mysql_use_result issue: useless iterating over unused results
Hello list,
I am having this issue with mysql_use_result: it seems it will iterate
over all unused results if I call 'mysql_free_result'. The following
code illustrates this:
mysql_query(mysql,SELECT * FROM a_very_large_table);
res = mysql_use_result(mysql);
i = 0;
while (row = mysql_fetch_row(res)) {
fprintf(stderr,%d,%d\n, row[0], row[1]);
if (++i 5)
break;
}
fprintf(stderr,freeing...\n);
mysql_free_result(res);
/* wait wait wait wait wait wait wait wait ... */
With 'mysql_store_results', the code would run out of memory, because
the table is very large (20m rows). But this version will run up to 2
minutes, taking all CPU cycles with it, just freeing the result.
Is this normal behaviour or can I change something for the better?
I am using mysql 4.0.22 client and server on Linux 2.6.
Thanks!
Renald
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mysql_use_result issue: useless iterating over unused results
Hello list,
I am having this issue with mysql_use_result: it seems it will iterate
over all unused results if I call 'mysql_free_result'. The following
code illustrates this:
mysql_query(mysql,SELECT * FROM a_very_large_table);
res = mysql_use_result(mysql);
i = 0;
while (row = mysql_fetch_row(res)) {
fprintf(stderr,%d,%d\n, row[0], row[1]);
if (++i 5)
break;
}
fprintf(stderr,freeing...\n);
mysql_free_result(res);
/* wait wait wait wait wait wait wait wait ... */
With 'mysql_store_results', the code would run out of memory, because
the table is very large (20m rows). But this version will run up to 2
minutes, taking all CPU cycles with it, just freeing the result.
Is this normal behaviour or can I change something for the better?
I am using mysql 4.0.22 client and server on Linux 2.6.
Thanks!
Renald
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MySQL General Mailing List
For list archives: http://lists.mysql.com/mysql
To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED]
Re: mysql_use_result issue: useless iterating over unused results
Yup.
This is a normal behaviour. mysql_free_result() will
result in bringing each unasked rows to the client and
freeing it up row by row.
BTW, why do you need to do - select * from
Karam
--- Renald Buter [EMAIL PROTECTED] wrote:
Hello list,
I am having this issue with mysql_use_result: it
seems it will iterate
over all unused results if I call
'mysql_free_result'. The following
code illustrates this:
mysql_query(mysql,SELECT * FROM
a_very_large_table);
res = mysql_use_result(mysql);
i = 0;
while (row = mysql_fetch_row(res)) {
fprintf(stderr,%d,%d\n, row[0], row[1]);
if (++i 5)
break;
}
fprintf(stderr,freeing...\n);
mysql_free_result(res);
/* wait wait wait wait wait wait wait wait ... */
With 'mysql_store_results', the code would run out
of memory, because
the table is very large (20m rows). But this version
will run up to 2
minutes, taking all CPU cycles with it, just
freeing the result.
Is this normal behaviour or can I change something
for the better?
I am using mysql 4.0.22 client and server on Linux
2.6.
Thanks!
Renald
--
MySQL General Mailing List
For list archives: http://lists.mysql.com/mysql
To unsubscribe:
http://lists.mysql.com/[EMAIL PROTECTED]
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Re: mysql_use_result issue: useless iterating over unused results
On 01:55 Tue 11 Jan , Karam Chand wrote: Yup. This is a normal behaviour. mysql_free_result() will result in bringing each unasked rows to the client and freeing it up row by row. This sounds to me as a useless feature. What could be the reason for such wasting behaviour? BTW, why do you need to do - select * from I need to visit every row. Originally, this came up when debugging my code, and since then I added a LIMIT statement when doing so. But it still find these kinds of things annoying and unsatisfiying from an engineering point of view --- and I was just curious if it was *me* who did something wrong. But thanks for the answer! Regards, Renald -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED]
Re: mysql_use_result issue: useless iterating over unused results
I am not sure why they are doing it. You need to hack the protocol to understand it. Maybe some MySQL/network GURU will be able to help yuo. Regards, Karam --- Renald Buter [EMAIL PROTECTED] wrote: On 01:55 Tue 11 Jan , Karam Chand wrote: Yup. This is a normal behaviour. mysql_free_result() will result in bringing each unasked rows to the client and freeing it up row by row. This sounds to me as a useless feature. What could be the reason for such wasting behaviour? BTW, why do you need to do - select * from I need to visit every row. Originally, this came up when debugging my code, and since then I added a LIMIT statement when doing so. But it still find these kinds of things annoying and unsatisfiying from an engineering point of view --- and I was just curious if it was *me* who did something wrong. But thanks for the answer! Regards, Renald -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED] __ Do you Yahoo!? All your favorites on one personal page Try My Yahoo! http://my.yahoo.com -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED]
