Data Warehousing Modernization: Big Data Technology Implementation

Considering the challenges posed by Big Data, the cost to scale traditional data warehouses is high and the performances would be inadequate to meet the growing needs of the volume, variety and velocity of data. The Hadoop ecosystem answers both of the shortcomings. Hadoop has the ability to store and analyze large data sets in parallel on a distributed environment but cannot replace the existing data warehouses and RDBMS systems due to its own limitations explained in this paper. In this paper, I identify the reasons why many enterprises fail and struggle to adapt to Big Data technologies. A brief outline of two different technologies to handle Big Data will be presented in this paper: Using IBM’s Pure Data system for analytics (Netezza) usually used in reporting, and Hadoop with Hive which is used in analytics. Also, this paper covers the Enterprise architecture consisting of Hadoop that successful companies are adapting to analyze, filter, process, and store the data running along a massively parallel processing data warehouse. Despite, having the technology to support and process Big Data, industries are still struggling to meet their goals due to the lack of skilled personnel to study and analyze the data, in short data scientists and data statisticians

Process algebra approach to parallel DBMS performance modelling

Abstract unavailable please refer to PD

Learning a Partitioning Advisor with Deep Reinforcement Learning

Commercial data analytics products such as Microsoft Azure SQL Data Warehouse or Amazon Redshift provide ready-to-use scale-out database solutions for OLAP-style workloads in the cloud. While the provisioning of a database cluster is usually fully automated by cloud providers, customers typically still have to make important design decisions which were traditionally made by the database administrator such as selecting the partitioning schemes. In this paper we introduce a learned partitioning advisor for analytical OLAP-style workloads based on Deep Reinforcement Learning (DRL). The main idea is that a DRL agent learns its decisions based on experience by monitoring the rewards for different workloads and partitioning schemes. We evaluate our learned partitioning advisor in an experimental evaluation with different databases schemata and workloads of varying complexity. In the evaluation, we show that our advisor is not only able to find partitionings that outperform existing approaches for automated partitioning design but that it also can easily adjust to different deployments. This is especially important in cloud setups where customers can easily migrate their cluster to a new set of (virtual) machines

Formal Representation of the SS-DB Benchmark and Experimental Evaluation in EXTASCID

Evaluating the performance of scientific data processing systems is a difficult task considering the plethora of application-specific solutions available in this landscape and the lack of a generally-accepted benchmark. The dual structure of scientific data coupled with the complex nature of processing complicate the evaluation procedure further. SS-DB is the first attempt to define a general benchmark for complex scientific processing over raw and derived data. It fails to draw sufficient attention though because of the ambiguous plain language specification and the extraordinary SciDB results. In this paper, we remedy the shortcomings of the original SS-DB specification by providing a formal representation in terms of ArrayQL algebra operators and ArrayQL/SciQL constructs. These are the first formal representations of the SS-DB benchmark. Starting from the formal representation, we give a reference implementation and present benchmark results in EXTASCID, a novel system for scientific data processing. EXTASCID is complete in providing native support both for array and relational data and extensible in executing any user code inside the system by the means of a configurable metaoperator. These features result in an order of magnitude improvement over SciDB at data loading, extracting derived data, and operations over derived data.Comment: 32 pages, 3 figure

