Clicking on the Cache View checkbox will enable Caching on a Dataset. Once ticked a number of other controls will become visible. To turn on in-memory caching, the only values that must be provided are the tick in this box and a Timeout Period which specifies the number of minutes that the data should be held in memory for. The Schedule Service will refresh the cache at the end of this time period.
The Dataset will need to be saved to enable the “Refresh Cache” button which can then be clicked to cache a copy of the data in-memory on the Nathean Analytics Server..
Some of the controls displayed will be dealt with in later sections of this chapter. For in-memory caching, the relevant fields are:
|Last Refresh||The date and time of the last successful cache of the Dataset|
|Timeout Period||The number of minutes that the data should be held in memory for before the Schedule Service attempts a refresh of the data|
|Scheduler Status||The result of the Schedule Service’s last attempt to cache this Dataset|
|Cache View||Check this box to turn on caching of the Dataset and reveal the Cache Properties|
|Refresh Cache||Forces a refresh of the Cache|
|Generate Cache Query||Creates a LINQ query in the “Cache Query” window below that can be modified to form the basis of another Dataset that retrieves fields from the in-memroy cache of this dataset|
|Cache Start||The time at which caching of the Dataset should begin.|
|Cache End Time||The time at which caching of the Dataset should end.|
|Cache Threshold||The number of minutes that in-memory Data Tables should be held for after the Timeout Period. Use this for long running queries to ensure that views on the dataset will still return the older copy of the cache while the new copy is being generated.|
|Use direct SQL in Logix Professional||Allows the Nathean Analytics Desktop tool to query the data connector directly, bypassing the in-memory cache|
|Use Server Mode|