Dialysis is a treatment that does some of the things done by healthy kidneys. It is needed when your own kidneys can no longer take care of your body's needs. When is dialysis needed? You need dialysis when you develop end stage kidney failure --usually by the time you lose about 85 to 90 percent of your kidney function and have a GFR of <15.
1. A table is perceived as a 2-dimensional structure composed of rows and columns 2. each table row(tuple) represents a single entity occurrence within an entity set 3. each table column represents an attribute and each column has a distinct name 4. each intersection of a row and column represents a single data value 5. all values in a column must conform to the same data format 6. each column has a specific range of values known as the attribute domain
The display of a table's contents in rows and columns, similar to a table or spreadsheet; each row is a separate record in the table, and each column contains the field values for one field in the table.