Each page table entry contains a present bit to indicate whether the page is in main memory or not. The entire page table may take up too much main memory. Since a page table will generally require several pages to be stored.
Page faults rise.
But the issue is non trivial. Hence some processors are now supporting multiple page sizes. Typically, each process has its own segment table See Figure 8. To combine their advantages some processors and OS page the segments. Several combinations exists.