Due to the fact that page overflow is relatively rare the basic operations needed for appending are the search of the record, modification of the page information and writing of the page back to disk. If there is not enough space on the page for the new record the overflow procedure is performed. The standard practice with the binary trees is splitting of the page in two portions of the same size to allow the balanced growth of the tree. However, on the one hand, when the floating record size is used is not possible to split the page in two similar portions. On the other hand, at the stage of overflow some optimizations can improve overall database performance.
Overflow procedure handling page splitting produces the delimiter appended to the upper level.
The size of the delimiter directly affects the binary tree growth behavior. Namely, the shorter is the delimiter the slower would be the growth of the tree when the new entries are appended. For this reason it is effective to form the delimiter of the shortest possible size. The simplest way is to use the delimiter formed as the shortest differing portion of two successive records. Moreover, to find the split position it is possible to scan a number of records in the vicinity of the page center to determine the records with the shortest differing portions.