UnifyDR: A Generic Framework for Unifying Data and Replica Placement

The advent of (big) data management applications operating at Cloud scale has led to extensive research on the data placement problem. The key objective of data placement is to obtain a partitioning (possibly allowing for replicas) of a set of data-items into distributed nodes that minimizes the overall network communication cost. Although replication is intrinsic to data placement, it has seldom been studied in combination with the latter. On the contrary, most of the existing solutions treat them as two independent problems, and employ a two-phase approach: (1) data placement, followed by (2) replica placement. We address this by proposing a new paradigm, CDR , with the objective of c ombining d ata and r eplica placement as a single joint optimization problem. Specifically, we study two variants of the CDR problem: (1) CDR-Single , where the objective is to minimize the communication cost alone, and (2) CDR-Multi , which performs a multi-objective optimization to also minimize traffic and storage costs. To unify data and replica placement, we propose a generic framework called UnifyDR , which leverages overlapping correlation clustering to assign a data-item to multiple nodes, thereby facilitating data and replica placement to be performed jointly. We establish the generic nature of UnifyDR by portraying its ability to address the CDR problem in two real-world use-cases, that of join-intensive online analytical processing (OLAP) queries and a location-based online social network (OSN) service. The effectiveness and scalability of UnifyDR are showcased by experiments performed on data generated using the TPC-DS benchmark and a trace of the Gowalla OSN for the OLAP queries and OSN service use-case, respectively. Empirically, the presented approach obtains an improvement of approximately 35% in terms of the evaluated metrics and a speed-up of 8 times in comparison to state-of-the-art techniques.This work was supported by the Agentschap Innoveren & Ondernemen (VLAIO) Strategic Fundamental Research (SBO) under Grant 150038 (DiSSeCt)

The End of a Myth: Distributed Transactions Can Scale

The common wisdom is that distributed transactions do not scale. But what if distributed transactions could be made scalable using the next generation of networks and a redesign of distributed databases? There would be no need for developers anymore to worry about co-partitioning schemes to achieve decent performance. Application development would become easier as data placement would no longer determine how scalable an application is. Hardware provisioning would be simplified as the system administrator can expect a linear scale-out when adding more machines rather than some complex sub-linear function, which is highly application specific. In this paper, we present the design of our novel scalable database system NAM-DB and show that distributed transactions with the very common Snapshot Isolation guarantee can indeed scale using the next generation of RDMA-enabled network technology without any inherent bottlenecks. Our experiments with the TPC-C benchmark show that our system scales linearly to over 6.5 million new-order (14.5 million total) distributed transactions per second on 56 machines.Comment: 12 page

Scaling Up Concurrent Analytical Workloads on Multi-Core Servers

Today, an ever-increasing number of researchers, businesses, and data scientists collect and analyze massive amounts of data in database systems. The database system needs to process the resulting highly concurrent analytical workloads by exploiting modern multi-socket multi-core processor systems with non-uniform memory access (NUMA) architectures and increasing memory sizes. Conventional execution engines, however, are not designed for many cores, and neither scale nor perform efficiently on modern multi-core NUMA architectures. Firstly, their query-centric approach, where each query is optimized and evaluated independently, can result in unnecessary contention for hardware resources due to redundant work found across queries in highly concurrent workloads. Secondly, they are unaware of the non-uniform memory access costs and the underlying hardware topology, incurring unnecessarily expensive memory accesses and bandwidth saturation. In this thesis, we show how these scalability and performance impediments can be solved by exploiting sharing among concurrent queries and incorporating NUMA-aware adaptive task scheduling and data placement strategies in the execution engine. Regarding sharing, we identify and categorize state-of-the-art techniques for sharing data and work across concurrent queries at run-time into two categories: reactive sharing, which shares intermediate results across common query sub-plans, and proactive sharing, which builds a global query plan with shared operators to evaluate queries. We integrate the original research prototypes that introduce reactive and proactive sharing, perform a sensitivity analysis, and show how and when each technique benefits performance. Our most significant finding is that reactive and proactive sharing can be combined to exploit the advantages of both sharing techniques for highly concurrent analytical workloads. Regarding NUMA-awareness, we identify, implement, and compare various combinations of task scheduling and data placement strategies under a diverse set of highly concurrent analytical workloads. We develop a prototype based on a commercial main-memory column-store database system. Our most significant finding is that there is no single strategy for task scheduling and data placement that is best for all workloads. In specific, inter-socket stealing of memory-intensive tasks can hurt overall performance, and unnecessary partitioning of data across sockets involves an overhead. For this reason, we implement algorithms that adapt task scheduling and data placement to the workload at run-time. Our experiments show that both sharing and NUMA-awareness can significantly improve the performance and scalability of highly concurrent analytical workloads on modern multi-core servers. Thus, we argue that sharing and NUMA-awareness are key factors for supporting faster processing of big data analytical applications, fully exploiting the hardware resources of modern multi-core servers, and for more responsive user experience