The setting of this variable determines whether or not Vision indexed file data blocks (as opposed to key blocks) will be held in the memory-resident disk buffers. When it is set to "1" (on, true, yes), both data blocks and key blocks will use the buffers. When set to "0" (off, false, no), only key blocks will use the buffers. Setting this value to "1" will usually improve performance unless very few buffers are being used.