Abstract: A data store may implement on-demand data schema modifications. Request to change a schema for a data set in a data store may be received and a description of the change recorded as part of a schema history for the data set. The request to change the schema may then be acknowledged. When access requests directed to the data set are received at the data store, the schema history for the data set may be evaluated. If the schema history indicates that data that is to be accessed in order to service the data store needs to include one or more changes in the schema history, then a version of the schema that includes the one or more changes may be applied to the data.

Abstract: A storage engine may selectively maintain a spatial index for accessing spatial data. A spatial query may be received and the portions of the spatial index to evaluate may be determined by replacing those portions associated with regions identified for the query that do not exist in the spatial index with portions that do exist in the spatial index and are associated with a region that includes the identified regions. When inserting spatial objects into the spatial index, a determination may be made whether to create a new portion in the index if none currently exist that match a spatial index value for a new spatial object or to modify the spatial index value of the spatial object to insert the spatial object into an existing portion of the spatial index.

Abstract: In an embodiment, a method comprises processing an input data stream as the data stream is streamed and producing a derived stream therefrom; storing the input data stream in an input archive; suspending processing of the input data stream; subsequent to suspending processing, resuming processing of the input data stream, wherein resuming comprises: storing newly received data in the input data stream in a buffer, as the input data stream is streamed; determining a first timestamp; determining a second timestamp; searching the input archive to find a data item that matches the first timestamp of the last processed data item; processing data in the input archive having timestamps that are greater than the first timestamp until arriving at data with a third timestamp that is greater than the second timestamp; processing the input data stream from the buffer; continuing processing the input data stream as the input stream is streamed.

Abstract: In an embodiment, a method comprises processing an input data stream as the data stream is streamed and producing a derived stream therefrom; storing the input data stream in an input archive; suspending processing of the input data stream; subsequent to suspending processing, resuming processing of the input data stream, wherein resuming comprises: storing newly received data in the input data stream in a buffer, as the input data stream is streamed; determining a first timestamp; determining a second timestamp; searching the input archive to find a data item that matches the first timestamp of the last processed data item; processing data in the input archive having timestamps that are greater than the first timestamp until arriving at data with a third timestamp that is greater than the second timestamp; processing the input data stream from the buffer; continuing processing the input data stream as the input stream is streamed.