What is the meaning of row segments in the output of sa_table_fragmentation.
asked 15 Apr '11, 12:14
A row segment is a portion of a row that is not stored contiguously with the row header, or other row segments, for the same row. "Not stored contiguously" means a separate database page.
In SQL Anywhere, there is no limit on the size of a row (though a row is limited to 45K columns). If you had 4K pages, then rows that average 8K would (probably) consist of (roughly) two row segments each. However, if rows grow - because of updates - then the server may have no choice but to split a row segment into two, because there may not be enough room on the same page to store the longer values.
answered 15 Apr '11, 12:34