# A Spatio-Temporal Building Exposure Database and Information Life-Cycle Management Solution
## 4 Information Life-Cycle Management Solution
### Information Disposal and Archiving  
In the case of geospatial information management, information about a geographic object can be disposed and archived because (1) it is replaced with information of higher value (e.g., accuracy) or (2) the object that the information is referring to (e.g., building) has been modified or destructed in reality. In both cases, the obsolete information is disposed and archived for possible later retrieval. The difference between the two cases being that in case (1) the archived information refers to the database transaction life-cycle of the object, whereas in case (2) the archived information relates to the real-world life-cycle of the object.  
Depending on the aim of the information system, the type and duration of archiving disposed information may vary. Archived information relating to the real-world changes of an object is an essential part of the life cycle of the actual object under observation. It is not disposed because the information lost value but because the object changed or lost its existence in the real world. The information referring to this object may therefore still be of great importance for further analysis even after its disposal. On the contrary, archived information that was disposed because better information became available has, by definition, less value than the new information. Therefore, the decision on whether to archive the disposed information or not and, in this case, for how long to archive it may differ significantly from the previous case.  
In the database model, both cases of information disposal and archiving are supported. A specific PL/pgSQL (Procedural Language/PostgreSQL) function (history.history_table()) has been implemented in order to activate or deactivate the logging of database transactions and to archive  
\begin{table}
\begin{tabular}{c c c c c c c} \hline
**Attribute** & **Description** & **Source** & \begin{tabular}{c} **Value** \\ **Type** \\ \end{tabular} & \begin{tabular}{c} **Avg Value** \\ **R1** \\ \end{tabular} & \
\begin{tabular}{c} **Avg Value** \\ **R2** \\ \end{tabular} &
\begin{tabular}{c} **Avg Value** \\ **R3** \\ \end{tabular} \\ \hline HEIGHT & Height & RRVS & BP & 0.00 & 0.00 & 47.52 \\ LLRS & Lateral Load-Resisting System & RRVS & BP & 0.00 & 0.00 & 46.88 \\ MAT,PROP & Material Property & RRVS & BP & 0.00 & 0.00 & 45.58 \\ MAT\_TECH & Material Technology & RRVS & BP & 0.00 & 0.00 & 55.29 \\ MAT,TYPE & Material Type & RRVS & BP & 0.00 & 0.00 & 52.82 \\ OCCUPY & Building Occupancy Class & RRVS & BP & 0.00 & 0.00 & 46.76 \\ OCCUPY\_DT & Building Occupancy Class—Detail & RRVS & BP & 0.00 & 0.00 & 49.35 \\ THE\_GEOM & Object geometry & EO, OSM, OF & BP & 73.00 & 84.04 & 86.91 \\ YR\_BUILT & Date of Construction or Retrofit & RRVS & BP & 0.00 & 0.00 & 0.00 \\ \hline \end{tabular}
\end{table}
Table 1: Excerpt of a dynamically created meta-data summary table that summarizes the currently available attributes, their sources, and the evolution of their average value (here degree of belief in percent) from release R1 to R3.  
modifications and disposal of information. The function can be applied to specific tables or database views as a whole, or the transaction logging can be activated only for specific attributes of a table (e.g., log transactions only if attribute x is modified). If, for example, only the attributes related to the valid time of the object are activated for logging, the system would archive only the real-world change (case 2) and not the information updates (case 1).