Re: dynamically alloc cursur vs. local,gloab cursor
Hi.
This is the wrong forum for this product. Please see
http://forums.mysql.com/list.php?144. However, I will answer your question in this reply. In the future, please use the other forum to post questions about Connector/Arduino.
1. What is the difference concerning speed and memory footprint?
The choice of using dynamic memory was explicitly for saving memory for local variables. Execution speed difference was not calculated. I am not sure if there would be any noticeable (measurable) difference or even if there are scenarios where it would matter given the limited sophistication of the hardware. You're welcome to do some experiments and report your findings.
2. Which one is preferred for above mySQL statements?
That depends. If your sketch is large or the query is large, dynamic memory is the better choice.
3. Can local, global cursors be used in at least INSERT, UPDATE and SELECT queries (I guess yes)?
No. Local only.
4. Are there any limitations for local, global cursors for other mySQL queries?
See (3).
Connector/Arduino is a bare-bones connector for MySQL. It implements only a portion of the entire suite of features in order to save space and make it feasible to run on the smaller Arduino boards. Thus, you can perform only those queries whose results fit into memory one row at a time.
Chuck