Hi,
The only thing that could slow you down is that the genAttrib array will take
more and more memory as the result set grows. I would recommend you to create
a function that uses the mysql row directly instead of creating this huge
array.
something like
while ((row = mysql_num_rows(result))){
usedata(row);
}
Of course it depends on what do you need the mysql data for - but if you can
make it to use one row at a time it should run a lot more faster.
--
Dobromir Velev
dobromir@stripped
http://www.websitepulse.com/
On Tuesday 29 June 2004 08:50, Matt Eaton wrote:
> Hi all,
>
> I was hoping this was the right place for a question about the C API.
> I've been grabbing result sets from tables in the C API for a few years
> now, but I'm starting to work with result sets that are big enough to
> bog me down. Of course, the result sets aren't insanely big, so I was
> wondering why it was taking so long for me to suck them in to C,
> especially when I can run the same query from the command line using the
> binaries and they can cache it to a file on the hard disk pretty much
> instantly. So, basically, I was just hoping that I've been doing
> something wrong, or at least that there was something I could do better,
> to make my database communication as fast as the mysql command line
> tools. I've checked out their source and nothing obvious jumps out at
> me. Here's a non-functional sample of my code:
>
> int main(int argc, char *argv[] ) {
> int uid;
> int sid;
> char sqlBuff[4000];
> int err = 0;
> int i;
> // Setup the database communications space:
> MYSQL dbase;
> MYSQL_RES *result;
> MYSQL_ROW row;
>
> float **genAttrib;
>
> //... snip ...
>
>
> // Connect to the database:
> if (mysql_init(&dbase) == NULL) err = 1;
> else {
>
>
> if(mysql_real_connect(&dbase,"localhost","login","pass","test",0,NULL,CL
> IENT_FOUND_ROWS) == NULL) {
> err = 1;
> fprintf(stderr, "Failed to connect to database:
> Error: %s\n",
> mysql_error(&dbase));
> }
> }
>
> // If the connection couldn't be established:
> if(err) {
> printf("db connection failed!\n");
> exit(1);
> }
>
>
> //... snip ...
>
> // This query could have as many as a million rows returned, but
> the query itself runs quite fast. It seems to just be
> // sucking it into C that can take up to four seconds on our
> dual Xeon server.
> sprintf(sqlBuff,"SELECT A.* FROM `attribs` as A, login AS L
> WHERE A.guid=L.guid AND L.isActive=1 AND L.sid=%d AND
> A.guid!=%d",sid,uid);
> if (mysql_real_query(&dbase,sqlBuff,strlen(sqlBuff))) {
> printf("Pool Attributes Select Failed... dumbass\n");
> fprintf(stderr, "Error: %s\n",
> mysql_error(&dbase));
> exit(1);
> }
>
> result = mysql_store_result(&dbase);
> numRows=mysql_num_rows(result);
> for (i=0;i<numRows;i++) {
> row = mysql_fetch_row(result);
> tempq=atoi(row[1]);
> tempP=atoi(row[0]);
> genAttrib[tempP][tempq]=atoi(row[2]);
> }
>
> return 0;
> }
>
> So, if someone sees something that I could change to speed things up, or
> I should direct this question elsewhere... thanks for your help and
> thanks for reading this far!
>
> Thanks again,
> Matt
