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Type Inference and Type Checking for Queries on Execution Traces
, 2008
"... This paper studies, for the first time, the management of type information for an important class of semi-structured data: nested DAGs (Directed Acyclic Graphs) that describe execution traces of business processes (BPs for short). Specifically, we consider here type inference and type checking for q ..."
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Cited by 15 (10 self)
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This paper studies, for the first time, the management of type information for an important class of semi-structured data: nested DAGs (Directed Acyclic Graphs) that describe execution traces of business processes (BPs for short). Specifically, we consider here type inference and type checking for queries over BP execution traces. The queries that we consider select portions of the traces that are of interest to the user; the types describe the possible shape of the execution traces in the input/output of the query. We formally define and characterize here three common classes of BP execution traces and their respective notions of type inference and type checking. We study the complexity of the two problems for query languages of varying expressive power and present efficient type inference/checking algorithms whenever possible. Our analysis offers a nearly complete picture of which combinations of trace classes and query features lead to PTIME algorithms and which to NP-complete or undecidable problems.
TOP-K Projection Queries for Probabilistic Business Processes
"... A Business Process (BP) consists of some business activities undertaken by one or more organizations in pursuit of some business goal. Tools for querying and analyzing BP specifications are extremely valuable for companies. In particular, given a BP specification, identifying the top-k flows that ar ..."
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Cited by 11 (6 self)
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A Business Process (BP) consists of some business activities undertaken by one or more organizations in pursuit of some business goal. Tools for querying and analyzing BP specifications are extremely valuable for companies. In particular, given a BP specification, identifying the top-k flows that are most likely to occur in practice, out of those satisfying the criteria of a given query, is crucial for various applications such as personalized advertisements and BP web-site design. This paper studies, for the first time, top-k query evaluation for queries with projection in this context. We analyze the complexity of the problem for different classes of distribution functions for the flows likelihood, and provide efficient (PTIME) algorithms whenever possible. Furthermore, we show an interesting application of our algorithms to the analysis of BP execution traces (logs), for recovering missing information about the run-time process behavior, that has not been recorded in the logs. 1
Evaluating top-k queries over business processes
"... Abstract — A Business Process (BP) consists of some business activities undertaken by one or more organizations in pursuit of some business goal. Tools for querying and analyzing BP specifications are extremely valuable for companies as they allow to optimize the BP, identify potential problems, and ..."
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Cited by 7 (2 self)
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Abstract — A Business Process (BP) consists of some business activities undertaken by one or more organizations in pursuit of some business goal. Tools for querying and analyzing BP specifications are extremely valuable for companies as they allow to optimize the BP, identify potential problems, and reduce operational costs. In particular, given a BP specification, identifying the top-k execution flows that are most likely to occur in practice out of those satisfying the query criteria, is crucial for various applications. To address this need, we introduce in this paper the notion of likelihood for BP execution flows, and study top-k query evaluation (finding the k most likely matches) for queries over BP specifications. We analyze the complexity of query evaluation in this context and present novel algorithms for computing topk query results. To our knowledge, this is the first paper that studies such top-k query evaluation for BP specifications. I.
Modeling and verifying security policies in business processes
- In Proc. of BPMDS’14
"... Abstract. Modern information systems are large-sized and comprise multiple heterogeneous and autonomous components. Autonomy enables decentralization, but it also implies that components providers are free to change, retire, or intro-duce new components. This is a threat to security, and calls for a ..."
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Cited by 5 (3 self)
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Abstract. Modern information systems are large-sized and comprise multiple heterogeneous and autonomous components. Autonomy enables decentralization, but it also implies that components providers are free to change, retire, or intro-duce new components. This is a threat to security, and calls for a continuous veri-fication process to ensure compliance with security policies. Existing verification frameworks either have limited expressiveness—thereby inhibiting the specifi-cation of real-world requirements—, or rely on formal languages that are hardly employable for modeling and verifying large systems. In this paper, we overcome the limitations of existing approaches by proposing a framework that enables: (1) specifying information systems in SecBPMN, a security-oriented extension of BPMN; (2) expressing security policies through SecBPMN-Q, a query lan-guage for representing security policies; and (3) verifying SecBPMN-Q against SecBPMN specifications via an implemented query engine. We report on the ap-plicability of our approach via a case study about air traffic management.
