Store Atomicity for Transactional Memory

AbstractWe extend the notion of Store Atomicity [Arvind and Jan-Willem Maessen. Memory model = instruction reordering + store atomicity. In ISCA '06: Proceedings of the 33rd annual International Symposium on Computer Architecture, 2006] to a system with atomic transactional memory. This gives a fine-grained graph-based framework for defining and reasoning about transactional memory consistency. The memory model is defined in terms of thread-local Instruction Reordering axioms and Store Atomicity, which describes inter-thread communication via memory. A memory model with Store Atomicity is serializable: there is a unique global interleaving of all operations which respects the reordering rules and serializes all the operations in a transaction together. We extend Store Atomicity to capture this ordering requirement by requiring dependencies which cross a transaction boundary to point in to the initiating instruction or out from the committing instruction. We sketch a weaker definition of transactional serialization which accounts for the ability to interleave transactional operations which touch disjoint memory. We give a procedure for enumerating the behaviors of a transactional program—noting that a safe enumeration procedure permits only one transaction to read from memory at a time. We show that more realistic models of transactional execution require speculative execution. We define the conditions under which speculation must be rolled back, and give criteria to identify which instructions must be rolled back in these cases

HybridMiner: Mining Maximal Frequent Itemsets Using Hybrid Database Representation Approach

In this paper we present a novel hybrid (arraybased layout and vertical bitmap layout) database representation approach for mining complete Maximal Frequent Itemset (MFI) on sparse and large datasets. Our work is novel in terms of scalability, item search order and two horizontal and vertical projection techniques. We also present a maximal algorithm using this hybrid database representation approach. Different experimental results on real and sparse benchmark datasets show that our approach is better than previous state of art maximal algorithms.Comment: 8 Pages In the proceedings of 9th IEEE-INMIC 2005, Karachi, Pakistan, 200

Overdraft America: Confusion and Concerns About Bank Practices

Based on a survey, examines the prevalence of overdraft penalty and transfer fees by age and income, as well as consumer satisfaction with overdraft fee options. Makes policy recommendations

Checks and Balances: 2014 Update

This report is the fourth in a series by The Pew Charitable Trusts examining key checking account terms and conditions. In our first report, in 2011, "Hidden Risks: The Case for Safe and Transparent Checking Accounts", we studied and reported on the disclosures from the 10 largest banks in the United States by deposit volume. Our second report, in 2012, "Still Risky: An Update on the Safety and Transparency of Checking Accounts" expanded the research and examined the disclosures from the 12 largest banks as well as the 12 largest credit unions. In both reports we highlighted our policy recommendations, which urge the Consumer Financial Protection Bureau, or CFPB, to write new rules requiring financial institutions to: * Summarize key information about terms and fees in a concise, uniform format. * Provide accountholders with clear, comprehensive terms and pricing information for all available overdraft options.* Make overdraft penalty fees reasonable and proportional to the financial institution's costs in providing the overdraft loan. * Post deposits and withdrawals in a fully disclosed, objective, and neutral manner that does not maximize overdraft fees.* Prohibit pre-dispute mandatory binding arbitration clauses in checking account agreements, which prevent accountholders from accessing courts to challenge unfair and deceptive practices or other legal violations.This study and our 2013 report, "Checks and Balances: Measuring Checking Accounts' Safety and Transparency", rate the 50 largest banks based on how well their disclosure, overdraft, and dispute resolution practices meet these policy recommendations

Checks And Balances: 2015 Update

Checking accounts are a vital financial tool, utilized by 9 in 10 American households. This report provides the third annual evaluation of disclosure, overdraft, and dispute resolution policies and practices of 45 of the nation's 50 largest retail banks, totaling 66 percent of all domestic deposit volume. Pew's Model Summary Disclosure Box for Checking Accounts served as the template for rating each bank's disclosure documents to determine best or good practices for overdraft and dispute resolution. Additionally, this report identified trends among the 32 institutions examined in all three Checks and Balances reports to date. To ensure that all checking accounts are safe and transparent, Pew has also developed a set of policy recommendations and urges the Consumer Financial Protection Bureau to incorporate these policies in new rules on overdraft practices and arbitration clauses