Load Snapshots in a Named Variable
This query creates a variable, named coffee, to stream the selected snapshots and then use in further RAQL queries. The snapshot query retrieves all snapshots for a single mashable, the sample Yahoo local search mashable identified by ID:
Once the dataset has been loaded, the RAQL query can act on the dataset or it can be stored in the Presto Analytics In-Memory Stores.
The full EMML for this sample is:
<mashup name="coffeeSnaps"
xmlns="http://www.openmashup.org/schemas/v1.0/EMML"
xmlns:macro="http://www.openmashup.org/schemas/v1.0/EMMLMacro"
xmlns:presto="http://www.jackbe.com/v1.0/EMMLPrestoExtensions"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.openmashup.org/schemas/v1.0/EMML/../schemas/EMMLPrestoSpec.xsd">
<operation name="Invoke">
<output name="result" type="document"/>
<snapshot name="coffee" query="select * from snapshots where service='YahooLocalSearchREST' "/>
<raql outputvariable="result">
select Title,Address,City,State,Latitude,Longitude,Distance
from coffee limit 60
</raql>
</operation>
</mashup>
