Benvenuti nel Mondo della Oberliga Bremen: La Serie che Non Puoi Perdere!
    La Oberliga Bremen è la competizione calcistica che sta riscuotendo sempre più interesse tra gli appassionati del calcio tedesco. Questa lega, che si colloca al sesto livello del sistema calcistico tedesco, rappresenta un terreno fertile per scoprire talenti emergenti e godersi partite avvincenti. Grazie a questa guida, potrai rimanere aggiornato con le ultime partite e ricevere le previsioni di esperti sulle scommesse sportive, per non perdere mai un colpo in questo entusiasmante campionato.
    
    Le Squadre da Tenere d'Occhio
    In Oberliga Bremen, ogni partita è un'opportunità per assistere a sorprese e capovolgimenti di fronte. Ecco alcune delle squadre che stanno attirando l'attenzione per la loro prestazione eccezionale:
    
        - Bremer SV: Conosciuto per il suo gioco dinamico e le strategie innovative, il Bremer SV continua a stupire i suoi tifosi con prestazioni costanti.
- SC Weyhe: Questa squadra ha dimostrato grande resilienza e determinazione, rendendola una delle favorite per la promozione.
- TuS Schwachhausen: Con una solida difesa e un attacco veloce, il TuS Schwachhausen è sempre pronto a sfidare i favoriti del campionato.
Gli Highlights delle Partite di Oggi
    Ogni giorno offre nuove emozioni e momenti indimenticabili. Ecco alcuni degli highlights delle partite di oggi che non ti devi assolutamente perdere:
    
        - Bremer SV vs SC Weyhe: Una sfida cruciale per la classifica. Entrambe le squadre sono in forma smagliante e questa partita promette di essere un vero spettacolo.
- TuS Schwachhausen vs VfB Oldenburg: Una partita che mette in palio punti preziosi per la lotta ai vertici del campionato.
Previsioni di Esperti sulle Scommesse Sportive
    Per gli appassionati di scommesse sportive, la Oberliga Bremen offre numerose opportunità per fare pronostici accurati. Ecco alcune delle previsioni di esperti che potrebbero aiutarti a vincere:
    
        - Pronostico Bremer SV vs SC Weyhe: Vittoria Bremer SV con un risultato finale di 2-1. Le statistiche recenti indicano una maggiore solidità difensiva da parte del Bremer SV.
- Pronostico TuS Schwachhausen vs VfB Oldenburg: Pareggio con un risultato finale di 1-1. Entrambe le squadre hanno dimostrato di poter mantenere una buona organizzazione difensiva.
L'Atmosfera nei Campi: Un Viaggio Emozionale
    Ogni partita della Oberliga Bremen è accompagnata da un'atmosfera unica, creata dai tifosi accesi che sostengono le loro squadre con passione. Il tifo locale è uno degli aspetti più affascinanti di queste gare, rendendo ogni incontro una vera festa del calcio.
    I Migliori Momenti delle Partite: Gol Spettacolari e Giocate Memorabili
    Gol spettacolari e giocate memorabili sono all'ordine del giorno in Oberliga Bremen. Ecco alcuni dei momenti più belli delle ultime partite:
    
        - Gol da Incorniciare: Un tiro magistrale da fuori area ha lasciato tutti senza fiato durante la partita tra Bremer SV e SC Weyhe.
- Parata Strepitosa: Il portiere del TuS Schwachhausen ha effettuato una parata incredibile, salvando la porta su un tiro a giro dal limite dell'area.
L'Impatto Sociale del Calcio nella Comunità
    Oltre al puro divertimento sportivo, il calcio in Oberliga Bremen ha un impatto significativo sulla comunità locale. Le squadre sono spesso coinvolte in iniziative sociali, promuovendo valori come il fair play e l'integrazione sociale attraverso il calcio.
    Tecniche di Gioco e Strategie delle Squadre
    Ogni squadra della Oberliga Bremen ha le sue peculiarità tecniche e strategiche. Ecco alcune delle tattiche più interessanti adottate dalle squadre:
    
        - Bremer SV: Predilige un gioco offensivo con rapidi contropiedi, sfruttando la velocità dei suoi esterni.
- TuS Schwachhausen: Mette l'accento su una difesa compatta e organizzata, cercando di ripartire in contropiede.
L'Evoluzione della Oberliga Bremen nel Tempo
    Nel corso degli anni, la Oberliga Bremen ha visto numerosi cambiamenti sia in termini di strutture organizzative che di qualità del gioco. Questo campionato continua a crescere, attirando sempre più giovani talenti desiderosi di farsi strada nel mondo del calcio professionistico.
    Futuro della Oberliga Bremen: Prospettive e Sviluppi
    Il futuro della Oberliga Bremen sembra promettente, con progetti in corso per migliorare le infrastrutture dei campi e aumentare l'interesse mediatico. Queste iniziative mirano a consolidare ulteriormente il ruolo della lega nel panorama calcistico tedesco.
    Risorse Online per Seguire la Oberliga Bremen
    Ecco alcune risorse online dove puoi rimanere aggiornato su tutte le novità della Oberliga Bremen:
    
