Installation for managing a database having: a/ a database comprising: a1/ means for filtering the data contained in fields using internal algorithms for optimising the database which are capable of providing the data sought in response to a query defining the filter; and a2/ at least one data hierarchy of at least three hierarchical levels; and b/ interrogation means capable of providing at least one query defining a filter permitting the selection of the data sought by using the filtering means; characterised in that said installation has means for representing a hierarchy table comprising, for each hierarchised datum: all of the data on which said hierarchised datum is dependent, regardless of the number of hierarchical levels separating them, each of the data on which said hierarchised datum is dependent being contained in a separate record of the table, said record further containing the hierarchised datum; and an indicator of the degree of relationship representing the distance between the hierarchical level of said hierarchised datum and the level of each hierarchised datum on which said hierarchised datum is dependent and an indicator of the level of hierarchical depth representing the distance between the said hierarchical level of the hierarchised datum and the highest level of the hierarchised data on which said hierarchised datum is dependent, and in that, during an interrogation on the basis of a query pertaining to hierarchised data and defining a filter comprising the indicator of the degree of relationship and/or indicator of the level of hierarchical depth, the filtering means of the database are suitable for providing a response to the query formulated on the basis of the hierarchy table without resorting to tools for the multidimensional interrogation of the database that are external to the database. a/ a database comprising: a1/ means for filtering the data contained in fields using internal algorithms for optimising the database which are capable of providing the data sought in response to a query defining the filter; and a2/ at least one data hierarchy of at least three hierarchical levels; and a1/ means for filtering the data contained in fields using internal algorithms for optimising the database which are capable of providing the data sought in response to a query defining the filter; and a2/ at least one data hierarchy of at least three hierarchical levels; and b/ interrogation means capable of providing at least one query defining a filter permitting the selection of the data sought by using the filtering means; characterised in that said installation has means for representing a hierarchy table comprising, for each hierarchised datum: all of the data on which said hierarchised datum is dependent, regardless of the number of hierarchical levels separating them, each of the data on which said hierarchised datum is dependent being contained in a separate record of the table, said record further containing the hierarchised datum; and an indicator of the degree of relationship representing the distance between the hierarchical level of said hierarchised datum and the level of each hierarchised datum on which said hierarchised datum is dependent and an indicator of the level of hierarchical depth representing the distance between the said hierarchical level of the hierarchised datum and the highest level of the hierarchised data on which said hierarchised datum is dependent, and in that, during an interrogation on the basis of a query pertaining to hierarchised data and defining a filter comprising the indicator of the degree of relationship and/or indicator of the level of hierarchical depth, the filtering means of the database are suitable for providing a response to the query formulated on the basis of the hierarchy table without resorting to tools for the multidimensional interrogation of the database that are external to the database. all of the data on which said hierarchised datum is dependent, regardless of the number of hierarchical levels separating them, each of the data on which said hierarchised datum is dependent being contained in a separate record of the table, said record further containing the hierarchised datum; and an indicator of the degree of relationship representing the distance between the hierarchical level of said hierarchised datum and the level of each hierarchised datum on which said hierarchised datum is dependent and an indicator of the level of hierarchical depth representing the distance between the said hierarchical level of the hierarchised datum and the highest level of the hierarchised data on which said hierarchised datum is dependent, and in that, during an interrogation on the basis of a query pertaining to hierarchised data and defining a filter comprising the indicator of the degree of relationship and/or indicator of the level of hierarchical depth, the filtering means of the database are suitable for providing a response to the query formulated on the basis of the hierarchy table without resorting to tools for the multidimensional interrogation of the database that are external to the database.