Re: Locking TABLES for myisamchk, please help!!
I understand all of the reasons given by Alexander. Yet I think that in 99% of cases, it would be best for myisamchk to do as Mark suggest, and not run when a MySQL server is active. Safety would be the default. There could be a special option (--no-safety) for myisamchk to override that check. - Original Message - From: "Alexander Keremidarski" <[EMAIL PROTECTED]> Newsgroups: mailing.database.mysql Sent: Thursday, May 23, 2002 1:54 AM Subject: Re: Locking TABLES for myisamchk, please help!! > Mark wrote: > > Wednesday, May 22, 2002, 9:23:02 AM, louie wrote: > > > > Personally, I find the behavior of myisasmchk to be a bit "beta" when it > > comes live tables. It would be real easy for myisasmchk to refuse to run > > when mysqld is running. That should be a built-in precaution. I can > > understand possible objections to myisasmchk globally locking tables > > out of the blue (it might disrupt what some clients are doing), but if > > myisamchk cannot run on a live table, it should not run on a live table. > > As simple as that. > > Hi, > It is not that simple. > > You can run several mysqld simultaneously. So checking if mysqld is > running is not enough. > > Or you might wish to use myisamchk knowing in advance that mysqld will > not write to table. > > Typical case is to check 'offline' database or table. Backup copy for > example. > > Another case: You want to check table which is read-only for all mysql > users and for some reason (different priority, buffers used etc.) you > don't want to do it with REPAIR TABLE. > > myisamchk uses tables as files so it is admin responcibility to avoid > problems. It is dangerous to use it but it is possible. > > You can compare it to filesystem checks. It is admin to decide if he can > handle it with live server or not. - Before posting, please check: http://www.mysql.com/manual.php (the manual) http://lists.mysql.com/ (the list archive) To request this thread, e-mail <[EMAIL PROTECTED]> To unsubscribe, e-mail <[EMAIL PROTECTED]> Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php
Re: Locking TABLES for myisamchk, please help!!
Mark wrote: > Wednesday, May 22, 2002, 9:23:02 AM, louie wrote: > Personally, I find the behavior of myisasmchk to be a bit "beta" when it > comes live tables. It would be real easy for myisasmchk to refuse to run > when mysqld is running. That should be a built-in precaution. I can > understand possible objections to myisasmchk globally locking tables out of > the blue (it might disrupt what some clients are doing), but if myisamchk > cannot run on a live table, it should not run on a live table. As simple as > that. Hi, It is not that simple. You can run several mysqld simultaneously. So checking if mysqld is running is not enough. Or you might wish to use myisamchk knowing in advance that mysqld will not write to table. Typical case is to check 'offline' database or table. Backup copy for example. Another case: You want to check table which is read-only for all mysql users and for some reason (different priority, buffers used etc.) you don't want to do it with REPAIR TABLE. myisamchk uses tables as files so it is admin responcibility to avoid problems. It is dangerous to use it but it is possible. You can compare it to filesystem checks. It is admin to decide if he can handle it with live server or not. -- Best regards -- For technical support contracts, visit https://order.mysql.com/ __ ___ ___ __ / |/ /_ __/ __/ __ \/ /Mr. Alexander Keremidarski <[EMAIL PROTECTED]> / /|_/ / // /\ \/ /_/ / /__ MySQL AB, Full-Time Developer /_/ /_/\_, /___/\___\_\___/ Sofia, Bulgaria <___/ www.mysql.com M: +359 88 231668 - Before posting, please check: http://www.mysql.com/manual.php (the manual) http://lists.mysql.com/ (the list archive) To request this thread, e-mail <[EMAIL PROTECTED]> To unsubscribe, e-mail <[EMAIL PROTECTED]> Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php
Re: Locking TABLES for myisamchk, please help!!
Wednesday, May 22, 2002, 9:23:02 AM, louie wrote: lm> Hi, i was thingking about locking the tables first so no connection lm> could write so i can do myisamchk. Is this process safe? lm> Procedures: lm> 1. lockdb lm> 2. run myisamchk -r or -o lm> 3. unlock db lm> Btw, mysqld is running. I want to off it but i can't its a production lm> server. lm> Hope anyone could give me more info. Personally, I find the behavior of myisasmchk to be a bit "beta" when it comes live tables. It would be real easy for myisasmchk to refuse to run when mysqld is running. That should be a built-in precaution. I can understand possible objections to myisasmchk globally locking tables out of the blue (it might disrupt what some clients are doing), but if myisamchk cannot run on a live table, it should not run on a live table. As simple as that. - Mark - Before posting, please check: http://www.mysql.com/manual.php (the manual) http://lists.mysql.com/ (the list archive) To request this thread, e-mail <[EMAIL PROTECTED]> To unsubscribe, e-mail <[EMAIL PROTECTED]> Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php
Re: Locking TABLES for myisamchk, please help!!
louie, Wednesday, May 22, 2002, 9:23:02 AM, you wrote: lm> Hi, i was thingking about locking the tables first so no connection lm> could write so i can do myisamchk. Is this process safe? lm> Procedures: lm> 1. lockdb lm> 2. run myisamchk -r or -o lm> 3. unlock db lm> Btw, mysqld is running. I want to off it but i can't its a production lm> server. lm> Hope anyone could give me more info. Don't run myisamchk when MySQL is running! Use REPAIR TABLE instead of myisamchk: http://www.mysql.com/doc/R/E/REPAIR_TABLE.html lm> ty, lm> louie... -- For technical support contracts, goto https://order.mysql.com/?ref=ensita This email is sponsored by Ensita.net http://www.ensita.net/ __ ___ ___ __ / |/ /_ __/ __/ __ \/ /Egor Egorov / /|_/ / // /\ \/ /_/ / /__ [EMAIL PROTECTED] /_/ /_/\_, /___/\___\_\___/ MySQL AB / Ensita.net <___/ www.mysql.com - Before posting, please check: http://www.mysql.com/manual.php (the manual) http://lists.mysql.com/ (the list archive) To request this thread, e-mail <[EMAIL PROTECTED]> To unsubscribe, e-mail <[EMAIL PROTECTED]> Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php
Locking TABLES for myisamchk, please help!!
Hi, i was thingking about locking the tables first so no connection could write so i can do myisamchk. Is this process safe? Procedures: 1. lockdb 2. run myisamchk -r or -o 3. unlock db Btw, mysqld is running. I want to off it but i can't its a production server. Hope anyone could give me more info. ty, louie... - Before posting, please check: http://www.mysql.com/manual.php (the manual) http://lists.mysql.com/ (the list archive) To request this thread, e-mail <[EMAIL PROTECTED]> To unsubscribe, e-mail <[EMAIL PROTECTED]> Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php
