Applications drive innovation. The advance of database technology is achieved in support of development of mainstream applications effectively and efficiently. OLTP, OLAP, and online machine learning modeling today all follow this trend. Machine learning extracts knowledge and realizes predictive analysis by modeling data, is the main approach of artificial intelligence technology. This work studies the training process of machine learning from the perspective of data management, summarizes data management technology through data selection, data storage, data access, automatic optimization, and system implementation, and analyzes the advantages and disadvantages of these techniques. Based on the analysis, this study proposes key challenges of data management technology for online machine learning.