ad hoc query
Ad-hoc evaluations are evaluations compiled directly and interactively by the user. They differ from prefabricated evaluations in that the user can determine the content and appearance of the evaluation himself. An important prerequisite for ad hoc evaluations is online access to a database. This is usually a datamart, e.g. an OLAP cube or a datamart database.
"Ad hoc" comes from Latin and means, mutatis mutandis, "made for this moment" or "for this purpose". Ad hoc evaluations are accordingly evaluations that are created out of a specific situation. They supplement the standard evaluations (also called prefabricated evaluations), which cover the frequently occurring evaluation requirements. For ad-hoc evaluations, business intelligence platforms usually provide their own tools. These can be oriented as analysis (OLAP) tools or reporting tools.
In contrast to the prefabricated evaluation, whose structure, appearance and selection options are predefined by the creator, the end user has all the design options in his own hands within the prepared framework (metadata structure). It should be noted here that ad hoc evaluation tools have a limited range of functions compared to evaluation tools for specialized authors. This is intended to enable even non-experts to quickly create their own evaluations. Typical work steps for creating an ad hoc evaluation are:
- Specifying the data fields to be displayed,
- Setting filters,
- Determining sorting,
- Specifying layout elements such as column headers, titles, page format, etc.
The main advantage of ad-hoc evaluations is the possibility to quickly compile information that is not displayed in the predefined evaluations. For example, details can be explored or special requests can be fulfilled without much effort.
The main disadvantage is that the user needs very good knowledge of the data and that under certain circumstances very high demands are made on the performance of the system. For these reasons, the use of ad hoc evaluations is usually reserved for small teams of specialists, e.g. in controlling or marketing.