That depends on your definition of high-availability. If high availability includes distributed writers, (global) sequences are not the best solution because generating unique sequence values requires synchronisation between all writers. In those cases, you might need to explicitly partition the ID space so that individual writers are guaranteed not to get in each others' hair.
That depends on your definition of high-availability. If high availability includes distributed writers, (global) sequences are not the best solution because generating unique sequence values requires synchronisation between all writers. In those cases, you might need to explicitly partition the ID space so that individual writers are guaranteed not to get in each others' hair.
That is merely a sequence generation strategy.