Manoj, 1. In terms of functionality to support this, there are mechanisms that provide the capability of accomplishing this type of functionality in components via ControllerServices like the [DistributedMapCacheServer][1]/Client or [DistributedSetCacheServer][2]/Client.
There are processors that make use of these controller services in manner analogous to your desired feature such as [DetectDuplicate][3] or [ListHDFS][4]. There is work under way for the next release (0.5.0) that brings more framework functionality to accomplish such tasks and its work is outlined in our [State Management Feature Proposal][5]. 2. ExecuteSQL does not currently perform PreparedStatements for retrieval, but PutSQL is using them. Is your desired usage tending toward the ExecuteSQL processor being a source processor where it is continuously running the same statement using an updated timestamp value as mentioned in your first point? [1]: http://nifi.apache.org/docs/nifi-docs/components/org.apache.nifi.distributed.cache.server.map.DistributedMapCacheServer/index.html [2]: http://nifi.apache.org/docs/nifi-docs/components/org.apache.nifi.distributed.cache.server.DistributedSetCacheServer/index.html [3]: http://nifi.apache.org/docs/nifi-docs/components/org.apache.nifi.processors.standard.DetectDuplicate/index.html [4]: http://nifi.apache.org/docs/nifi-docs/components/org.apache.nifi.processors.hadoop.ListHDFS/index.html [5]: https://cwiki.apache.org/confluence/display/NIFI/State+Management On Mon, Jan 4, 2016 at 6:49 AM, Kalikodan-Veetil, Manoj K < [email protected]> wrote: > Hello, > > Looking for some guidance. > > > 1. Is there a way today in Nifi, where I can save some persistent > data and retrieve later. Use-case I am looking at is to query a table for > latest updates. I wanted to save the last datetime till which data was > pulled & use that as start-datetime for next pull. > > 2. Today doe NiFi provide any way to do prepare statements in SQL > query, to make repetitive queries more efficient? > Thanks > Manoj >
