RE: Change Data Capture API
Posted in 2011
IDS 11.50.FC5 to 11.70.FC4 I am beginning to work with the Change Data Capture ESQL/C API provided by Informix, and I have a list of questions with no where to turn. All my questions will have their origination with the sample program provided by Informix; however, general reponses will be helpful too. 1) First, an overall explanation of how this works would be helpful. When you start a capture session, and name the tables for which you would like to capture data, is the actual data stored in a table in the syscdc database until you read it, or do you need to keep a concurrent read session going to read the data as it is captured and immediately do whatever you want to do with the data? 2) If the data is stored in the syscdc database.sometable, does the data get automatically deleted after it has been read by the read function? 3) Once I run cdc_opensess() and cdc_startcapture(), do I have to loop infinitely in my read program as long as I want to capture data, or can I run the program on a regular basis, say hourly, to read data? 4) If I run the program hourly, I assume it is extracting data from the logs, does it automatically know where to start in which log from information stored in the syscdc database tables? 5) Relating to capturing data, if I were to want to run the program on an hourly basis, would I need to call cdc_opensess() and cdc_startcapture() every time the program runs; and will it start in the log file where I left off previously with the next record? I have more questions, but this will get me started. I didn't think the documentation was as specific in explanation as I need. I wasn't sure, as well, if the captured data was actually stored in a table in the syscdc database, or if the data only existed when the log was read while my program is running. Thank you for your indulgence and patience. Larry