge graphs (RDF, OWL) Graphs are intuitive and flexible Easy to navigate, easy to form a path, natural to visualize Do not require a predefined schema B E 8

Various Kinds of Graphs There are more than one kind of graph Simple graph, Weighted graph, Vertex-labeled graph, Edge-labeled graph, Directed graph (digraph), Undirected graph, Hypergraph, Different application scenarios Link-node graphs representing physical/logical networks used in transportation, utilities and telco RDF Semantic Graphs modeling data as triples for social network, linked data and other semantic applications Property Graphs allowing the association of K/V pairs with vertexes/edges 9

Graph Data Model 1: RDF Semantic Graph Resource Description Framework URIs are used to identify Resources, entities, relationships, concepts Data identification is a must for integration RDF Graph defines semantics Standards defined by W3C & OGC RDF, RDFS, OWL, SKOS SPARQL, RDFa, RDB2RDF, GeoSPARQL Implementations Oracle, IBM, Cray, Bigdata Franz, Ontotext, Openlink, Jena, Sesame, 10

Graph Data Model 2: Property Graph A set of vertices (or nodes) each vertex has a unique identifier. each vertex has a set of in/out edges. each vertex has a collection of key-value properties. A set of edges each edge has a unique identifier. each edge has a head/tail vertex. each edge has a label denoting type of relationship between two vertices. each edge has a collection of key-value properties. Blueprints Java APIs Implementations Neo4j, Titan, InfiniteGraph, Dex, Sail, MongoDB A property graph can be modeled as an RDF Graph 11 https://github.com/tinkerpop/blueprints/wiki/property-graph-model

Graphs Are Big and Are Getting Bigger Social Scale* 1 Billion vertices, 100 billion edges Web Scale* 50 billion vertices, 1 trillion edges Brain Scale* 100 billion vertices, 100 trillion edges 12 * An NSA Big Graph Experiment http://www.pdl.cmu.edu/sdi/2013/slides/big_graph_nsa_rd_2013_56002v1.pdf

Graph is an Emerging Market Popularity based on Social Media mentions and sentiment analysis Graph Database Popularity Property Graph increased 250% RDF stores are tied at #3 with: Document stores Key value stores Native XML stores Source: DB-Engines.com, 2014 13

Graph Analysis Represent your data as a graph, analyze it and discover useful information By considering relationships between data entities Recommendation customer items Influencer Identification Pattern Matching P1 ex P2 friend friend friend P3 P4 Purchase Record Communication Stream (e.g. tweets) Create recommendations for a specific customer from its neighbors in a purchase graph Identify nodes that are critical to connectivity of an information flow graph Find sub-graphs that match a specified pattern 14

Typical Graph Problems & Applications Data Integration Pattern matching Link analysis Recommender system Expert/Influencer Identification Clustering/Community Discovery Network bottleneck 15

Graph Analytics Workflow Basic flow Represent raw data as graphs using a graph data model (RDF or Property Graph) Run analysis algorithms on the graphs Exploration phase Data scientists try different ideas (algorithms) on the data Flexible, interactive, iterative, small-scale (sampled),. Production phase Important discoveries are applied to the production system Fixed, automated, batch-oriented, large-scale, Production System Ideas about the data Data Entities Graph Representation Run Graph Analysis Discoveries on the data 16

Oracle Spatial and Graph 17

Oracle Spatial and Graph In-Database Datatypes, Models and Analytics Complete Open Integrated Most Widely Used 18

Oracle Spatial and Graph Mature, Proven Graph Database Capabilities Graph Features Network Data Model graph W3C RDF Semantic graph 19

Network Data Model Graph Use Cases Transportation, Road and Multimodal Networks Drive Time Polygon Analysis Trade Area Management Oracle Spatial and Graph Service Delivery Optimization Water, Gas, Electric Utility, Network Applications 20

Network Data Model Graph Features A storage model to represent graphs and networks Graph tables consist of links and nodes Explicitly stores and maintains connectivity of the network graph Attributes at link and node level Logical or spatial graphs Can logically partition the network graph Java API to perform Analysis in memory Loads and retains only the partitions needed Dynamic costs with real time input Shortest path, within cost, nearest neighbors Traveling salesman, spanning tree,... Multiple Cost Support in Path/Subpath Analysis 21