    Predizioni Esperte: Come Prevedere i Risultati delle Partite?
<|repo_name|>thomas-kratz/thesis<|file_sep|>/chapters/related.tex
chapter{Related Work}
label{chapter:related}
The advent of big data technologies and the need to process large amounts of data quickly has led to the development of many new approaches for distributed data processing.
In this chapter we introduce the most prominent distributed data processing frameworks and explain their concepts and limitations.
Furthermore we give an overview over different approaches for executing database queries on big data systems.
We then introduce the most relevant systems for executing graph algorithms on big data systems.
Finally we introduce MapReduce and Spark as two popular frameworks for executing tasks on big data.
section{Distributed Data Processing}
label{sec:distributed_data_processing}
In this section we give an overview over existing distributed data processing frameworks and explain their concepts and limitations.
subsection{Hadoop}
Apache Hadoop cite{apache:hadoop} is one of the most prominent distributed data processing frameworks and is based on the Google MapReduce paper cite{dean2008mapreduce}.
It is designed to process large amounts of data by using a cluster of commodity hardware machines.
Hadoop provides several services that are important for distributed computing such as resource management and failure recovery.
The main components of Hadoop are the Hadoop Distributed File System (HDFS) cite{shvachko2010overview} and MapReduce.
HDFS is a scalable distributed file system that is designed to store large amounts of data on commodity hardware.
HDFS splits files into blocks which are stored across multiple machines.
The size of the blocks can be configured by the user but defaults to 64 MB.
Each block has three replicas that are stored on different machines to provide fault tolerance.
HDFS provides several optimizations to ensure high throughput when reading or writing files.
MapReduce is an abstraction that simplifies parallel programming for big data processing.
It consists of two steps: The map step takes a set of key/value pairs as input and produces another set of key/value pairs as output.
The reduce step merges all values belonging to one key cite{dean2008mapreduce}.
MapReduce can be extended with additional steps such as combining cite{jarvinen2011optimizing} or partitioning cite{jarvinen2011optimizing} steps.
MapReduce is a batch processing framework that was developed for processing large amounts of data that does not require low latency.
As it was designed for batch processing it is not suitable for interactive queries where low latency is required.
subsection{Spark}
Apache Spark cite{zaharia2010spark} is a fast and general-purpose cluster computing framework that provides APIs in Java, Scala and Python.
Spark supports several programming models such as MapReduce cite{zaharia2010spark}, SQL queries cite{meng2015spark}, streaming applications cite{meng2015spark} or machine learning applications cite{meng2015spark}.
Spark provides a number of advantages over Hadoop MapReduce:
First it supports more than just the map/reduce paradigm by providing APIs for SQL queries or machine learning applications.
Second it provides a more flexible execution model that enables developers to combine different types of computations which would otherwise require multiple jobs in MapReduce.
Third it executes jobs faster than Hadoop by performing computations in memory instead of writing intermediate results to disk after each step like MapReduce does.
Spark's performance advantage over MapReduce comes at the cost of reduced fault tolerance compared to Hadoop.
While Hadoop can recover from failures by re-executing failed jobs from scratch Spark can only recover from failures within individual jobs by recomputing lost partitions based on lineage information stored in memory or disk.
subsection{Pregel}
Pregel cite{malewicz2010pregel} is a distributed graph computation framework developed at Google for running iterative graph algorithms on very large graphs efficiently.
Pregel uses vertex-centric programming which means that developers define computations for each vertex individually without having to define global operations over all vertices or edges like many other graph computation frameworks do.
Pregel consists of three main components: The computation engine which executes the graph computations, the master which manages vertices during computation and coordinates workers and the workers which execute computations for vertices assigned to them.
To enable efficient parallelization Pregel uses vertex-centric programming where each vertex executes its own computation independently from other vertices without requiring synchronization with them.
Pregel's main disadvantage compared to other graph computation frameworks such as Giraph or GraphLab is its limited support for complex algorithms due to its simple vertex-centric programming model.
subsection{GraphX}
GraphX cite{xiao2013graphx} is an extension of Apache Spark that adds support for graph processing to Spark's existing capabilities such as batch processing or machine learning applications.
GraphX provides several APIs for working with graphs including GraphFrames which allows users to work with graphs using DataFrame operations similar to how they would work with relational tables in SQL databases.
GraphX supports various types of graph computations including PageRank cite{xiao2013graphx}, connected components cite{xiao2013graphx}, triangle counting cite{xiao2013graphx}, shortest paths cite{xiao2013graphx}, centrality measures cite{xiao2013graphx}, etc.
GraphX provides several advantages over other graph processing frameworks such as Pregel:
First it leverages Spark's fast execution model which allows users to execute graph computations much faster than they could with Pregel alone.
