  We present the second major release of data from the SAMI Galaxy Survey. Data
Release Two includes data for 1559 galaxies, about 50% of the full survey.
Galaxies included have a redshift range 0.004 < z < 0.113 and a large stellar
mass range 7.5 < log (M_star/M_sun) < 11.6. The core data for each galaxy
consist of two primary spectral cubes covering the blue and red optical
wavelength ranges. For each primary cube we also provide three spatially binned
spectral cubes and a set of standardised aperture spectra. For each core data
product we provide a set of value-added data products. This includes all
emission line value-added products from Data Release One, expanded to the
larger sample. In addition we include stellar kinematic and stellar population
value-added products derived from absorption line measurements. The data are
provided online through Australian Astronomical Optics' Data Central. We
illustrate the potential of this release by presenting the distribution of
~350,000 stellar velocity dispersion measurements from individual spaxels as a
function of R/R_e, divided in four galaxy mass bins. In the highest stellar
mass bin (log (M_star/M_sun)>11), the velocity dispersion strongly increases
towards the centre, whereas below log (M_star/M_sun)<10 we find no evidence for
a clear increase in the central velocity dispersion. This suggests a transition
mass around log (M_star/M_sun) ~10 for galaxies with or without a
dispersion-dominated bulge.
