Optimization of Analytic Window Functions

Analytic functions represent the state-of-the-art way of performing complex data analysis within a single SQL statement. In particular, an important class of analytic functions that has been frequently used in commercial systems to support OLAP and decision support applications is the class of window functions. A window function returns for each input tuple a value derived from applying a function over a window of neighboring tuples. However, existing window function evaluation approaches are based on a naive sorting scheme. In this paper, we study the problem of optimizing the evaluation of window functions. We propose several efficient techniques, and identify optimization opportunities that allow us to optimize the evaluation of a set of window functions. We have integrated our scheme into PostgreSQL. Our comprehensive experimental study on the TPC-DS datasets as well as synthetic datasets and queries demonstrate significant speedup over existing approaches.Comment: VLDB201

Multi-community command and control systems in law enforcement: An introductory planning guide

A set of planning guidelines for multi-community command and control systems in law enforcement is presented. Essential characteristics and applications of these systems are outlined. Requirements analysis, system concept design, implementation planning, and performance and cost modeling are described and demonstrated with numerous examples. Program management techniques and joint powers agreements for multicommunity programs are discussed in detail. A description of a typical multi-community computer-aided dispatch system is appended

Concurrent Receipt of Social Security Disability Insurance (SSDI) and Unemployment Insurance (UI): Background and Legislative Proposals

[Excerpt] Although Social Security Disability Insurance (SSDI) and Unemployment Insurance (UI) both provide income support to eligible individuals, the two programs serve largely separate populations. SSDI provides long-term benefits to statutorily disabled individuals who worked in jobs covered by Social Security and to their eligible dependents. In contrast, UI provides temporary benefits to involuntarily unemployed workers who meet the requirements of state law. Under certain circumstances, however, individuals are eligible for both programs. Several proposals have been introduced in the 114th Congress to prevent or reduce concurrent receipt of SSDI and UI benefits. Proponents of these bills contend that concurrent receipt is “double dipping” or duplicative, inasmuch as each payment serves the same function of replacing lost earnings. Opponents argue that concurrent receipt of SSDI and UI benefits is consistent and appropriate under law, because the SSDI program actively encourages beneficiaries to return to work through various work incentives. This report provides background on SSDI and UI and explains how individuals may be eligible for both programs concurrently. It also summarizes the competing arguments for and against concurrent eligibility and examines the legislative proposals introduced in the 114th Congress to deny or offset the SSDI benefits of individuals in receipt of UI. The report ends with a discussion of potential issues in implementing such proposals. of potential issues in implementing such proposals

Philanthropic Engagement with Community Youth Violence Prevention Initiatives

Around the country, many communities are employing a new approach to prevent youth violence. Pulling together leaders across disciplines, shaped by local champions of change, communities are engaging in innovative and data-driven multidisciplinary efforts that engage all key community entities in order to stem the tide of youth violence and restore hope and opportunity so that every child in their midst can be safe in backyards and schoolyards, sidewalks and hallways on every street and neighborhood. Some of these comprehensive community-wide efforts have been seeded by federal initiatives including the Promise and Choice Neighborhood initiatives, Safe Streets, Strong Communities, Defending Childhood and the National Forum on Youth Violence Prevention. This paper will highlight the work of the National Forum and opportunities for philanthropic engagement with this work

BlockTag: Design and applications of a tagging system for blockchain analysis

Annotating blockchains with auxiliary data is useful for many applications. For example, e-crime investigations of illegal Tor hidden services, such as Silk Road, often involve linking Bitcoin addresses, from which money is sent or received, to user accounts and related online activities. We present BlockTag, an open-source tagging system for blockchains that facilitates such tasks. We describe BlockTag's design and present three analyses that illustrate its capabilities in the context of privacy research and law enforcement