نتایج جستجو برای: dbas
تعداد نتایج: 119 فیلتر نتایج به سال:
To obtain good system performance, a DBA must choose a set of indices that is appropriate for the workload. The system can aid in this challenging task by providing recommendations for the index configuration. We propose a new index recommendation technique, termed semi-automatic tuning, that keeps the DBA “in the loop” by generating recommendations that use feedback about the DBA’s preferences...
In this paper we study the problem of minimising deterministic automata over finite and infinite words. Deterministic finite automata are the simplest devices to recognise regular languages, and deterministic Büchi, Co-Büchi, and parity automata play a similar role in the recognition of ω-regular languages. While it is well known that the minimisation of deterministic finite and weak automata i...
Being able to express and enforce role-based access control on XML data is a critical component of XML data management. However, given the semi-structured nature of XML, this is non-trivial, as access control can be applied on the values of nodes as well as on the structural relationship between nodes. ACXESS introduces a notion of security views to enforce access control for XML data repositor...
Purpose: Photon counting (PC) computed tomography (CT) can provide material selective CT imaging at lowest patient dose but it suffers from suboptimal count rate. A dynamic beam attenuator (DBA) can help with count rate by modulating x-ray beam intensity such that the low attenuating areas of the patient receive lower exposure, and detector behind these areas is not overexposed. However, DBA ma...
Vertical and Horizontal partitions allow database administrators (DBAs) to considerably improve the performance of business intelligence applications. However, finding and defining suitable horizontal and vertical partitions is a daunting task even for experienced DBAs. This is because the DBA has to understand the physical query execution plans for each query in the workload very well to make ...
Index structures are a widely used function of Database Management Systems (DBMS) in order to tune them for a special purpose. Finding the right index configuration is on the one hand extremely complex (NP-problem [6]) and a variation of the Knapsack Problem [9] but on the other hand manual configuration requires high administrative effort by cost-intensive experts (like DBAs). Regarding these ...
In this paper we conceptualize the database layout problem as a state space search problem. A state is a given assignment of tables to computer servers. We begin with a database and collect, for use as a workload input, a sequence of queries that were executed during normal usage of the database. The operators in the search are to fully replicate, horizontally partition, vertically partition, a...
Dynamic Bandwidth Allocation is a major open research challenge in the migration of Passive Optical Network (PON) systems towards Long Reach PON, especially when hybrid WDM/TDM is used (LR WDM/TDM PON). New and efficient solutions for Dynamic Bandwidth and Wavelength Assignment are sought to address two main critical issues of such PON systems: how to schedule the transmissions over multiple wa...
Autonomous Selection of Indexes and Materialized Views in Two Commerical Database Management Systems
The selection of the most beneficial indexes and materialized views (MVs) is a well-known issue in physical database design. The chosen set of indexes and MVs is crucial to the overall performance of the DBMS as it relates to specific workloads. Since this is such an important aspect of physical database design, database administrators (DBAs) spend a great amount of time selecting the best inde...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید