Mortality and Morbidity Following Surgery for Primary Malignant Musculoskeletal Tumors in the Pelvis and Limbs: A Retrospective Analysis Using the Japanese Diagnosis Procedure Combination Database

Introduction: Resection of malignant pelvic tumors has long been considered to be associated with higher postoperative mortality and morbidity than resection of malignant limb tumors. We compared the postoperative adverse events of pelvic tumor surgery and limb tumor surgery using a national inpatient database. Methods: We identified patients who underwent surgery for primary musculoskeletal malignant tumors of the pelvis or limbs between July and December in 2007- 2010 using the Japanese Diagnosis Procedure Combination inpatient database. We calculated the risk-adjusted odds ratio for the occurrence of postoperative complications following pelvic tumor surgery with reference to limb tumor surgery using a multivariable logistic regression analysis. Results: Of 3255 eligible patients, 3116 underwent limb tumor surgery and 139 underwent pelvic tumor surgery. In-hospital mortality was 0.6% and 0.7% and postoperative complication rates were 8.2% and 18.7%, respectively. The rate of blood transfusion and duration of anesthesia over 480 min were higher in the pelvic tumor group. Blood transfusion volume and duration of anesthesia were independently associated with worse outcomes, but there was no significant association between tumor location and occurrence of postoperative complications (odds ratio 1.18, 95% confidence interval 0.73 - 1.88, p = 0.502). Conclusions: Blood transfusion volume and duration of anesthesia were significant predictors of outcome. Our data demonstrate that the higher morbidity rate after pelvic tumor resection could result from the larger blood transfusion volume and longer anesthesia duration.

A Storage Optimization Scheme for Blockchain Transaction Databases

As the typical peer-to-peer distributed networks, blockchain systemsrequire each node to copy a complete transaction database, so as to ensure newtransactions can by verified independently. In a blockchain system (e.g., bitcoinsystem), the node does not rely on any central organization, and every node keepsan entire copy of the transaction database. However, this feature determines thatthe size of blockchain transaction database is growing rapidly. Therefore, with thecontinuous system operations, the node memory also needs to be expanded tosupport the system running. Especially in the big data era, the increasing networktraffic will lead to faster transaction growth rate. This paper analyzes blockchaintransaction databases and proposes a storage optimization scheme. The proposedscheme divides blockchain transaction database into cold zone and hot zone usingexpiration recognition method based on Least Recently Used (LRU) algorithm. Itcan achieve storage optimization by moving unspent transaction outputs outsidethe in-memory transaction databases. We present the theoretical analysis on theoptimization method to validate the effectiveness. Extensive experiments showour proposed method outperforms the current mechanism for the blockchaintransaction databases.

A Surfing Concurrence Transaction Model for Key-Value NoSQL Databases

As more and more application systems related to big data were developed, NoSQL (Not Only SQL) database systems are becoming more and more popular. In order to add transaction features for some NoSQL database systems, many scholars have tried different techniques. Unfortunately, there is a lack of research on Redis’s transaction in the existing literatures. This paper proposes a transaction model for key-value NoSQL databases including Redis to make possible allowing users to access data in the ACID (Atomicity, Consistency, Isolation and Durability) way, and this model is vividly called the surfing concurrence transaction model. The architecture, important features and implementation principle are described in detail. The key algorithms also were given in the form of pseudo program code, and the performance also was evaluated. With the proposed model, the transactions of Key-Value NoSQL databases can be performed in a lock free and MVCC (Multi-Version Concurrency Control) free manner. This is the result of further research on the related topic, which fills the gap ignored by relevant scholars in this field to make a little contribution to the further development of NoSQL technology.

Nested Transaction Concurrency Control in Parallel Real-Time Dat-abases

An integrated method for concurrency control in parallel real-time databases has been proposed in this paper. The nested transaction model has been investigated to offer more atomic execution units and finer grained control within in a transaction. Based on the classical nested locking protocol and the speculative concurrency control approach, a two-shadow adaptive concurrency control protocol, which combines the Sacrifice based Optimistic Concurrency Control (OPT-Sacrifice) and High Priority two-phase locking (HP2PL) algorithms together to support both optimistic and pessimistic shadow of each sub-transaction, has been proposed to increase the likelihood of successful timely commitment and to avoid unnecessary replication overload.

