Minimum retrieval

The minimum value retrieval mode returns the minimum value from the actual data values within a retrieval cycle. If there are no actual data points stored on the historian for a given cycle, nothing is returned. NULL is returned if the cycle contains one or more NULL values.

As in cyclic retrieval, the number of cycles is based on the specified resolution or cycle count. However, minimum retrieval is not a true cyclic mode. Apart from the initial value, all points returned are delta points.

Minimum retrieval only works with analog tags. For all other tags, normal delta results are returned.

All returned values are in chronological order. If multiple points are to be returned for a particular timestamp, they are returned in the order in which the tags were specified in the query. If the minimum value occurs several times in a cycle, the minimum value with the earliest timestamp is returned.

The minimum retrieval mode must use the "<=" operator for the ending date/time.

Using the minimum retrieval mode with a cycle count of 1 returns the same results as the SQL Server MIN aggregate; however, the data is returned much faster.