Metallicities derived from SDSS spectra (LR) compared to those of independent analysis of the same stars (ext). The black dots are the TOPoS sample (see text); the data are provided in Table B.1. The red dots are the PASTEL sample (see text); the data is provided in Table B.2. The green dots are data from Caffau et al. (2018), and open symbols are stars with uncertain abundance according to Caffau et al. (2018). The blue dots are data from Caffau et al. (2020). The stars circled in black are removed from the average (see text).