Research On Query Model Based On PCEDM

PCEDM, as the China Petroleum upstream data model, is one of key projects of the 'Eleventh Five-Year Plan', which integrates businesses of the exploration and development, and which is created by means of idea of POSC's Epicentre model. Because of PCEDM itself advanced characteristic and merging technique of complex object-oriented technology compared with the general relational data model, it becomes more complex during querying the data model.Currently, OpenWells software developed by landmark has become the oil data management software. Different from the maintenance process of the traditional exploration and development, it employs the way of batch view and maintained on data table, this software tends to hand-gathering and the unit of data maintenance is a single entity. Therefore, It does not satisfies users'custom for data maintenance and efficiency, and the operation for data is in single table, not several tables, the software has no longer meet the users' requirements in data query.In this thesis, some key technologies are researched, such as PCEDM data model, metadata model and the requirements of production data in oilfield, finally, a software is designed and implemented for query all kind of data in PCEDM. This system, whose key technique is metadata model, a series query meta-models are created, which supports general query based on metadata-driven technology. These meta-data models are employed to store all kinds of metadata information, including basic metadata, exploration and development of metadata, query conditions'metadata, logical metadata and physical and professional metadata and so on. These query meta-models can satisfy the personalized customization query by dynamically merging metadata information to achieve the meta-modeling on PCEDM and dynamically construct different combination and condition query in different oilfield data. Based on the query model mentioned above, we proposed the optimization model, which is mainly finding the best way to query and abstracting it to optimize function to achieve the dynamic Optimization by constructing the matching relations between the dynamic SQL and optimize function. At the same time, we make use of the cache technology and materialized view to store the view checked-off. This method avoids repeatedly access database and improves the efficiency of the query on PCEDM data.Finally, the query software is applied to oilfield, it shows that this model could simplify the query process and optimize the data.