# When large page size is not desirable

- Limited memory

  Large database pages reduce I/O time because Derby can access more data with fewer I/Os. However, large pages require more memory. Derby allocates a bulk number of database pages in its page cache by default. If the page size is large, the system might run out of memory.

  Here's a rough guideline: If the system is running Windows 95 and has more than 32 MB (or Windows NT and has more than 64 MB), it is probably beneficial to use 8K rather than 4K as the default page size.

  Use the -mx flag as an optional parameter to the JVM to give the JVM more memory upon startup.

  For example:

      java -mx64 myApp

- Limited disk space

  If you cannot afford the overhead of the minimum two pages per table, keep your page sizes small.

Parent topic: Performance trade-offs of large pages
Related concepts
When large page size does not improve performance