Question on http query
Hi, I'd like to know if MySQL server supports http queries? Thanks. Kandy -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/mysql?unsub=arch...@jab.org
slow query on replication master and slave
Hi, Is it true that the performance of running a query on a live replication master and slave has to be much slower than running a query on a static server? I've tried to run the following query on a replication master and it takes 1 min 13.76 sec to finish. SELECT *, ABS(timeA-1266143632) as distance FROM tableA WHERE timeA - 1266143632 = 0 ORDER BY distance LIMIT 1; And if I run it on the replication slave, it takes 24.15 sec. But if I dump the whole database to another machine as static, it only takes 3.70 sec or even less to finish. The table has 386 columns and timeA is an index. Is there a way to improve the query or any other factors that would affect the performance? Thanks. Kandy -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/mysql?unsub=arch...@jab.org
Question on replication
Hi, Is there a replication setup method just to replicate a specific database not all the databases or exclude a specific database not to be replicated? Thank you. Kandy -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED]
C++ cache MYSQL_RES
Hi, Is there a way to cache the MYSQL_RES in C++? I've tried to develop a class with functions returning the MYSQL_RES, MYSQL_ROW and MYSQL_FIELDS. The functions work fine within the class file. But if I call the functions where else, I'll either get 'Segmentation fault' or 'bus error'. Any idea? Thank you. Kandy -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED]
Re: Need help to query with timestamp in C++
Hi Saul, I need to use C++ and I'm not writing a web application. Thanks anyway. Kandy I have done queries to the database in PHP with variables like month but easily can select from a range of time and data to produce the same results, the output goes directly to the web so if that is what you are seeking for, I can help with PHP. Saul Kandy Wong wrote: Hi, I need to write a C++ program in a Linux environment to query with a timestamp. The user will only provide with an approximate time so I'd like to know how can I write a program or a query to return the closest data. The followings are the timestamp in the MySQL database: | 2008-08-05 03:56:09 | 1217933769 | | 2008-08-05 03:56:19 | 1217933779 | | 2008-08-05 03:56:29 | 1217933789 | | 2008-08-05 03:59:39 | 1217933979 | | 2008-08-05 03:59:49 | 1217933989 | | 2008-08-05 03:59:59 | 1217933999 | | 2008-08-05 04:02:39 | 1217934159 | | 2008-08-05 04:02:49 | 1217934169 | | 2008-08-05 04:02:59 | 1217934179 | For example, '2008-08-05 04:01:39' is the time provided by the user which does not exist in the database. So, how can I return the closest data? I know I can make use of 'LIKE' but this will return more than one data. What is the best method to get the closest one? And what is the good connector (C++ to MySQL) to use? Any suggestion? Thank you. Kandy -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED] -- Kandy Wong Scientific Programmer Analyst TRIUMF (Canada's National Laboratory for Particle and Nuclear Physics) 4004 Wesbrook Mall Vancouver, BC, Canada, V6T 2A3 Phone: (604) 222- 1047 ext. 6193 Email: [EMAIL PROTECTED] -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED]
Re: Need help to query with timestamp in C++
Hi Dusan,
Thank you so much. It works!
Kandy
Hi Kandy,
this could be the query you are looking for. It should return record
with the closest timestamp to your required time:
(SELECT TIMEDIFF('20080815091907', timestamp_column) AS diff, t.* FROM
table1 t
WHERE timestamp_column = '20080815091907'
ORDER BY timestamp_column DESC LIMIT 1
)
UNION
(SELECT TIMEDIFF(timestamp_column, '20080815091907') AS diff, t.* FROM
table1 t
WHERE timestamp_column = '20080815091907'
ORDER BY timestamp_column LIMIT 1
)
ORDER BY diff LIMIT 1
HTH,
Dusan
Kandy Wong napsal(a):
Hi,
I need to write a C++ program in a Linux environment to query with a
timestamp.
The user will only provide with an approximate time so I'd like to know
how can I write a program or a query to return the closest data.
The followings are the timestamp in the MySQL database:
| 2008-08-05 03:56:09 | 1217933769 |
| 2008-08-05 03:56:19 | 1217933779 |
| 2008-08-05 03:56:29 | 1217933789 |
| 2008-08-05 03:59:39 | 1217933979 |
| 2008-08-05 03:59:49 | 1217933989 |
| 2008-08-05 03:59:59 | 1217933999 |
| 2008-08-05 04:02:39 | 1217934159 |
| 2008-08-05 04:02:49 | 1217934169 |
| 2008-08-05 04:02:59 | 1217934179 |
For example, '2008-08-05 04:01:39' is the time provided by the user
which
does not exist in the database. So, how can I return the closest data?
I
know I can make use of 'LIKE' but this will return more than one data.
What is the best method to get the closest one?
And what is the good connector (C++ to MySQL) to use?
Any suggestion?
Thank you.
Kandy
--
MySQL General Mailing List
For list archives: http://lists.mysql.com/mysql
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Need help to query with timestamp in C++
Hi, I need to write a C++ program in a Linux environment to query with a timestamp. The user will only provide with an approximate time so I'd like to know how can I write a program or a query to return the closest data. The followings are the timestamp in the MySQL database: | 2008-08-05 03:56:09 | 1217933769 | | 2008-08-05 03:56:19 | 1217933779 | | 2008-08-05 03:56:29 | 1217933789 | | 2008-08-05 03:59:39 | 1217933979 | | 2008-08-05 03:59:49 | 1217933989 | | 2008-08-05 03:59:59 | 1217933999 | | 2008-08-05 04:02:39 | 1217934159 | | 2008-08-05 04:02:49 | 1217934169 | | 2008-08-05 04:02:59 | 1217934179 | For example, '2008-08-05 04:01:39' is the time provided by the user which does not exist in the database. So, how can I return the closest data? I know I can make use of 'LIKE' but this will return more than one data. What is the best method to get the closest one? And what is the good connector (C++ to MySQL) to use? Any suggestion? Thank you. Kandy -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED]
