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
It consists of fields (columns), and rows. In relational databases and flat file databases, a table is a set of data elements (values) using a model of vertical columns (identifiable by name) and horizontal rows, the cell being the unit where a row and column intersect.he data in a table does not have to be physically stored in the database. Views also function as relational tables, but their data are calculated at query time. External tables (in Informix or Oracle, for example) store data outside standard database structures but accessible to database commands.