RE: Impossible WHERE in explain
The key_len column indicates the length of the key that MySQL decided to use. The length is NULL if the key column says NULL. Note that the value of key_len allows you to determine how many parts of a multiple-part key MySQL will actually use. i do not know the definition of parameter 'ken_len'Martin __ Disclaimer and confidentiality note Everything in this e-mail and any attachments relates to the official business of Sender. This transmission is of a confidential nature and Sender does not endorse distribution to any party other than intended recipient. Sender does not necessarily endorse content contained within this transmission. > Date: Tue, 2 Sep 2008 02:05:00 +0530> From: [EMAIL PROTECTED]> To: [EMAIL PROTECTED]> Subject: Re: Impossible WHERE in explain> CC: mysql@lists.mysql.com> > I have already tried. It's not working.> > On Tue, Sep 2, 2008 at 1:55 AM, Brent Baisley <[EMAIL PROTECTED]> wrote:> > > It might be because you you are comparing user_id to a string, when the> > field type is a decimal. Drop the quotes around the user_id search value and> > see if that works.> >> > Brent Baisley> >> >> > On Sep 1, 2008, at 3:59 PM, Krishna Chandra Prajapati wrote:> >> > Hi,> >>> >> In the query below explain gives 'Impossible WHERE noticed after'. what> >> does> >> this mean.> >>> >> CREATE TABLE `user_cookie` (> >> `user_id` decimal(22,0) NOT NULL default '0',> >> `param` varchar(128) NOT NULL default '',> >> `value` varchar(128) default NULL,> >> PRIMARY KEY (`user_id`,`param`),> >> CONSTRAINT `fk_user_cookie` FOREIGN KEY (`user_id`) REFERENCES> >> `user_info` (`user_id`) ON DELETE NO ACTION ON UPDATE NO ACTION> >> ) ENGINE=InnoDB DEFAULT CHARSET=latin1> >>> >> SELECT VALUE FROM user_cookie WHERE USER_ID = '10538485' AND PARAM => >> 'TIMEOUT' table |type |possible_keys |key | ken_len|ref | rows| 1> >> |SIMPLE | | | | | |Impossible WHERE noticed afte> >> --> >> Krishna Chandra Prajapati> >>> >> >> > > -- > Krishna Chandra Prajapati _ Be the filmmaker you always wanted to be—learn how to burn a DVD with Windows®. http://clk.atdmt.com/MRT/go/108588797/direct/01/
Re: Impossible WHERE in explain
I just tried this. I got the same results *until* I inserted a record that met the criteria. SInce the values are for a primary key, EXPLAIN could see there was no such entry and so reported that. If you actually execute the command, you would not see an error, just no rows returned. EXPLAIN was showing you that, since it can tell there are no records to retrieve, it won't try. I assume you did not actually have that data in the table. Is that right? On Mon, Sep 1, 2008 at 2:59 PM, Krishna Chandra Prajapati < [EMAIL PROTECTED]> wrote: > Hi, > > In the query below explain gives 'Impossible WHERE noticed after'. what > does > this mean. > > CREATE TABLE `user_cookie` ( > `user_id` decimal(22,0) NOT NULL default '0', > `param` varchar(128) NOT NULL default '', > `value` varchar(128) default NULL, > PRIMARY KEY (`user_id`,`param`), >CONSTRAINT `fk_user_cookie` FOREIGN KEY (`user_id`) REFERENCES > `user_info` (`user_id`) ON DELETE NO ACTION ON UPDATE NO ACTION > ) ENGINE=InnoDB DEFAULT CHARSET=latin1 > > SELECT VALUE FROM user_cookie WHERE USER_ID = '10538485' AND PARAM = > 'TIMEOUT'table |type |possible_keys |key | ken_len|ref | rows| 1 > |SIMPLE | | | | | |Impossible WHERE noticed afte > -- > Krishna Chandra Prajapati > -- Jim Lyons Web developer / Database administrator http://www.weblyons.com
Re: Impossible WHERE in explain
I have already tried. It's not working. On Tue, Sep 2, 2008 at 1:55 AM, Brent Baisley <[EMAIL PROTECTED]> wrote: > It might be because you you are comparing user_id to a string, when the > field type is a decimal. Drop the quotes around the user_id search value and > see if that works. > > Brent Baisley > > > On Sep 1, 2008, at 3:59 PM, Krishna Chandra Prajapati wrote: > > Hi, >> >> In the query below explain gives 'Impossible WHERE noticed after'. what >> does >> this mean. >> >> CREATE TABLE `user_cookie` ( >> `user_id` decimal(22,0) NOT NULL default '0', >> `param` varchar(128) NOT NULL default '', >> `value` varchar(128) default NULL, >> PRIMARY KEY (`user_id`,`param`), >> CONSTRAINT `fk_user_cookie` FOREIGN KEY (`user_id`) REFERENCES >> `user_info` (`user_id`) ON DELETE NO ACTION ON UPDATE NO ACTION >> ) ENGINE=InnoDB DEFAULT CHARSET=latin1 >> >> SELECT VALUE FROM user_cookie WHERE USER_ID = '10538485' AND PARAM = >> 'TIMEOUT'table |type |possible_keys |key | ken_len|ref | rows| 1 >> |SIMPLE | | | | | |Impossible WHERE noticed afte >> -- >> Krishna Chandra Prajapati >> > > -- Krishna Chandra Prajapati
