Sessions and Cookies A cookie is a small piece of text containing identifying information Sent by server to browser Sent on first interaction,to identify session Sent by browser to the server that created the cookie on further interactions part of the HTTP protocol Server saves information about cookies it issued,and can use it when serving a request .E.g.,authentication information,and user preferences Cookies can be stored permanently or for a limited time Database System Concepts-7th Edition 9.15 ©Silberscha乜，Korth and SudarshanDatabase System Concepts - 7 9.15 ©Silberschatz, Korth and Sudarshan th Edition Sessions and Cookies ▪ A cookie is a small piece of text containing identifying information • Sent by server to browser ▪ Sent on first interaction, to identify session • Sent by browser to the server that created the cookie on further interactions ▪ part of the HTTP protocol • Server saves information about cookies it issued, and can use it when serving a request ▪ E.g., authentication information, and user preferences ▪ Cookies can be stored permanently or for a limited time