Recent progress on the memristive devices owing to the multi-functional approach have surged the exploration of new functional materials. Here, we have incorporated two-dimensional (2D) halide perovskite in memristive device. The Pb-free Cs3Bi2I9 perovskite active layer was fabricated to obtain the ITO/Cs3Bi2I9/Pt structure. The device shows typical bipolar resistance switching behavior with Off state resistance in TΩ scale. Due to the higher work function of the top Pt electrode, the barrier height at the Pt/Cs3Bi2I9 junction is higher and the observed device conductance is low in the Off state. Enhanced memory parameters such as endurance (>103 cycles) and retention (104 s) for multiple conductance states is observed. In the pulse modulated synaptic characterization, the device emulated essential post-synaptic plasticity, short-term and long-term potentiation with power consumption in femto Joule. The classical conditioning learning was mimicked by the device by electric and optical stimulation procuring basic associative training. The non-toxicity of the perovskite material has been successfully utilized for the transient memristor application. The robust in-memory photonic memristive property of the device along with water stimulated transient behavior demonstrates the significance of the proposed device in multi-dimensional field of electronic device.