Durable Transactions Research Articles

APPROACHES TO BUILD AND DEVELOP DATA WAREHOUSES ACCORDING TO THE NOSQL MODEL

Traditional data warehouses support atomic, consistent, isolated, and durable (abbreviated, ACID) transactions. The ACID property of transactions guarantees the correction of concurrent access to a data warehouse. However, as the CAP1theorem explains, this property is always costly in terms of performance. For this reason, traditional data warehousesshow their limits when used in a very demanding context, such as the Cloud. The work presented in this article aims to propose approaches to build and develop data warehouses according to the column-oriented NoSQL model.

A Model of Anticipated Consumption Tax Changes

This paper studies household spending responses to anticipated changes in the consumption tax. To do so, I construct a life-cycle heterogeneous-agent general equilibrium model with durables. The model features a wedge in durable transactions that reflects the actual consumption tax system: households pay the tax when buying the durables but do not receive the tax when selling them. There are three main findings. First, the baseline model reproduces an empirically consistent dynamic pattern of tax elasticity of the taxable spendings. Second, I find that life-cycle is a key component to match the level of tax elasticity of durable spending. Third, the baseline model generates smaller stockpiling of durables based on realistic motive than a model without the wedge. I then use the model for two counter-factual experiments.The first counter-factual experiment finds that the effect of a consumption tax cut is not symmetric to the tax hike. The second counter-factual experiment which compares a one-time tax hike and a multiple-times tax hike shows the multiple-times tax hike scheme generates smaller welfare cost than one-time tax hike.

D ude T x

Emerging non-volatile memory (NVM) offers non-volatility, byte-addressability, and fast access at the same time. It is suggested that programs should access NVM directly through CPU load and store instructions. To guarantee crash consistency, durable transactions are regarded as a common choice of applications for accessing persistent memory data. However, existing durable transaction systems employ either undo logging , which requires a fence for every memory write, or redo logging , which requires intercepting all memory reads within transactions. Both approaches incur significant overhead. This article presents D ude T x , a crash-consistent durable transaction system that avoids the drawbacks of both undo and redo logging. D ude T x uses shadow DRAM to decouple the execution of a durable transaction into three fully asynchronous steps. The advantage is that only minimal fences and no memory read instrumentation are required. This design enables an out-of-the-box concurrency control mechanism, transactional memory or fine-grained locks, to be used as an independent component. The evaluation results show that D ude T x adds durability to a software transactional memory system with only 7.4%--24.6% throughput degradation. Compared to typical existing durable transaction systems, D ude T x provides 1.7× --4.4× higher throughput. Moreover, D ude T x can be implemented with hardware transactional memory or lock-based concurrency control, leading to a further 1.7× and 3.3× speedup, respectively.

Scalable database logging for multicores

Modern databases, guaranteeing atomicity and durability, store transaction logs in a volatile, central log buffer and then flush the log buffer to non-volatile storage by the write-ahead logging principle. Buffering logs in central log store has recently faced a severe multicore scalability problem, and log flushing has been challenged by synchronous I/O delay. We have designed and implemented a fast and scalable logging method, E leda , that can migrate a surge of transaction logs from volatile memory to stable storage without risking durable transaction atomicity. Our efficient implementation of E leda is enabled by a highly concurrent data structure, G rasshopper , that eliminates a multicore scalability problem of centralized logging and enhances system utilization in the presence of synchronous I/O delay. We implemented E leda and plugged it to WiredTiger and Shore-MT by replacing their log managers. Our evaluation showed that E leda -based transaction systems improve performance up to 71 x, thus showing the applicability of E leda.

DudeTM

Emerging non-volatile memory (NVM) offers non-volatility, byte-addressability and fast access at the same time. To make the best use of these properties, it has been shown by empirical evidence that programs should access NVM directly through CPU load and store instructions, so that the overhead of a traditional file system or database can be avoided. Thus, durable transactions become a common choice of applications for accessing persistent memory data in a crash consistent manner. However, existing durable transaction systems employ either undo logging , which requires a fence for every memory write, or redo logging , which requires intercepting all memory reads within transactions. This paper presents DUDETM, a crash-consistent durable transaction system that avoids the drawbacks of both undo logging and redo logging. DUDETM uses shadow DRAM to decouple the execution of a durable transaction into three fully asynchronous steps. The advantage is that only minimal fences and no memory read instrumentation are required. This design also enables an out-of-the-box transactional memory (TM) to be used as an independent component in our system. The evaluation results show that DUDETM adds durability to a TM system with only 7.4 ~ 24.6% throughput degradation. Compared to the existing durable transaction systems, DUDETM provides 1.7times to 4.4times higher throughput. Moreover, DUDETM can be implemented with existing hardware TMs with minor hardware modifications, leading to a further 1.7times speedup.

