The rows in a table are divided into columns. Each column has a name and data type.
SESAM/SQL distinguishes between atomic and multiple columns.
In an atomic column, exactly one value can be stored in each row.
In a multiple column, several values of the same type can be stored in each row. A multiple column is made up of a number of column elements. In the case of a single column, a single value is stored for each row. The value of a column element is called an occurrence. The value of a multiple column is called an aggregate. An aggregate is made up of the occurrences of the individual column elements.
A column element is referenced within the multiple column using its position number. Contiguous subareas of a multiple column are specified using the position numbers of the first and last column elements in the subarea.
Example
X[2] or X(2)
Second column element of the multiple column X
X[4..7] or X(4..7)
Subarea consisting of column elements 4, 5, 6, and 7 of the multiple column X