About Chain Extracts

ChainExtract functionality allows to execute different extracts in one sequence (chain). Q and T streams are processed one-by-one:

Processing Details

While processing, this functionality does not use any auxiliary EJM streams like executing task_reporter, execwkfl etc.

Execution has the following structure:

1). Control message stream processes initial RTR.
2). Task reporter stream sends the ACK message.
3). Q stream of the first feed type extract in chain.
4). T stream of the first feed type extract in chain (if Q stream returns NO_DATA then T stream will not be started).
5). Q stream of the second feed type extract in chain.
6). T stream of the second feed type extract in chain (if Q stream returns NO_DATA then T stream will not be started).
[…]
N). Q stream of the last feed type extract in the chain.
N+1). T stream of the last feed type extract in the chain (if Q stream returns NO_DATA then T stream will not be started).
N+2). Task reporter stream sends the TSR message.

This logic improves total performance of executing several extracts of different feed types.