Data buffers are Informix pages held in memory to reduce disk I/O. Pages are the smallest physical unit of storage, which is platform dependent and either 2 KB or 4 KB. In fact, Informix refers to each such page as a "buffer", and the sum of all buffers as the "data buffer cache."

The SAP/Informix database monitor shows current read and write quality in the buffers, that is, what percent of total reads and writes could be satisfied in the buffer without going to disk.