Field | Either an attribute, or a column of attributes |
Tuple | All fields in one table associated with a single item. A "row" of a table. |
Record | See tuple. |
Relation | A set of records with identical structure. A "table". |
Metadata | A description of every table and the associated fields. |
Index | A data structure that speeds access when searching, but does not change the semantic content of the database. |
BLOB | A Binary Large Object. |
Key | A field or set of fields that is unique for each record. For example, social security number is a key for people, and birthday is not. |
Projection | To choose only certain fields of a table. |
Selection | To choose only certain records of a table. |
Join | To produce a new table that is the Cartesian product of the two tables. To "multiply" two tables. |
Scheme | A set of table descriptions that describe the database. Just like metadata but without the field types. |
Consistent | The database describes the real world as intended. |
Decomposition | To break a single table into multiple tables. |
Database | A set of tables |
Transaction | The unit of work in a database. |
Commit | Make the transaction's changes permement |
Abort | Erase the transaction's changes |
Lock | Rights to a data item that preclude other's from that data item |
Deadlock | A set of transactions that will wait forever on each other because of conflicting locks. |
SQL | The Structured Query Language |
Oracle | The most popular commercial database |
DB2 | The other most popular commercial database |
mSQL | Our database software |
Lite | The langauge we will use to access the mSQL database. |