| Schema | The logical organization of data in a database. |
| Scope of Integration | the formal definition of the boundaries of the system being modelled. |
| Sequential File | a file in which records are ordered according to the values of one or more key fields. |
| Serial File | a sequential file in which records are physically adjacent, in sequential order. |
| Slowly Changing Dimensions | The approaches involving maintaining a list or history by adding related rows or new columns, or simply ignoring the problem by retaining the only the current data.Type I, Type II, Type III |
| Snowflake Schema | A snowflake schema is a set of tables comprised of a single, central fact table surrounded by normalized dimension hierarchies. Each dimension level is represented in a table. Snowflake schema implement dimensional data structures with fully normalized dimensions. Star schema are an alternative to snowflake schema. |
| Star Schema | A star schema is a set of tables comprised of a single, central fact table surrounded by de-normalized dimensions. Each dimension is represented in a single table. Star schema implement dimensional data structures with de-normalized dimensions. Snowflake schema are an alternative to star schema. |
| Surrogate Key | It has system-generated artificial primary key values, which allows to maintain historical records in the Data Warehouse more effectively. |
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