Reload Analyzer Manual

Tandem Reload Analyzer Manual Page 21 of 42
A file does not have to be misused to become disorganized. Over the life of a file,
these operations can cause it to become disorganized, namely:
 Random inserts that cause block splits
 Deletions of the last record in the data block that cause the block to collapse
 Updates with record length changes that cause the record to no longer fit in its
current data block
In Figure 1-2, suppose all records in the data block starting with Carol’s record are
deleted, causing it to collapse. When the last record in that block is deleted, DP2
removes the block from the chain. That data block becomes a free or empty data
block. Because the free data block is no longer in the chain, the pointer from the index
block is deleted to that data block. Figure 1-3 shows what happens to the file. Note the
empty or free block in the file.