Re: Impossible WHERE in explain
It might be because you you are comparing user_id to a string, when the field type is a decimal. Drop the quotes around the user_id search value and see if that works. Brent Baisley On Sep 1, 2008, at 3:59 PM, Krishna Chandra Prajapati wrote: Hi, In the query below explain gives 'Impossible WHERE noticed after'. what does this mean. CREATE TABLE `user_cookie` ( `user_id` decimal(22,0) NOT NULL default '0', `param` varchar(128) NOT NULL default '', `value` varchar(128) default NULL, PRIMARY KEY (`user_id`,`param`), CONSTRAINT `fk_user_cookie` FOREIGN KEY (`user_id`) REFERENCES `user_info` (`user_id`) ON DELETE NO ACTION ON UPDATE NO ACTION ) ENGINE=InnoDB DEFAULT CHARSET=latin1 SELECT VALUE FROM user_cookie WHERE USER_ID = '10538485' AND PARAM = 'TIMEOUT'table |type |possible_keys |key | ken_len|ref | rows| 1 |SIMPLE | | | | | |Impossible WHERE noticed afte -- Krishna Chandra Prajapati -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED]
Impossible WHERE in explain
Hi, In the query below explain gives 'Impossible WHERE noticed after'. what does this mean. CREATE TABLE `user_cookie` ( `user_id` decimal(22,0) NOT NULL default '0', `param` varchar(128) NOT NULL default '', `value` varchar(128) default NULL, PRIMARY KEY (`user_id`,`param`), CONSTRAINT `fk_user_cookie` FOREIGN KEY (`user_id`) REFERENCES `user_info` (`user_id`) ON DELETE NO ACTION ON UPDATE NO ACTION ) ENGINE=InnoDB DEFAULT CHARSET=latin1 SELECT VALUE FROM user_cookie WHERE USER_ID = '10538485' AND PARAM = 'TIMEOUT'table |type |possible_keys |key | ken_len|ref | rows| 1 |SIMPLE | | | | | |Impossible WHERE noticed afte -- Krishna Chandra Prajapati
Re: sync
yes, they should be identical , am thinking to use the howtoforge mysql_database_replication document. On Mon, Sep 1, 2008 at 4:58 PM, Ranjeet Walunj <[EMAIL PROTECTED]>wrote: > Mad Unix wrote: > >> I was wandering if anyone know a good way to sync 2mysql databases >> _one_way >> The mysql is alocated on a web php application >> > Do they (DB) need to be identical ? Have you checked replication ? > > Regards, > Ranjeet Walunj > > > -- Madunix_at_Gmail Sysadmin "Computers are useless. They can only give you answers" - Pablo Picasso "Never trust a computer you can't throw out a window." - Steve Wozniak
RE: sync
can you provide a testcase would justify 2 different DB schemas?If you're willing to stay with identical configurations take a look at http://dev.mysql.com/doc/refman/5.0/en/replication.htmlHTHMartin __ Disclaimer and confidentiality note Everything in this e-mail and any attachments relates to the official business of Sender. This transmission is of a confidential nature and Sender does not endorse distribution to any party other than intended recipient. Sender does not necessarily endorse content contained within this transmission. > Date: Mon, 1 Sep 2008 17:58:10 +0530> From: [EMAIL PROTECTED]> To: [EMAIL PROTECTED]> CC: mysql@lists.mysql.com> Subject: Re: sync> > Mad Unix wrote:> > I was wandering if anyone know a good way to sync 2mysql databases _one_way> > The mysql is alocated on a web php application> Do they (DB) need to be identical ? Have you checked replication ?> > Regards,> Ranjeet Walunj> > > > -- > MySQL General Mailing List> For list archives: http://lists.mysql.com/mysql> To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]> _ Get thousands of games on your PC, your mobile phone, and the web with Windows®. http://clk.atdmt.com/MRT/go/108588800/direct/01/
Re: sync
Mad Unix wrote: I was wandering if anyone know a good way to sync 2mysql databases _one_way The mysql is alocated on a web php application Do they (DB) need to be identical ? Have you checked replication ? Regards, Ranjeet Walunj -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED]
Re: sync
Hi, Have you tried mk-table-sync from the Maatkit toolset http://www.maatkit.org/tools.html Ewen On Mon, Sep 1, 2008 at 2:12 PM, Mad Unix <[EMAIL PROTECTED]> wrote: > I was wandering if anyone know a good way to sync 2mysql databases _one_way > The mysql is alocated on a web php application. > > Thanks > > > -- > Madunix_at_Gmail > Sysadmin > > "Computers are useless. They can only give you answers" - Pablo Picasso > "Never trust a computer you can't throw out a window." - Steve Wozniak > -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED]
sync
I was wandering if anyone know a good way to sync 2mysql databases _one_way The mysql is alocated on a web php application. Thanks -- Madunix_at_Gmail Sysadmin "Computers are useless. They can only give you answers" - Pablo Picasso "Never trust a computer you can't throw out a window." - Steve Wozniak
