Some large projects change or influence astronomy profoundly. Hipparcos pioneered space astrometry and Gaia took it to the next level. The first Gaia data release shows some of the potential of the 'billion star surveyor'. The Gaia catalogues will underpin several future astronomy endeavours such as LSST which will in turn usher in a new era in ground-based astronomy. Making projects like Gaia and LSST work is challenging (and very interesting). In the era of big data the petabytes of Gaia data and even the hundreds of petabytes of LSST data are not enormous - but for astronomy this is still challenging territory. Some define big data more in terms of complexity, not just volume, and here the astronomical data from Gaia and LSST is definitely big. In this talk we will cover some of the big data issues and technologies being used and look at how to deal with them.