Real World Feature Modeling in NDM Graph Feature Representation Network Representation 22

Network Data Model Graph Temporal Modeling/Analysis Traffic Patterns Record historical travel Based on time of day and day of the week NDM can use traffic patterns to compute shortest paths Support Nokia/HERE Traffic Patterns format out of the box 10 PM 8 AM 23

Network Data Model Graph Multi-Modal Routing Each mode (car, bus, rail, bike, etc) modeled as a separate network Single logical network represents all modes of transportation Transition nodes where networks meet NDM APIs can specify the modes Out of the box support for transit data published by transit authorities Train & Bus Bus Only - http://www.oracle.com/technetwork/database/options/spatialandgraph/spatial-and-graph-wp-12c-1896143.pdf - http://docs.oracle.com/cd/e16655_01/appdev.121/e17897/toc.htm 24

Network Data Model Graph Large Scale Drive Time/Distance Analysis Big Data Analysis Millions of customers, find closest store within a specified drive time Single database query to find closest store and drive time/distance for each customer Customers geocode as based on graph segment Network Buffer generates all possible paths Store Location Customer Location 25

W3C RDF Semantic Graph 26

Semantic Technology Stack Core Technologies URI RDF RDFS OWL Uniform resource identifier Resource description framework RDF Schema Web ontology language 27 http://www.w3.org/2007/03/layercake.svg

What is RDF A graph data model for web resources and their relationships The graph can be serialized into - RDF/XML, N3, N-TRIPLE, http://www.foobar.com http:// /locatedin CA http:// /produce Construction unit: Triple (or assertion, or fact) <http://foobar> <:produces> <:mp3> Subject Predicate Object Quads (named graphs) add context, provenance, identification, etc. to assertions <http://foobar> <:produces> <:mp3 > <:ProductGraph> http://www.foobar.com/products/mp3 http:// /customerof http:// /uses http://www.oracle.com http:// /produce http://www.oracle.com/products/rdf 28

Basic Elements of RDF Instances E.g. :John, :MovieXYZ, :PurchaseOrder432 Classes Class represents a group/category/categorization of instances E.g. :John rdf:type :Student Properties Linking data together E.g. :John :brother :Mary, :John :hasage 33 ^^xsd:integer. 29

A Small RDF Graph Linking Several Data Sources 30

Many Known Graphs and Vocabularies on the Web DBPedia SIOC NCI SNOMED FOAF Geonames CIA World Fact Book DBLP UniProt UniParc CiteSeer Wordnet Drug Bank ACM Daily Med Linked CT Eurostat KEGG Data.gov.uk Music Brainz Data Semantic Tweet CO2 Emission And so much more! Semanitc XBRL US Census YAGO Cyc/Open Cyc PubMed Freebase Gene Ontology UniRef Smart Link Reactome Diseasome 31

RDF Graph Can Enrich Your Business Applications Flexible graph modeling adds agility Resource identification adds precision Integrate full breadth of enterprise content (structured, spatial, email, documents, web services) Reconcile differences in data semantics so that they can all talk and interoperate; Resolve semantic discrepancies across databases, applications Create consolidated single views across business applications Model and implement common Business Processes 32

Oracle Spatial and Graph: Enterprise Graph Capability RDF Semantic Graph works well with these great technologies Relational, XML, Spatial, Text, Security, Clustering, Compression, Data Guard Oracle s RDF/OWL support is native to the Database Web Services, SOA, BPMN, Support of popular Java APIs and standard complaint Web Service endpoint Advanced Analytics Support integration with OBIEE, Oracle Data Mining, Oracle R Enterprise A rich set of third party tools including Ontology editing, knowledge management, Complete DL reasoners Graph/network visualization NLP, text processing 33

RDF Semantic Graph Use Cases Linked Data & Public Clouds Text Mining & Entity Analytics Social Media Analysis Unified content metadata model for public clouds Validate semantic and structural consistency Find related content & relations by navigating connected entities Reason across entities Analyze content using integrated metadata - Blogs, wikis, video - Calendars, IM, voice 34

