Re: removing ibdata1 if some/all tables are not InnoDB?
Carl, InnoDB does purge deleted rows from the ibdata files. Certain PostgreSQL advocates have been spreading a claim that InnoDB would not do that, but the claim is false. If your ibdata file keeps growing indefinitely, please check with SHOW INNODB STATUS that you do commit all your transactions. If a transaction stays open for months, then the purge cannot remove deleted rows. If you convert ALL your tables from InnoDB to MyISAM, then you can remove the ibdata files and ib_logfiles. If you put skip-innodb to my.cnf, then those files will not be created again. Best regards, Heikki Oracle Corp./Innobase Oy InnoDB - transactions, row level locking, and foreign keys for MySQL InnoDB Hot Backup - a hot backup tool for InnoDB which also backs up MyISAM tables http://www.innodb.com/order.php - Original Message - From: Alex [EMAIL PROTECTED] Newsgroups: mailing.database.myodbc Sent: Tuesday, January 03, 2006 6:55 AM Subject: Re: removing ibdata1 if some/all tables are not InnoDB? HI Carl, The ibdata file growth can be stopped by removing the autoextend keyword in the my.cnf file. In your my.cnf file the entry might be innodb_data_file_path = ibdata1:256M:autoextend If you want to stop the growth of that file and add another file then this is what you want to do. 1. Stop the mysql server 2. Get the size of the ibdata1 file in MB (Lets say its 5600MB in size) 3. edit the my.cnf file and replace innodb_data_file_path = ibdata1:256M:autoextend with innodb_data_file_path = ibdata1:5600M;ibdata2:256M:autoextend 4. Start the server. This will stop that file from growing and a new file will be added that can pushed on to a different disk and symlinked into the ibdata directory. Data growth is a problem in all table types. Even if you migrate to MyISAM you need space. See whether there is log_bin turned on the server. If so there might be lots of bin log files that you can do a cleanup on. Bin logs occupy a great deal of space. Thanx Alex, MySQL DBA Yahoo! On Tue, 03 Jan 2006 08:28:24 +0530, Carl Brewer [EMAIL PROTECTED] wrote: Hello, I'm stuck with a rapidly decreasing amount of available disk space and a requirement to keep a lid on the size of our databases. We're using MySQL 4.1.12 as bundled with RHEL ES 4. We do a lot of transactions keeping short term track of webserver sessions, which we don't need to keep logs of for very long. I have a number of databases, almost all of which are using MyISAM or HEAP, and one database using InnoDB. As such (or at least, as I understand it) we have a ibdata1 file that will grow forever and AFAIK there's no way to stop it growing forever for as long as we have that InnoDB database. Am I correct? I'm no MySQL guru, my parsing of TFM and googling around and finding bug and feature requests for ibdata1 purging suggests that this is the case. If so, if I drop the InnoDB database, stop mysqld, delete (UNIX filesystem) the imdata1 file, restart mysqld and import a (modified to be MyISAM) dumped copy of the InnoDB database, will that work without damaging anything and then not leave me with another infinatly growing imdata1 file? Am I correct in assuming that InnoDB databases are meant for sites where disk space is not ever likely to be an issue, and MyISAM is a more suitable database engine for our much tighter disk space situation? I may have missed a section of the doco that discusses why one would choose an engine over another? Thanks for any advice, Carl -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED] -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED]
Re: removing ibdata1 if some/all tables are not InnoDB?
Heikki Tuuri wrote: Carl, InnoDB does purge deleted rows from the ibdata files. Certain PostgreSQL advocates have been spreading a claim that InnoDB would not do that, but the claim is false. Could You explain more about reusing space previously taken by deleted rows? Is this concept similar to Oracle's concepts in this regard ? Regards Remigusz -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED]
Re: removing ibdata1 if some/all tables are not InnoDB?
