Question $1$

$1.$ Let$$s consider an Employee relation described by the following attributes: emptID, empName,empAddress and empPhone.

a$.$ Explain how the information of the following row of the Employee relation $(1,$Ahmad$,$Riyadh$,1134322)$ are stored in a Key$-$Value store.

b$.$ Write the pseudo$-$code of a function called setEmpAttr allowing to store the value of a single attribute of a given employee in a Key$-$value store. The function setEmpAttr receives $3$ parameters employeeID, AttributeName and Value. It stores Value as the value of the attributeAttributeName of the employee identified by employeeID.

c$.$ Write the pseudo$-$code of a function called getEmpAttr allowing to retrieve the value of a singleattribute of a given employee in a Key$-$value store. The function getEmpAttr receives $2$ parameters employeeID and AttributeName. It returns the value of the attribute AttributeName of the employee identified by employeeID.

$2.$ Explain the principle of recursive query processing of put and get queries in a directory based architecture of a Key$-$Value store.