Oracle Spatial and Graph RDF Triple Store Leverages Oracle Manageability: RAC & Exadata scalability Compression & partitioning SQL*Loader direct path load Parallel load, inference, query High Availability Triple-level label security Ladder based inference Choice of SPARQL, SQL, or Java Native inference engine Enterprise Manager Load / Storage Query Reasoning Analytics Native RDF graph data store Manages billions of triples Optimized storage architecture SPARQL-Jena/Joseki, Sesame SQL/graph query, B-tree indexing Ontology assisted SQL query RDFS, OWL2 RL, EL, SKOS User-defined rules Incremental, parallel reasoning User-defined inferencing Plug-in architecture Semantic indexing framework Integration with OBIEE, Oracle R Enterprise Oracle Data Mining 35

New functions in Oracle Spatial and Graph Open Geospatial Consortium (OGC) GeoSPARQL Native SPARQL 1.1 query support 40+ new query functions/operators: IF, COALESCE, STRBEFORE, REPLACE, ABS, Aggregates: COUNT, SUM, MIN, MAX, AVG, GROUP_CONCAT, SAMPLE Subqueries Value Assignment: BIND, GROUP BY Expressions, SELECT Expressions Negation: NOT EXISTS, MINUS Improved Path Searching with Property Paths 36

New functions in Oracle Spatial and Graph RDF views on relational tables (through RDB2RDF) RDF views can be created on a set of relational tables and/or views SPARQL queries access data from both a relational and RDF store Support RDF view creation using Direct Mapping: simple and straightforward to use R2RML Mapping: customizations allowed Inference Native OWL 2 EL inference support User defined inferencing Ladder Based Inference Performance optimization for user defined rules Integration with TrOWL, an external OWL 2 reasoner 37 * http://trowl.eu/

Jena Adapter for Oracle Database Requires Apache Jena 2.7.2, ARQ 2.9.2, Joseki 3.4.4, Oracle 11.2.0.3 or higher SPARQL 1.1 compliance Named Graph (quads) support: DatasetGraphOracleSem N-QUADS, TriG data format Updated StatusListener interface Named graph queries through Joseki web service endpoint SPARQL Update through Joseki web service endpoint JSON output Named graph based local inference: Attachment 38

Jena Adapter for Oracle Database (2) Analytical functions for RDF data: SemNetworkAnalyst Integrating Oracle Spatial and Graph network data model (NDM) with RDF Semantic Graph feature Provides functions including shortest path, within cost, partitioning, Extensible architecture 39

Tools, Tools, & Tools! Ontology editing Visualization Business Intelligence R Data Mining Knowledge management 40

Industries Have Already Adopted the Concept Industries Life Sciences Finance Media Networks & Communications Defense & Intelligence Public Sector Hutchinson 3G Austria 41

How Things Work Under the Cover? 42

SPARQL Query Processing HTTP Standard SPARQL Endpoint Enhanced with query management control Java Jena API Jena Adapter Sesame API Sesame Adapter SQL SEM_MATCH SPARQL-to-SQL Core Logic 43

Native Parallel Inference Engine in Oracle Parallel Execution Logical inference can discover hidden relationships with rules?x :hasparent?y.?y :hasbrother?z?x :hasuncle?z?x :relatedto?y.?y :relatedto?z?x :relatedto?z family:john :hasparent family:mary family:jack :hasbrother Implementing an Inference Engine for RDFS/OWL Constructs, ICDE 2008 Optimizing Enterprise-scale OWL 2 RL Reasoning in a Relational Database System, ISWC 2010 Advancing the Enterprise-class OWL Inference Engine in Oracle Database, ORE 2012 Making the Most of your Triple Store: Query Answering in OWL 2 Using an RL Reasoner, WWW 2013 ns:jill :relatedto :relatedto ns:jedi 44

Native Parallel Inference Engine in Oracle (2) Parallel Execution Logical inference can discover hidden relationships with rules?x :hasparent?y.?y :hasbrother?z?x :hasuncle?y?x :relatedto?y.?y :relatedto?z?x :relatedto?z family:john :hasparent :hasuncle family:jack family:mary :hasbrother Graph becomes more connected! ns:jill :relatedto :relatedto ns:jedi 45