InnoDB does purge deleted rows from the ibdata files. Certain PostgreSQL advocates have been spreading a claim that InnoDB would not do that, but the claim is false. If your ibdata file keeps growing indefinitely, please check with SHOW INNODB STATUS that you do commit all your transactions. If a transaction stays open for months, then the purge cannot remove deleted rows. If you convert ALL your tables from InnoDB to MyISAM, then you can remove the ibdata files and ib_logfiles. If you put skip-innodb to my.cnf, then those files will not be created again. I don't think there is a question as to whether or not InnoDB will purge data and re-use space, the question is whether or not the ibdata files will be shrunk when that space is purged. My understanding (and experience) has always shown that ibdata files - while they may purge and re-use unused space, will not shrink themselves based on the actual space usage. Is that not correct? I.e., if I have 100 MB of table data, and say - delete 6 tables (which would result in InnoDB recovering all that space), that results in only 10MB of space being used, the file will be re-sized to 10MB - or something smaller than 100 MB. The practical example would be if I were to accidentally add 1GB of data to my InnoDB tablespace, and then remove it. Would my total ibdata file sizes total less than 1GB of space (now I'm just using 100MB)? If that were the case it would be a simple matter of switching to 'tablespace per table', migrating the data to the individual tables (which would shrink the ibdata files), re-structuring the ibdata files (to use other partitions, etc.) an the moving the data back into the tablespace. Thanks -- Chander Ganesan Open Technology Group, Inc. One Copley Parkway, Suite 210 Morrisville, NC 27560 Phone: 877-258-8987/919-463-0999 http://www.otg-nc.com Best regards, Heikki Oracle Corp./Innobase Oy InnoDB - transactions, row level locking, and foreign keys for MySQL InnoDB Hot Backup - a hot backup tool for InnoDB which also backs up MyISAM tables http://www.innodb.com/order.php - Original Message - From: Alex [EMAIL PROTECTED] Newsgroups: mailing.database.myodbc Sent: Tuesday, January 03, 2006 6:55 AM Subject: Re: removing ibdata1 if some/all tables are not InnoDB? HI Carl, The ibdata file growth can be stopped by removing the autoextend keyword in the my.cnf file. In your my.cnf file the entry might be innodb_data_file_path = ibdata1:256M:autoextend If you want to stop the growth of that file and add another file then this is what you want to do. 1. Stop the mysql server 2. Get the size of the ibdata1 file in MB (Lets say its 5600MB in size) 3. edit the my.cnf file and replace innodb_data_file_path = ibdata1:256M:autoextend with innodb_data_file_path = ibdata1:5600M;ibdata2:256M:autoextend 4. Start the server. This will stop that file from growing and a new file will be added that can pushed on to a different disk and symlinked into the ibdata directory. Data growth is a problem in all table types. Even if you migrate to MyISAM you need space. See whether there is log_bin turned on the server. If so there might be lots of bin log files that you can do a cleanup on. Bin logs occupy a great deal of space. Thanx Alex, MySQL DBA Yahoo! On Tue, 03 Jan 2006 08:28:24 +0530, Carl Brewer [EMAIL PROTECTED] wrote: Hello, I'm stuck with a rapidly decreasing amount of available disk space and a requirement to keep a lid on the size of our databases. We're using MySQL 4.1.12 as bundled with RHEL ES 4. We do a lot of transactions keeping short term track of webserver sessions, which we don't need to keep logs of for very long. I have a number of databases, almost all of which are using MyISAM or HEAP, and one database using InnoDB. As such (or at least, as I understand it) we have a ibdata1 file that will grow forever and AFAIK there's no way to stop it growing forever for as long as we have that InnoDB database. Am I correct? I'm no MySQL guru, my parsing of TFM and googling around and finding bug and feature requests for ibdata1 purging suggests that this is the case. If so, if I drop the InnoDB database, stop mysqld, delete (UNIX filesystem) the imdata1 file, restart mysqld and import a (modified to be MyISAM) dumped copy of the InnoDB database, will that work without damaging anything and then not leave me with another infinatly growing imdata1 file? Am I correct in assuming that InnoDB databases are meant for sites where disk space is not ever likely to be an issue, and MyISAM is a more suitable database engine for our much tighter disk space situation? I may have missed a section of the doco that discusses why one would choose an engine over another? Thanks for any advice, Carl -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED] -- MySQL General
Re: removing ibdata1 if some/all tables are not InnoDB?
