| Date | May 2019 | Marks available | 2 | Reference code | 19M.3.HL.TZ0.1 |
| Level | HL | Paper | 3 | Time zone | no time zone |
| Command term | Identify | Question number | 1 | Adapted from | N/A |
Question
Refer to the Paper 3 Case study: a new computer aided dispatch system for Bangbai, available under the "Your tests" tab > supplemental materials.
The emergency management information system (EMIS) has a multitier architecture.
Identify two functions of the Data Tier of the EMIS.
Identify two characteristics of a TCP/IP Socket.
Markscheme
Award [2 max].
Award [1] for any valid function up to [2 max].
Stores/retrieves/searches/edits the data;
Encapsulates/holds the code for the database (accept DML / SQL or any other language);
Abstracts/Simplifies access to the databases;
Personalises the SQL for different databases (e.g. contains optimised queries for Oracle, MySQL etc.);
Manages the transactions (anything relating to ACID);
Award [2 max].
Award [1] for any characteristic up to [2 max].
Binding anything relevant (e.g. nodes, port, IP);
Associating a socket with a socket address;
Associated with the IP address and a port number for the local node;
IP address;
Port number;
Sending/receiving data (packets);
Node-to-node communication;
Works at OSI levels 3, 4, and 5 (Accept any from L3 - Network, L4 - Transport, L5 - Session);