Using RDB2RDF (R2RML): Overall Flow Query Writer SPARQL QUERY Schema: Classes and Predicates Map: Classes and Predicates DB Objects SPARQL to SQL Translator R2RML Document R2RML Processor R2RML Map Author Source Relational Database 46

Performance 47

Setup for Performance Use a balanced hardware system for databases and mid-tier servers A single, huge physical disk for everything is not recommended. Multiple hard disks tied together through ASM is a good practice A virtual machine for multiple databases and applications is not recommended Make sure throughput of hardware components matches up Component Hardware spec Sustained throughput CPU core - 100-200 MB/s 1/2 Gbit HBA 1/2 Gbit/s 100/200 MB/s 16 port switch 8 * 2 Gbit/s 1,200 MB/s Fiber channel 2 Gbit/s 200 MB/s Disk controller 2 Gbit/s 200 MB/s GigE NIC (interconnect) 2 Gbit/s 80 MB/s* Disk (spindle) 30-50 MB/s MEM 2k-7k MB/s 48

Configure OS and Network Network configuration is important to data integration performance Network MTU (TCP, Infiniband) net core rmem_max, wmem_max Linux OS Kernel parameters shmmax, shmall, aio-max-nr, sem, 49

Configure Database Database parameters SGA, PGA, filesystemio_options, db_cache_size, auto dop, Calibrate I/O performance DBMS_RESOURCE_MANAGER.CALIBRATE_IO Gather statistics Run a typical workload on a typical data set Check AWR report to see top waits Check SQL Monitor report to find bottlenecks in SQL executions 50

Configure Mid-Tier Server Understand bottleneck Use tools, jstack/top for example, to identify top threads Set a proper JVM heap size Pay close attention to GC activities and memory related settings Try XX:+UseParallelGC, -XX:+UseConcMarkSweepGC, :NewRatio, :SurvivorRatio, etc. For Java clients using JDBC (through Jena Adapter) Network MTU, Oracle SQL*Net parameters including SDU, TDU, SEND_BUF_SIZE, RECV_BUF_SIZE, Linux Kernel parameters: net.core.rmem_max, wmem_max, net.ipv4.tcp_rmem, tcp_wmem, 51

Oracle Spatial and Graph - LUBM 200K on 3-Node RAC Sun Server X2-4 Load, Inference and Query Performance The LUBM 200K Graph has 48+ Billion triples (edges) Original graph has 26.6 Billion unique triples (quads) Inference produced another 21.4 Billion triples Data Loading Performance Triples Loaded and Indexed Per Second (TLIPS): 273K Inference Performance Triples Inferred and Indexed Per Second (TIIPS): 327K SPARQL Query Performance Query Results Per Second (QRPS): 459K Setup: Hardware: Sun Server X2-4, 3-node RAC - Each node configured with 1TB RAM, 4 CPU 2.4GHz 10-Core Intel E7-4870) - Storage: Dual Node 7420, both heads configured as: Sun ZFS Storage 7420 4 CPU 2.00GHz 8-Core (Intel E7-4820) 256G Memory 4x SSD SATA2 512G (READZ) 2x SATA 500G 10K. Four disk trays with 20 x 900GB disks @10Krpm, 4x SSD 73GB (WRITEZ) Software: Oracle Database 11.2.0.3.0, SGA_TARGET=750G and PGA_AGGREGATE_TARGET=200G Note: Only one node in this RAC was used for performance test. Test performed in April 2013. 52

Oracle Enterprise Manager Understand exactly what is the going on Configuration Storage Security Performance Real time monitor CPU Memory I/O Sessions Activity Workload 53

Oracle Enterprise Manager Understand exactly what is the going on Configuration Storage Security Performance Real time monitor CPU Memory I/O Sessions Activity Workload 54

Summary of New Graph Features Network Data Model graph Real World Feature Modeling Multimodal Routing, Temporal Modeling and Analysis Large Scale Drive Time/Distance Analysis RDF Semantic Graph RDF views on relational tables SPARQL 1.1, GeoSPARQL, SPARQL Gateway Enhanced Reasoning and Security Named Graphs Future work on Large-Scale Parallel Graph Analytics Parallel In memory graph analytics, SQL-based graph analytics, Distributed in-memory analytics Integration with Green-Marl 55

56

57