Second it provides higher-level abstractions for working with graphs compared to Pregel's low-level vertex-centric programming model which makes it easier for users who are not familiar with graph theory concepts like degree distribution or clustering coefficient etc..
subsection{Summary}
We have introduced several distributed data processing frameworks and explained their concepts and limitations:
Hadoop provides high-throughput batch processing but lacks support for interactive queries due its high latency compared to other frameworks like Spark or GraphX.
Spark provides faster execution times than Hadoop by performing computations in memory instead of writing intermediate results to disk after each step like MapReduce does however it has reduced fault tolerance compared to Hadoop since it can only recover from failures within individual jobs while Hadoop can recover from failures by re-executing failed jobs from scratch .
Pregel provides simple vertex-centric programming model which makes it easy for developers who are not familiar with graph theory concepts however this simplicity comes at cost since Pregels limited support makes it difficult if not impossible implement complex algorithms like PageRank .
GraphX builds upon Spark's fast execution model while adding higher-level abstractions than Pregels low-level vertex-centric programming model making it easier use even if you're not familiar with graphs .
section{Executing Database Queries on Big Data Systems}
label{sec:executing_db_queries_on_big_data_systems}
In this section we give an overview over different approaches for executing database queries on big data systems.
subsection{NoSQL Databases}
NoSQL databases are designed to store large amounts of semi-structured or unstructured data across multiple servers without requiring expensive hardware resources like traditional RDBMSs do cite{kumar2014survey}.
They provide flexible schemaless models which allow developers store different types values under same column name making them ideal choice when dealing with heterogeneous datasets such as web logs or social media posts etc..
Some popular NoSQL databases include MongoDB cite{kumar2014survey}, Cassandra cite{kumar2014survey}, Couchbase cite{kumar2014survey} etc..
NoSQL databases provide several advantages over traditional RDBMSs when dealing with big datasets:
First they provide flexible schemaless models allowing developers store different types values under same column name making them ideal choice when dealing with heterogeneous datasets such as web logs or social media posts etc..
Second they scale horizontally meaning adding more servers increases storage capacity without requiring expensive hardware upgrades unlike traditional RDBMSs .
Third they provide built-in replication mechanisms ensuring high availability even if some servers fail during operation .
However NoSQL databases also have some disadvantages compared RDBMSs :
First lack ACID transactions support making them unsuitable applications requiring strong consistency guarantees such financial transactions etc..
Second limited query capabilities compared RDBMSs since most NoSQL databases only support simple CRUD operations while supporting complex queries requires additional tools such as Elasticsearch cite{kumar2014survey} .
subsection{NewSQL Databases}
NewSQL databases aim bridge gap between NoSQL databases flexibility scalability RDBMSs ACID transaction support strong consistency guarantees .
They provide horizontal scalability similar NoSQL databases while supporting full SQL query language enabling developers perform complex queries efficiently .
Some popular NewSQL databases include Google Spanner cite{kumar2014survey}, CockroachDB cite:kumar2014survey), VoltDB (kumar 20
14 survey) etc .
NewSQL databases provide several advantages over both NoSQL databases RDBMSs :
First they offer horizontal scalability allowing adding more servers increases storage capacity without requiring expensive hardware upgrades .
Second they support full SQL query language enabling developers perform complex queries efficiently .
Third they provide ACID transactions support ensuring strong consistency guarantees applications requiring high reliability such financial transactions etc .
However NewSQL databases also have some disadvantages compared NoSQL databases RDBMSs :
First limited adoption since most organizations still rely traditional RDBMSs handle their critical workloads .
Second higher operational complexity due need manage multiple servers ensure high availability even if some servers fail during operation .
subsection{Summary}
We have introduced different approaches executing database queries big data systems including NoSQL databases NewSQL databases :
NoSQL databases provide flexible schemaless models allowing developers store different types values under same column name making them ideal choice when dealing heterogeneous datasets however lack ACID transactions support making unsuitable applications requiring strong consistency guarantees .
NewSQL databases aim bridge gap between NoSQL flexibility scalability RDBMSs ACID transaction support strong consistency guarantees offering horizontal scalability full SQL query language however have limited adoption higher operational complexity due need manage multiple servers ensure high availability .
section{Executing Graph Algorithms on Big Data Systems}
label{sec:executing_graph_algorithms_on_big_data_systems}
In this section we give an overview over different approaches for executing graph algorithms on big data systems.
subsection{Graph Processing Frameworks}
Graph processing frameworks are designed specifically handle large-scale graphs efficiently providing APIs execute common graph algorithms such PageRank connected components triangle counting etc .
Some popular graph processing frameworks include Apache Giraph (malewicz 20
10), PowerGraph (gupta 20
11), GraphLab (low 20
11) etc .
Graph processing frameworks provide several advantages over general-purpose distributed computing frameworks like Hadoop Spark :
First they provide optimized APIs execute common graph algorithms