Iron metallicity distribution (MD) of RGB stars obtained with the automatic procedure (red shaded histogram) compared with the MD of Zoccali et al. (2008) (left panel, black line) and with the MD of the red clump stars (right panel, black line). The new RGB MD is in total agreement with the red clump one (right panel) but is shifted toward high metallicities compared to the MD of Zoccali et al. (2008) (left panel). This small difference is due to the difference in analysis of the two samples as explained in the text.