A Simplified Database-Oriented Web Framework

The paper firstly analyses disadvantages in the traditional Web database systems. And then it puts forward a simplified framework called database-oriented Web framework (DOWF). In this framework, the pages and the data are all managed by database system. In order to get keywords or search a special page, which the users accessed before, users access the static pages by common script procedure (CSP), and access the dynamic pages by functional script procedure (FSP) and CSP. The article expounds the method how to implement DOWF in details. The paper also analyses the mechanism of a DOWF site by implementing a prototype system. At last, the article gives the features of DOWS in search, in security, in reuse of pages and in offline waiting, etc. Key words database-oriented - Web framework - common script procedure (CSP) - functional script procedure (FSP) CLC number TP 391 Foundation item: Supported by Natural Science Foundation of Jiangsu Province (BK2003030).Biography: ZHU Qiao-ming (1963-), male, professor, research direction: Web information processing chinses information processing.

A sensor transaction scheduling algorithm for maintaining real-time data temporal validity

A new scheduling algorithm called deferrable scheduling with time slice exchange (DS-EXC) was proposed to maintain the temporal validity of real-time data. In DS-EXC, the time slice exchange method was designed to further defer the release time of transaction instances derived by the deferrable scheduling algorithm (DS-FP). In this way, more CPU time would be left for lower priority transactions and other transactions. In order to minimize the scheduling overhead, an off-line scheme was designed. In particular, the schedule for a transaction set is generated off-line until a repeating pattern is found, and then the pattern is used to construct the schedule on-line. The performance of DS-EXC was evaluated by sets of experiments. The results show that DS-EXC outperforms DS-FP in terms of increasing schedulable ratio. It also provides better performance under mixed workloads.

Weak Serializable Concurrency Control in Distributed Real-Time Database Systems

Most of the proposed concurrency control protocols for real time database systems are based on serializability theorem. Owing to the unique characteristics of real time database applications and the importance of satisfying the timing constraints of transactions, serializability is too strong as a correctness criterion and not suitable for real time databases in most cases. On the other hand, relaxed serializability including epsilon serializability and similarity serializability can allow more real time transactions to satisfy their timing constraints, but database consistency may be sacrificed to some extent. We thus propose the use of weak serializability(WSR) that is more relaxed than conflicting serializability while database consistency is maintained. In this paper, we first formally define the new notion of correctness called weak serializability. After the necessary and sufficient conditions for weak serializability are shown, corresponding concurrency control protocol WDHP(weak serializable distributed high priority protocol) is outlined for distributed real time databases, where a new lock mode called mask lock mode is proposed for simplifying the condition of global consistency. Finally, through a series of simulation studies, it is shown that using the new concurrency control protocol the performance of distributed real time databases can be greatly improved.

Concurrency Control of Single-Level Transaction in WHYMX Object-Oriented Database System

The data model of WHYMX complicates transaction management. Traditional locking method is not powerful enough to solve the new problem of concurrency control of WHYMX's transaction. This paper presents a number of concurrency control algorithms based on the extended locking method.

Validation concurrency control protocol in parallel real-time database systems

In parallel real-time database systems, concurrency control protocols must satisfy time constraints as well as the integrity constraints. The authors present a validation concurrency control(VCC) protocol, which can enhance the performance of real-time concurrency control mechanism by reducing the number of transactions that might miss their deadlines, and compare the performance of validation concurrency control protocol with that of HP2PL(High priority two phase locking) protocol and OCC-TI-WAIT-50(Optimistic concurrency control-time interval-wait-50) protocol under shared-disk architecture by simulation. The simulation results reveal that the protocol the author presented can effectively reduce the number of transactions restarting which might miss their deadlines and performs better than HP2PL and OCC-TI-WAIT-50. It works well when arrival rate of transaction is lesser than threshold. However, due to resource contention the percentage of missing deadline increases sharply when arrival rate is greater than the threshold.

Circumstance of endoscopic and laparoscopic treatments for gastric cancer in Japan: A review of epidemiological studies using a national administrative database

Currently, endoscopic submucosal dissection(ESD) and laparoscopic gastrectomy(LG) have become widely accepted and increasingly play important roles in the treatment of gastric cancer. Data from an administrative database associated with the diagnosis procedure combination(DPC) system have revealed some circumstances of ESD and LG in Japan. Some studiesdemonstrated that medical costs or length of stay of patients receiving ESD for gastric cancer had become significantly reduced while length of hospitalization and costs were significantly increased in older patients. With respect to LG, some recent reports have shown that this has been a cost-beneficial treatment for patients compared with open gastrectomy while simultaneous LG and cholecystectomy is a safe procedure for patients with both gastric cancer and gallbladder stones. These epidemiological studies using the administrative database in the DPC system closely reflect clinical circumstances of endoscopic and surgical treatment for gastric cancer in Japan. However, DPC database does not contain detailed clinical data such as histological types and lesion size of gastric cancer. The link between the DPC database and another detailed clinical database may be vital for future research into endoscopic and laparoscopic treatments for gastric cancer.

