A data table definition defines a set of records stored on the Client. Each record consists of two fields containing a key and value. A data table is intended to contain a small number of records (less than 100) that may be displayed to users in drop-down lists and other uses. A data table is defined at the application level and is available to all modules of the application. Its structure also defines how its data is synchronized.
The intended purpose of a data table is to provide short lists of records that can be created quickly and with little overhead related to maintaining the data. A data table has no built-in search support and if searching is necessary it is performed row-by-row (e.g., no binary or other search algorithms are employed).
As a part of its definition, the data table contains the components to synchronize data. This includes determining if new data is needed for the table as well as the processes to retrieve the records for the data table. The definition of a data table requires the selection of an existing system connection. The type of synchronization components a data table contains is based on the type of the selected system connection.
Though the synchronization components will differ in form and structure related to the type of back end system for which they are intended, they are required to always return two general categories of data to the Agentry Server. The first is a date and time value retrieved from the back end that indicates the last time when the data source for the data table was last modified in the back end system. The second is the actual data for the data table’s records.
The date and time value is compared to a date and time value stored internally on the Agentry Client for each data table instance. This internal value is called the data table’s last update value. This last update value indicates when the data table was downloaded to the Agentry Client. When the date and time retrieved from the back end is newer than the Agentry Client’s last update value for the data table it is the indication that the records for the data table must be retrieved. The existing records on the Agentry Client will be deleted and replaced with the new data retrieved for the data table. This is an all-or-none operation and individual records cannot be selectively replaced.
The specifics of how the date and time values for the data tables are retrieved, and how the records are retrieved for the data table are provided in the discussions specific to each of the possible system connection types that may be selected for the data table definition when initially defined.