Title and Author of Paper Access Path Selection in a Relational Database Management System. P. G. Selinger et al. Summary This paper describes methods of the SQL query optimizer for determining the cost of satisfying a query. It also describes methods for choosing among several competing methods. What are the motivations for this work? SQL is a high-level language where requests for data are stated non-procedurally. The user is not expected to need any knowledge of how the data is stored in the database or how it is retrieved. Thus, it is up to the DBMS to choose an appropriate access path for data retrieval on the users behalf. By designing the database in this fashion, we preserve data independence, where a users view of the data is independent of the databases view of the data. ...

Title and Author of Paper Eddies: Continuously Adaptive Query Processing. Ron Avnur and Joseph M. Hellerstein. Summary Eddies describes a query optimization system that continuously reorders operators in a query plan as the it runs. This insight is based on the observation that assumptions made about the database at the time that a query is submitted will rarely hold throughout the duration of query processing. Query plans can be reordered using two criteria: synchronization barriers and moments of symmetry. Synchronization barriers exist whenever an operator is waiting for a table scan to complete before making forward progress. In general, these barriers limit concurrency and one goal of the eddies system is to avoid or improve these barriers by selecting an appropriate join algorithm. ...

Title and Author of Paper The Gamma Database Machine Project. David J. DeWitt et al. Summary This paper presents the research undertaken at the University of Wisconsin-Madison to develop a scalable database architecture. The paper presents novel methods for scaling a database cluster using a shared-nothing architecture, and for using hash-based join algorithms to parallelize the workload across the cluster. What are the motivations for this work? The motivation behind Gamma was to support horizontally scalable database using commodity parts. ...

I’ve been working on an application to read data from a Kinesis using the Kinesis Client Library for Java. One requirement was to be able to run the application locally during development. This requires configuring Kinesis, DynamoDB, and CloudWatch to work locally. Dynalite Getting a local copy of DynamoDB running is easily done using the dynalite library. > npm install -g dynalite > dynalite --port 7000 Kinesalite A local copy of Kinesis is found with the kinesalite library. ...

Title and Author of Paper The Design of POSTGRES, Michael Stonebraker and Lawrence A. Rowe. Summary Postgres started as a research project to extend the standard database architecture to support several additional concepts: complex objects as values, user-defined data types and procedures, and alerting and triggers. This paper describes the system architecture designed to achieve these goals, while retaining functionality of the relational model. Although the design incorporates additional ideas such as time varying data, I will focus my review on the user-defined types and alerting scenarios. ...

Title and Author of Paper System R: Relational Approach to Database Management. M. M. Astrahan et al. Summary It’s hard to overstate the influence that the System R project had on database design and implementation. After reading this paper it is clear that traditional database architecture has not significantly changed since the System R project. System R provided the first implementation of SQL, the first demonstration of performant transactions, and provided the foundational groundwork in concurrency control and query optimization. ...

Imagine a fledgling software startup consisting of one or two developers. They are following the lean startup methodology by throwing ideas and implementations at a wall to see what sticks. This methodology demands keeping your application as simple as possible until you find the optimum market. An on-going concern for the developers is finding a simple, flexible way to store application data: NoSQL or SQL? The NoSQL database offers a premium out-of-the-box experience: install a package, start the database, and post and retrieve data using a JSON API. And by eschewing the details of a schema and the inconvenience of data modelling, the NoSQL database allows for fast iteration. ...

Title and Author of Paper Architecture of a Database System. Joseph M. Hellerstein, Michael Stonebraker, James Hamilton. Summary Architecture of a Database System provides an explanation of how to implement a relational database. It begins with an architectural overview of the main parts of a database system as viewed through the life of an SQL query. This includes how the query is received, parsed and optimized and how the resulting data is returned from storage as part of a transaction. ...

Have you come across the misfortune of needing to auto-generate Java source code? Luckily, anything you’ve wanted to do with Java has already been done — and auto-generating Java is no different. I recently used JCodeModel to translate from JSON to Java — it worked great but it lacks any tutorial-style documentation. This article means to fill that gap. If you feel the need to go more in-depth, consult the the Javadoc. ...

This article describes how you can use the Dataflow/Beam SDK to write files to an S3 bucket by implementing a Sink. A Sink has three phases: initialization, writing, and finalization. The initialization phase is a sequential process where you can create necessary preconditions such as output directories. The write phase lets workers write bundles of records to the Sink. The finalization phase allows for cleanup like merging files or committing writes. ...