purpose of paging the page tables in os
Page table There is normally one hash table, contiguous in physical memory, shared by all processes. A per-process identifier is used to disambiguate the pages of different processes from each other. It is somewhat slow to remove the page table entries of a given process; the OS may avoid reusing per-process identifier values to delay facing this. Alternatively, per-process hash tables may be used, but they are impractical because of memory fragmentation, which requires the tables to be pre-allocated.
Solid-state drive A solid-state drive (SSD) is a solid-state storage device that uses integrated circuit assemblies as memory to store data persistently. It is also sometimes called solid-state disk;[1] the word "disk" is inappropriate since SSDs do not have physical disks. SSDs primarily use traditional hard disk drive (HDD) interfaces, such as SATA and SAS, greatly simplfying usage of SSDs in computers.[2] Following the initial acceptance of SSDs with HDD interfaces, new I/O interfaces like M.2 and U.2 have been designed to address specific requirements of the Flash memory technology used in SSDs.