What are the respective effects of the ;NOWAIT (the default) and ;WAIT directives in the context of a remote COPY command within a READ loop ?
Let us consider the following abbreviated example : read row = localdb.emp setvar rec_emp.ename = ename copy rec_emp to remotedb.emp endread In this example, the COPY statement to a remote database remotedb is NOWAITed (the default) : Warehouse will continue to process the script, reading from localdb and inserting toremotedb, without waiting for a response from the remote Warehouse server for each remote operation. This is a significant performance optimization as operations are interleaved. NOWAIT has implications when used inside a TRY/RECOVER block. Should an error occur during a NOWAITed COPY, the RECOVER statement would not be entered with the record that had the error. On the other hand, if the COPY statement were coded as follows : copy rec_emp to remotedb.emp; wait Warehouse would wait until the remote COPY operation completed before reading the next row from the source. Should an error occur during a WAITed COPY, RECOVER would be entered with the specific record that had the
Related Questions
- What are the respective effects of the ;NOWAIT (the default) and ;WAIT directives in the context of a remote COPY command within a READ loop ?
- How do I use the Linux screen command for running applications or commands from a remote session?
- What if I copy plot files to my plotter through a command prompt? Will Sepialine track that?
