Some various types of systems used for knowledge management. The data mining technique, which is knowledge discovery technique, is used most often for the purpose of pattern recognition and finding the interesting relationship between data that can be used by various business to expand customer and profits. Data mining techniques can be also used for the purpose of other knowledge management processes.In this paper, initially, an overview of knowledge management is given. After that knowledge discovery process is explained. In the next section, an overview of data mining is given. In the last section, Data Mining: on Statistics and Pattern Recognition for Large Stores are discussed in which Wal-Mart is taken as a large store.In present context knowledge management refers to a range of practices (or best practises), that are used by organizations to identify, create, represent and distribute knowledge for the purpose of reuse, awareness and learning/training across the organizations. Knowledge management gives the organization a better way of achieving its organizational objectives. It is intended to lead to the achievement of specific outcomes, such as shared intelligence, improved performance, competitive advantage and a higher level of innovation.According to Awad amp. Ghaziri (2004), Knowledge management (KM) is a newly emerging, interdisciplinary business model that has knowledge within the framework of an organisation as its focus. Knowledge management promotes the creation, sharing and leveraging of the organization knowledge and focuses on organizing and making available important knowledge in the organization, wherever and whenever it needed. The knowledge can reside in the mind of an expert of the organization or in data that are stored in database warehouses. Moreover, the knowledge can be about process, procedures, intellectual property, documented best practises, lessons learned and solutions to recurring problems.