Key Fields in a Database. Keys are crucial to a table structure for many reasons, some of which are identified below: 1  They ensure that each record in a table is precisely identified.  They help establish and enforce various types of integrity.
avifauna definition: The definition of avifauna are the birds that live in a certain place or at a certain time. (noun) An example of avifauna is penguins living primarily in Antarctica. An example of avifauna is the moa of New Zealand becoming extin...
The noun VENA CAVA has 1 sense: 1  1. either of two large veins that return oxygen-depleted blood to the right atrium of the heart. 2  Meaning: 3  Either of two large veins that return oxygen-depleted blood to the right atrium of the heart. 4  Classified under: 5  Nouns denoting body parts. 6  Hypernyms (vena cava is a kind of...): vein; vena; venous blood vessel (a blood vessel that carries blood from the capillaries toward the heart) Hyponyms (each of the following is a kind of vena cava): inferior vena cava; postcava (receives blood from lower limbs and abdominal organs and empties into the posterior part of the right atrium of the heart; formed from the union of the two iliac veins)