A solution for concurrency control and long transaction management in SDBMS

The problem of long transactions is a significant problem in spatial database. The checkout mechanism and multi version mechanism are two kind methods of solving the problem of long transactions. In this paper, we present a Shallow Version Management mechanism to realize multi version mechanism in spatial database. And we introduced a increment storage and dynamic version views building method to improve efficiency of storing and consulting. We also illuminate how to resolve the problem of long transaction concurrency control in spatial database by using multi version mechanism. At the end of this paper, we introduce some required means to version management in spatial database, like converge, compress and delete.

TRANSACTION MANAGEMENT IN DISTRIBUTED DATABASE SYSTEM C-POREL

This paper covers the transaction management of C-POREL, i. e. the distributed rela-tional data base management system on a microcomputer network. Presented in the pa-per are the concurrency control strategy of transactions in C-POREL, the mechanism ofthe local and global recovery, the reliable state control protocol RSC for getting the ro-bustness of the network and the protocol for processing distributed multisite transactions,and the outline of the architecture of the transaction manager TM of C-POREL.

Resources Snapshot Model for Concurrent Transactions in Multi-Core Processors

Transaction parallelism in database systems is an attractive way of improving transaction performance. There exists two levels of transaction parallelism, inter-transaction level and intra-transaction level. With the advent of multi- core processors, new hopes of improving transaction parallelism appear on the scene. The greatest execution efficiency of concurrent transactions comes from the lowest dependencies of them. However, the dependencies of concurrent transactions stand in the way of exploiting parallelism. In this paper, we present Resource Snapshot Model （RSM） for resource modeling in both levels. We propose a non-restarting scheduling algorithm in the inter-transaction level and a processor assignment algorithm in the intra-transaction level in terms of multi-core processors. Through these algorithms, execution performance of transaction streams will be improved in a parallel system with multiple heterogeneous processors that have different number of cores.

An Object-Oriented Transaction Model

In object-oriented database systems(OODBSs),the traditional transaction models are no longer suit- able because of the difference between the object-oriented data model(OODM)and the conventional da- ta models(e.g.relational data model).In this paper,transaction models for advanced databuse applica- tions are reviewed and their shortcomings are analyzed.Exchangeability of operations is proposed in- stead of commuativity and recoverability for using more semantics in transaction management.As a result,an object-oriented transaction model(in short,OOTM)is presented.It is not modeled for some special application,but directly based on object-oriented paradigms.A transaction is regarded as an interpretation of a method.Each transaction(even subtransactions)keeps relative ACID(Atomicity, Consistency,Isolation,Durability )properties,therefore the special problems appearing in OODBSs such as“long transactions”,“visibility of inconsistent database state”can be solved.

Design and Implementation of a Concurrency Control Mechanism in an Object-Oriented Database System

This paper presents a practical concurrency control mechanism - ObjectLockingin OODBMS. Object-Locking can schedule transactions, each of themcan be considered as a sequence of high level operations defined on classes. Bythe properties of parallelity and coatativity between high level operations,proper lock modes for each operation are desigued and the compatibility matrixis constructed. With these lock modes, phatoms are kept away from databasesand a high degree of concurrency is achieved.

Databases fit for blockchain technology:A complete overview

Efficient data storage and query processing systems play a vital role in many different research areas.Blockchain technology and distributed ledgers attract massive attention and trigger multiple projects in various industries.Nevertheless,blockchain still lacks the features of a Database Management System(DBMS or simply databases),such as high throughput,low latency,and high capacity.For that purpose,there have been many proposed approaches for handling data storage and query processing solutions in the blockchain.This paper presents a complete overview of many different DBMS types and how these systems can be used to implement,enhance,and further improve blockchain technology.More concretely,we give an overview of 10 transactional,an extensive overview of 14 analytical,9 hybrids,i.e.,translytical,and 13 blockchain DBMSs.We explain how database technology has influenced the development of blockchain technology by unlocking different features,such as Atomicity,Consistency,Isolation,and Durability(ACID),transaction consistency,rich queries,real-time analysis,and low latency.Using a relaxation approach analogous to the one used to prove the Consistency,Availability,Partition tolerance(CAP)-theorem,we postulate a“Decentralization,Consistency,and Scalability(DCS)-satisfiability conjecture”and give concrete strategies for achieving the relaxed DCS conditions.We also provide an overview of the different DBMSs,emphasizing their architecture,storage manager,query processing,and implementation.

