Lattice-based cryptography is one of the most competitive algorithms in post-quantum algorithms. The discrete Gaussian sampler is a fundamental building block in lattice-based cryptography, but it is still challenging to construct a generic, efficient and secure discrete Gaussian sampler. In this work, we survey the existing discrete Gaussian samplers and summarize the characteristics and improvements of each sampler in detail. In addition, we discuss the evaluation criteria for samplers which we believe that a good scheme should use less preci...