Here is another question. Can you achieve the same performance having to different kinds of databases as though you were only using one? I am assuming that you are going to run into problems because you cannot set both types of databases to have a lot of memory allocated to them. Right?
On Mon, 11 Oct 2004 09:23:18 -0700, John McCaskey <[EMAIL PROTECTED]> wrote: > As far as I know memory usage between the two table types is roughly the > same. The way memory is setup/used is somewhat different however. For > myisam the primary memoy buffer to accelerate queries is the key_buffer > which caches data for keys. In innodb you have more options to set with > the main one being the innodb_buffer_pool_size which is used for caching > keys and data, you want to set this as large as possible. You also have > several other adjustable buffers inlcuing an 'additonal_mem_pool' which > I'm not quite sure what it is used for, and the log_buffer which is used > for transaction related memory I believe. > > So, if you are going to be using both MyISAM and InnoDB you will need > seperate buffers, which will of course increase total memory usage, or > leave a smaller size for both. But if you switch completely to InnoDB > you can drop the MyISAM buffers down to almost nothing (still need them > as the mysql table with user data etc uses them, but say 8megs would be > plenty). > > John > > On Sun, 2004-10-10 at 10:51 +0200, Jacques Jocelyn wrote: > > > > > > Hello John, > > > > Interesting post, quite useful, > > Question about performance with InnoDB ? > > say you have a hosting server with 256 Mb of ram, would you know if > > that will make a difference if the major database is converted from > > MyIsam to InnoDb ? > > > > Although, InnoDB is not a requirement, just luxury, but I would love > > to enjoy foreign keys and transactions > > > > Please advise, > > Thanks > > > > > > Sunday, October 10, 2004, 8:39:15 AM, you wrote: > > > > JM> I meant 'No transaction support', which is you can't use > > JM> begin work; ... ; commit; etc to perform transactions, each query > > JM> takes effect immeiately and is visible to all other > > JM> threads/clients immediately. > > ... > > > > JM> Concurrency refers to multiple seperate connections (threads) > > JM> trying to read/write to/from the same table at the same time. > > JM> Imagine you have 100 different connections to the database all > > JM> trying to write to the same table. With MyISAM each one will lock > > JM> the entire table, and only one will execute at a time, making it > > JM> very slow. In InnoDB each one will only lock the rows it is > > JM> modifying and they can all execute at once (if they are not > > JM> modifying the same rows), and it will be very fast. > > > > > > > > > > Best regards, > > Jacques Jocelyn > > > > -- > MySQL General Mailing List > For list archives: http://lists.mysql.com/mysql > To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED] > > -- Benjamin Arai http://www.cs.ucr.edu/~barai [EMAIL PROTECTED] -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