DudeTM

Emerging non-volatile memory (NVM) offers non-volatility, byte-addressability and fast access at the same time. To make the best use of these properties, it has been shown by empirical evidence that programs should access NVM directly through CPU load and store instructions, so that the overhead of a traditional file system or database can be avoided. Thus, durable transactions become a common choice of applications for accessing persistent memory data in a crash consistent manner. However, existing durable transaction systems employ either undo logging , which requires a fence for every memory write, or redo logging , which requires intercepting all memory reads within transactions. This paper presents DUDETM, a crash-consistent durable transaction system that avoids the drawbacks of both undo logging and redo logging. DUDETM uses shadow DRAM to decouple the execution of a durable transaction into three fully asynchronous steps. The advantage is that only minimal fences and no memory read instrumentation are required. This design also enables an out-of-the-box transactional memory (TM) to be used as an independent component in our system. The evaluation results show that DUDETM adds durability to a TM system with only 7.4 ~ 24.6% throughput degradation. Compared to the existing durable transaction systems, DUDETM provides 1.7times to 4.4times higher throughput. Moreover, DUDETM can be implemented with existing hardware TMs with minor hardware modifications, leading to a further 1.7times speedup.

DudeTM

Emerging non-volatile memory (NVM) offers non-volatility, byte-addressability and fast access at the same time. To make the best use of these properties, it has been shown by empirical evidence that programs should access NVM directly through CPU load and store instructions, so that the overhead of a traditional file system or database can be avoided. Thus, durable transactions become a common choice of applications for accessing persistent memory data in a crash consistent manner. However, existing durable transaction systems employ either undo logging, which requires a fence for every memory write, or redo logging, which requires intercepting all memory reads within transactions.

High-Performance Transactions for Persistent Memories

Emerging non-volatile memory (NVRAM) technologies offer the durability of disk with the byte-addressability of DRAM. These devices will allow software to access persistent data structures directly in NVRAM using processor loads and stores, however, ensuring consistency of persistent data across power failures and crashes is difficult. Atomic, durable transactions are a widely used abstraction to enforce such consistency. Implementing transactions on NVRAM requires the ability to constrain the order of NVRAM writes, for example, to ensure that a transaction's log record is complete before it is marked committed. Since NVRAM write latencies are expected to be high, minimizing these ordering constraints is critical for achieving high performance. Recent work has proposed programming interfaces to express NVRAM write ordering constraints to hardware so that NVRAM writes may be coalesced and reordered while preserving necessary constraints. Unfortunately, a straightforward implementation of transactions under these interfaces imposes unnecessary constraints. We show how to remove these dependencies through a variety of techniques, notably, deferring commit until after locks are released. We present a comprehensive analysis contrasting two transaction designs across three NVRAM programming interfaces, demonstrating up to 2.5x speedup.

High-Performance Transactions for Persistent Memories

Emerging non-volatile memory (NVRAM) technologies offer the durability of disk with the byte-addressability of DRAM. These devices will allow software to access persistent data structures directly in NVRAM using processor loads and stores, however, ensuring consistency of persistent data across power failures and crashes is difficult. Atomic, durable transactions are a widely used abstraction to enforce such consistency. Implementing transactions on NVRAM requires the ability to constrain the order of NVRAM writes, for example, to ensure that a transaction's log record is complete before it is marked committed. Since NVRAM write latencies are expected to be high, minimizing these ordering constraints is critical for achieving high performance. Recent work has proposed programming interfaces to express NVRAM write ordering constraints to hardware so that NVRAM writes may be coalesced and reordered while preserving necessary constraints. Unfortunately, a straightforward implementation of transactions under these interfaces imposes unnecessary constraints. We show how to remove these dependencies through a variety of techniques, notably, deferring commit until after locks are released. We present a comprehensive analysis contrasting two transaction designs across three NVRAM programming interfaces, demonstrating up to 2.5x speedup.

Assortative Matching, Adverse Selection and Durable Goods: Transaction History, Safety Regulation and the Likelihood of Trade in the Business Aircraft Market

In recent years, considerable progress has occurred in modeling durable goods transactions in dynamic settings under asymmetric information. Most notable among these contributions are the works of Hendel and Lizzeri (1999, 2002), Janssen and Roy (2002), and Hendel, Lizzeri and Siniscalchi (2005). I explore registration changes for a sample of business aircraft over the period 1980-1999 to test some of the predictions of these models. The empirical regularities highlighted in this paper support these models. My results are also consistent with the view that high levels of efficiency can obtain even when information asymmetries condition the durable good trading environment.

Organizational Culture and Relationship Skills

While both the strategic management and the network literature recognize the importance of inter-firm relationships for explaining competitive advantage, the question why firms differ in their ability to benefit from these relationships is rarely addressed. This paper aims to begin to fill this gap in the literature. We argue that organizational culture is an important factor influencing the relationship skills of a firm, defined as a firm's ability to manage its ties with other firms, whether these are customers, suppliers, or service providers. We assume relationship skills to be especially relevant for the formation and maintenance of close and durable transaction ties. We test our model on a dataset of 127 Dutch inter-firm relations and find general support. Specifically, we find that firms with organizational cultures characterized by an orientation towards stability and predictability, a positive orientation towards innovation, and not characterized by a strong focus on immediate results, score high on relationship skills. Relationship skills, in turn, are found to have a positive influence on the outcomes of inter-firm relationships in terms of learning, achieving innovations and gaining new contacts, but not in terms of immediate (financial) results.

Mediation’s Impact on Formal Discrimination Complaint Filing

This article examines a natural field experiment in mediation of employment disputes at the United States Postal Service. Theory suggests that early mediation will lead to earlier, more durable settlements and transaction cost savings. Implementation of the mediation program resulted in a significant decrease in the number of formal discrimination complaints. A well designed employment dispute mediation program can resolve disputes at an earlier stage in the administrative process, and thereby reduce the number of formal complaints filed.