支持混合事务和分析处理的数据库管理系统综述

数据库管理系统根据应用场景分为事务型(OLTP)系统和分析型(OLAP)系统.随着实时数据分析需求增长,OLTP任务和OLAP任务混合的场景越来越普遍,业界开始重视支持混合事务和分析处理(HTAP)的数据库管理系统.这种HTAP数据库系统除了需要满足高性能的事务处理外,还需要满足实时分析对数据新鲜度的要求.因此,对数据库系统的设计与实现提出了新的挑战.近年来,在工业界和学术界涌现了一批架构多样、技术各异的原型和产品.综述HTAP数据库的背景和发展现状,并且从存储和计算的角度对现阶段的HTAP数据库进行分类.在此基础上,按照从下往上的顺序分别总结HTAP系统在存储和计算方面采用的关键技术.在此框架下介绍各类系统的设计思想、优劣势以及适用的场景.此外,结合HTAP数据库的评测基准和指标,分析各类HTAP数据库的设计与其呈现出的性能与数据新鲜度的关联.最后,结合云计算、人工智能和新硬件技术为HTAP数据库的未来研究和发展提供思路.

多副本分布式事务处理关键技术及典型数据库系统综述

数据复制是分布式数据库提高可用性的重要手段,通过在不同区域放置数据库的部分副本,还可以提高本地读写操作的响应速度,增加副本数量也会提升读负载的线性扩展能力.考虑到这些优良特性,近年来国内外都出现了众多多副本分布式数据库系统,包括Google Spanner、CockroachDB、TiDB、OceanBase等一系列主流的工业界系统,也出现了包括Calvin、Aria、Berkeley Anna等一系列优秀的学术界系统.然而,多副本数据库带来诸多收益的同时,也带来了一致性维护、跨节点事务、事务隔离等一系列挑战.总结分析现有的复制架构、一致性维护策略、跨节点事务并发控制等技术,对比几个代表性多副本数据库系统之间在分布式事务处理方面上的差异与共同点,并在阿里云环境下搭建跨区域的分布式集群环境,对几个代表性系统的分布式事务处理能力进行了实验测试分析.

OceanBase分布式关系数据库架构与技术

关系数据库是当今社会的关键信息基础设施,互联网和数字化带来了高并发和海量数据,传统关系数据库均为集中式架构,处理能力和存储容量都捉襟见肘.OceanBase分布式关系数据库基于通用PC服务器,不仅实现了在线水平伸缩,还实现了机房故障自动无损容灾以及高倍率数据压缩等,已经应用于金融、政务、通信和互联网等行业.介绍了OceanBase分布式关系数据库的系统架构和关键技术,包括分布式事务处理、基于LSM-tree的存储系统以及分布式SQL优化器.详细阐述了OceanBase数据库的高可用和数据一致性,包括RPO为0和RTO小于8 s.也介绍了OceanBase数据库多租户机制,即采用了集群内原生多租户设计,在集群内实现多个互相独立的数据库服务.基于Sysbench和TPC-H评测基准,对比实验结果表明:1)在单机模式下,OceanBase的性能是MySQL的1.27倍至2倍多;2)在单主模式下,OceanBase的性能是MySQL的1.25倍至近2倍;3)在多主模式下,OceanBase的性能是MySQL的1.09倍至3.1倍,对于OLAP的复杂查询,OceanBase的性能是MySQL的6倍到327倍.

跨域双活数据库事务处理的动态优化技术

跨域双活数据库能为企业提供灾备能力,但传统的灾备节点仅提供备份功能,无法为主服务器分担读写负载,造成了系统瓶颈。如今分布式数据库领域的数据复制架构、数据库节点间共识协议等,为异地双活数据库的发展提供了理论基础。在跨域双活的场景下提出一种基于多主架构的确定性事务处理方案,在原有的承担灾备的基础上提供客观的负载均衡能力。在该架构中,使用确定性乐观并发控制协议保证跨域双活场景下事务执行的正确性,同时应用异步冲突检测优化与动态批大小设置调整系统负载以适应网络环境的变化。在TPC-C基准测试中验证架构的原型实现系统的性能,在网络利用率与事务吞吐量上均取得了较好的效果,与原始分片方案相比事务处理性能提升18%~23%,网络延迟下降了26%~31%。