be allocated as private memory as the number of user session threads concurrently executing in the system increases however the number of allocatable cache memory blocks stored on the free list decreases the use of a single dedicated collector thread 90 can reduce performance of the system because after requesting a memory block if the free list is empty a user session thread must wait until the single dedicated collector thread 90 reclaims a memory block and stores it on the free list to improve performance the collector function can be distributed amongst the user threads fig5 illustrates another embodiment of the page management system shown in fig1 the dedicated collector thread 90 in the embodiment described in conjunction with fig2 is replaced by a plurality of user thread collectors 114 a c a plurality of user threads 112 a c execute in the thread manager 17 with each user thread 112 a c having a respective user thread collector 114 a c the page management system also includes a cache 18 and a paging manager 15 the cache 18 includes a plurality of page buffers 84 and a plurality of page control blocks u201c pcb u201d s 82 with each page buffer 84 having an associated page control block 82 the paging manager 15 includes an initialization routine 108 and a private workspace 41 and global or public workspace 45 the private workspace 41 and global workspace 45 have been described earlier in conjunction with fig2 the initialization routine 108 in the paging manager 106 allocates page buffers 84 in cache 102 and initializes the page control blocks 82 associated with each page buffer 84 before any of the user threads 112 a c execute in database management system.