More and more individuals, companies and organizations are relying on the cloud to store and manage their data, which translates into increasing pressure on the cloud infrastructure. Cloud data can be very diverse, including a wide variety of personal data collections, very large multimedia content repositories and very large datasets. Users and application developers can be in very high numbers, with little DBMS expertise. Data-intensive applications can be very diverse too, with requirements ranging from basic database capabilities to complex analytics over big data. In particular, the pay-as-you-go model makes the cloud attractive for supporting novel large-scale elastic applications. NoSQL solutions for the cloud, for instance, have traded consistency and transactional guarantees for scalability. However, the grand challenge for a data-intensive cloud infrastructure is to provide ease of use, consistency, privacy, scalability and elasticity, simultaneously, over cloud data. Addressing this challenge requires novel solutions across the spectrum of data management techniques, including massive data storage, elastic parallel query processing, transactions over data replicated at geographically distributed sites, security and privacy, and efficient data loading and access. This special section focuses on recent advances in research and development in data-intensive cloud infrastructures.