Applying data cleaning in Changqing Oilfield Company's data warehouse

In past ten years, Changqing Oilfield Company had constructed many information systems, mess of data had been collected in database. A great deal of knowledge and experience was embedded in these databases. To get the useful information, we must assure that all the data in the database are accurate, integrated, consistent and unique, so cleaning data of errors in structure and content is very important for data warehousing and integration. In this paper, we discussed the data quality problems appeared in the raw data, and the workflow of the data cleaning is described. For different type of the data, we adopted several cleaning method to process, details of the methods are also given in the paper. We had applied the data cleaning approaches in practice and achieved the ideal result.