You can stop the auto-growth of your ibdata1 file, and add additional ibdata files (as needed) on different disks/partitions. However, you cannot currently shrink the file without some work.. Check out the MySQL documentation for innodb_data_file_path (that is the config setting that you would use in the my.cnf file to set things up). You'll have to find out the size in MB of your current file (ls -lh) when you do this (if you want to start a new innodb data file on a separate disk, etc.), since in my experience MySQL will complain if you specify the size of the file incorrectly. InnoDB is great when you have a lot of transactions going on, need rollback capability (batch operations that should either succeed as a whole or fail as a whole) - or you need ACID compliance. MyISAM is fast for lookups, but requires a table lock to be acquired for updates, and most inserts (except in certain cases) - so its fast for lookups, but not as good for updates. Each have their own distinct advantages... HEAP is good when you don't care if your data sticks around, and you need fast access to it (such as web cookies...) As far as purging - you'd be best off doing an export, trash your InnoDB tables, and then import . -- Chander Ganesan Open Technology Group, Inc. One Copley Parkway, Suite 210 Morrisville, NC 27560 http://www.otg-nc.com Phone: 877-258-8987/919-463-0999 Fax: 919-386-0158 Expert MySQL Training Carl Brewer wrote: Hello, I'm stuck with a rapidly decreasing amount of available disk space and a requirement to keep a lid on the size of our databases. We're using MySQL 4.1.12 as bundled with RHEL ES 4. We do a lot of transactions keeping short term track of webserver sessions, which we don't need to keep logs of for very long. I have a number of databases, almost all of which are using MyISAM or HEAP, and one database using InnoDB. As such (or at least, as I understand it) we have a ibdata1 file that will grow forever and AFAIK there's no way to stop it growing forever for as long as we have that InnoDB database. Am I correct? I'm no MySQL guru, my parsing of TFM and googling around and finding bug and feature requests for ibdata1 purging suggests that this is the case. If so, if I drop the InnoDB database, stop mysqld, delete (UNIX filesystem) the imdata1 file, restart mysqld and import a (modified to be MyISAM) dumped copy of the InnoDB database, will that work without damaging anything and then not leave me with another infinatly growing imdata1 file? Am I correct in assuming that InnoDB databases are meant for sites where disk space is not ever likely to be an issue, and MyISAM is a more suitable database engine for our much tighter disk space situation? I may have missed a section of the doco that discusses why one would choose an engine over another? Thanks for any advice, Carl -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED]
Re: removing ibdata1 if some/all tables are not InnoDB?
HI Carl, The ibdata file growth can be stopped by removing the autoextend keyword in the my.cnf file. In your my.cnf file the entry might be innodb_data_file_path = ibdata1:256M:autoextend If you want to stop the growth of that file and add another file then this is what you want to do. 1. Stop the mysql server 2. Get the size of the ibdata1 file in MB (Lets say its 5600MB in size) 3. edit the my.cnf file and replace innodb_data_file_path = ibdata1:256M:autoextend with innodb_data_file_path = ibdata1:5600M;ibdata2:256M:autoextend 4. Start the server. This will stop that file from growing and a new file will be added that can pushed on to a different disk and symlinked into the ibdata directory. Data growth is a problem in all table types. Even if you migrate to MyISAM you need space. See whether there is log_bin turned on the server. If so there might be lots of bin log files that you can do a cleanup on. Bin logs occupy a great deal of space. Thanx Alex, MySQL DBA Yahoo! On Tue, 03 Jan 2006 08:28:24 +0530, Carl Brewer [EMAIL PROTECTED] wrote: Hello, I'm stuck with a rapidly decreasing amount of available disk space and a requirement to keep a lid on the size of our databases. We're using MySQL 4.1.12 as bundled with RHEL ES 4. We do a lot of transactions keeping short term track of webserver sessions, which we don't need to keep logs of for very long. I have a number of databases, almost all of which are using MyISAM or HEAP, and one database using InnoDB. As such (or at least, as I understand it) we have a ibdata1 file that will grow forever and AFAIK there's no way to stop it growing forever for as long as we have that InnoDB database. Am I correct? I'm no MySQL guru, my parsing of TFM and googling around and finding bug and feature requests for ibdata1 purging suggests that this is the case. If so, if I drop the InnoDB database, stop mysqld, delete (UNIX filesystem) the imdata1 file, restart mysqld and import a (modified to be MyISAM) dumped copy of the InnoDB database, will that work without damaging anything and then not leave me with another infinatly growing imdata1 file? Am I correct in assuming that InnoDB databases are meant for sites where disk space is not ever likely to be an issue, and MyISAM is a more suitable database engine for our much tighter disk space situation? I may have missed a section of the doco that discusses why one would choose an engine over another? Thanks for any advice, Carl -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED]
