Two of these, page inventory and pointer are used for space management. For those not familiar with InterBase's on-disk structure, here is a brief description of each of the page types. Page Types All page types include a header that holds generic page information. Secondary database files also have header pages. Any data page contains data for only one table.
Any blob page contains data for only one blob.
The bit indicates whether the page is currently in use. Page inventory pages occur at fixed intervals in the database - the interval is determined by the page size. It contains an array of page numbers for the data pages of the table and a corresponding array of bits that indicate whether the page is full. No pointer page entry is made for blob pages or pages that contain only the second or subsequent pages of data from a fragmented record. The only odd thing is that each table can have only one index root page.