Re: Which strategy is better to traverse a big table?

[yanlin peng]

Thanks to khan and James. Starting from your comments, I investigate
mysql C API and found that mysql_store_result (that I used in my codes)
does not deliver results piecemeal, instead it delivers the whole results
at once.

Another function mysql_use_result(), however, can handle big results
more efficiently. It initiates a row-by-row result set retrieval. In my
case, I'll select all qualified rows and use this function to process
the result row by row.

NOTE: mysql_use_result() may have deadlock problem, as mentioned in the manual:
"you shouldn't use mysql_use_result() if you are doing a lot of processing for
each row on the client side, or if the output is sent to a screen on which the
user may type a ^S (stop scroll). This ties up the server and prevent other
threads from updating any tables from which the data is being fetched. "

Thanks again for your help. I found this forum is very active and helpful!