the function can be executed in parallel mode, but the execution is restricted to parallel group leader. PARALLEL SAFE indicates that the function is safe to run in parallel mode without restriction. g., setseed() cannot be executed other than by the group leader because a change made by another process would not be reflected in the leader). In general, if a function is labeled as being safe when optimizer_jit_above_cost optimizer_jit_inline_above_cost optimizer_jit_optimize_above_cost parallel_leader_participation parallel_setup_cost parallel_tuple_cost primary_conninfo VMware Greenplum 7 Documentation