# Study on Effective Temporal Data Retrieval Leveraging Complex Indexed Architecture
## 5 Data Retrieval
### Proposed Select Statement Definition
**Spatial_positions (_polymon_def_)**  
**Spatial_positions (latitude_val, longitude_val, radius_val)**  
**Spatial_positions (_region_def_)**  
Definition of the region can be done for the whole database, user, or table association. **Create region_representation _name_ defined as (_definition!polynom_);**  
For the evaluation, the precision level can be specified holding the following options:  
Precision_level:  
1. only measured data,
2. measured and calculated (estimated) data,
3. fuzzy classification of the assignment defined by the function. Another relevant factor is delimited by the time duration (time_assignment), during which the object was part of the defined region, polygon, or point with radius delimitation, respectively. This clause can be extended by the optional parameter dealing with the time duration using Interval data type--Interval Day to Second (syntax is shown in Figure 15) or Interval Year to Month (syntax shown in Figure 16) [39]:The complex definition of the Spatial_positions clause is defined by the following structure. Note, that the data assignment to the defined region is different from the event_definition clause, in principle. In this case, namely, assignment granularity is used with the reflection to the spatial positions, whereas the event_definition deals with the whole time range of the data to be obtained:  
**Spatial_positions(spatial_data_bordering [precision_level, time_assignment])**  
* **Transaction_reliability**  
The purpose of the Transaction_reliability clause is to manage and retrieve individual versions of object states over time. The required architecture is bi-temporal, resp. a multi-temporal system that allows you to define, modify, and correct existing states using transactional validity. So it is not only the validity itself that is monitored, the emphasis is also on the versions and later data corrections. In principle, any change to an existing situation must result in the termination of its transactional validity. The new transaction validity is expressed by the transaction itself, its beginning is identical with the beginning of the transaction, the end of validity is unlimited because it is assumed that the inserted state is correct--we do not consider its correction at the time. The transaction validity uses the so-called historical temporal system, from the point of view of transactions, it is possible to work only with the current validity and validity in the past (historical versions of states that were later changed). From a logical point of view, it is not important to define a change in the reliability of the state in the future (detected changes and version corrections must be applied immediately). Because states can be corrected, the Select command must have the option to delimit the specific version that the user wants to obtain. The proposed Transaction_reliability clause addresses the issue of versions concerning transaction time. Either a time point, time interval, or period can be defined. **Transaction_rel_timepoint(t)**  
**Transaction_rel_interval(t1, t2, [CC|CO])**  
**Transaction_rel_interval(period_def)**  
Time frame principles remain the same as defined for event_definition clause, however, the processed time frame is not valid, but the transaction reliability or transaction definition perspective, respectively. * **Model_reflection**  
When dealing with the data modeling over time, the particular data model can be changed, individual constraints can be added, edited, or terminated, as well as the data structure and individual attribute set can evolve. To cover the data model definition, based on the problem specification and solution proposal in this paper, we introduce the following options. Model_reflection clause can hold either value AS-WAS, which forces the data result set to cover the conditions, as they existed in the time of the particular object state validity, which can be, however, later changed.