Querying Web-Based Applications Under Models of Uncertainty
, 2008
"... Many businesses offer their services to customers via Webbased application interfaces. Reasoning about execution flows of such applications is extremely valuable for companies. Such reasoning must often operate under terms of uncertainty and partial information, due to partial tracing, effects of un ..."
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Cited by 2 (0 self)
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Many businesses offer their services to customers via Webbased application interfaces. Reasoning about execution flows of such applications is extremely valuable for companies. Such reasoning must often operate under terms of uncertainty and partial information, due to partial tracing, effects of unknown external parameters, and more. The objectives of this research are (1) to define models for capturing Web application executions, with partial information and uncertainly of various flavors, (2) to design algorithms that allow for efficient reasoning over applications/execution traces under these models, and (3) to provide practical implementations that exploit these sound theoretical foundations for effective optimization of Web applications. We identify a restricted class of models that capture realistic scenarios, while allowing for an efficient query-based applications analysis. Hardness results indicate the necessity of such restricted models. We describe these results, highlight open problems, and consider directions for future research.
Type inference and type checking for queries over execution traces
, 2012
"... ... for queries over the execution traces of Business Processes. We define formal models for such execution traces, allowing to capture various realistic scenarios of partial information about these traces. We then define corresponding notions of types, and the problems of type inference and type ch ..."
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Cited by 1 (0 self)
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... for queries over the execution traces of Business Processes. We define formal models for such execution traces, allowing to capture various realistic scenarios of partial information about these traces. We then define corresponding notions of types, and the problems of type inference and type checking in this context. We further provide a comprehensive study of the decidability and complexity of these problems, in various cases, and suggest efficient algorithms where possible.
On Models and Query Languages for Probabilistic Processes
"... Probabilistic processes appear naturally in various contexts, with applications to Business Processes, XML data management and more. Many models for specifying and querying such processes exist in the literature; a main goal of research in this area is to design models that are expressive enough to ..."
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Probabilistic processes appear naturally in various contexts, with applications to Business Processes, XML data management and more. Many models for specifying and querying such processes exist in the literature; a main goal of research in this area is to design models that are expressive enough to capture real-life processes and analysis tasks, but at the same time allow for efficient query evaluation. We depict the model established in [13, 16, 17, 18], and claim that it achieves a good balance between expressivity and query evaluation complexity. We compare and contrast the model with other common models for probabilistic processes, highlighting the different choices made in models design and their effect on expressivity and incurred complexity.
Querying Contract Databases Based on Temporal Behavior
"... Considering a broad definition for service contracts (beyond web services and software, e.g. airline tickets and insurance policies), we tackle the challenges of building a high performance broker in which contracts are both specified and queried through their temporal behavior. The temporal dimensi ..."
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Considering a broad definition for service contracts (beyond web services and software, e.g. airline tickets and insurance policies), we tackle the challenges of building a high performance broker in which contracts are both specified and queried through their temporal behavior. The temporal dimension, in conjunction with traditional relational attributes, enables our system to better address difficulties arising from the great deal of information regarding the temporal interaction of the various events cited in contracts (e.g. "No refunds are allowed after a reschedule of the flight, which can be requested only before any flight leg has been used"). On the other hand, querying large repositories of temporal specifications poses an interesting indexing challenge. In this paper, we introduce two distinct and complementary indexing techniques that enable our system to scale the evaluation of a novel and theoretically sound notion of permission of a temporal query by a service contract. Our notion of permission is inspired by previous work on model checking but, given the specific characteristic of our problem, does not reduce to it. We evaluate experimentally our implementation, showing that it scales well with both the number and the complexity of the contracts. Categories and Subject Descriptors
