Behavior of the odd-Z elements [Na/Fe] and [Al/Fe] abundance ratios as a function of [Fe/H] for GES, Sequoia, Antaeus, ED-2, and ED-3 stars (green, brown, blue, magenta, and orange, respectively). Red arrows indicate the upper limits. The errorbars in the lower-left corner indicate the typical uncertainties. The MW literature data for Na abundances are taken from Edvardsson et al. (1993), Fulbright (2000), Stephens & Boesgaard (2002), Gratton et al. (2003), Reddy et al. (2003, 006), Bensby et al. (2005, 2014), Roederer et al. (2014) and Reggiani et al. (2017). The APOGEE control sample, as defined in Sect. 6, is plotted as a 2D histogram, where black and white colors stand for low and high density regions, respectively.