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13/04/2006, 17h48

tarscher@gmail.com wrote:
> Will my performance increase by making 2 tables; one
> with pressure and one with temperature?

I doubt it. Besides, I assume it would often be the case that you'd
want both figures, so you'd eliminate any potential gains anyway when
you join the two tables.

It sounds like you're going to be producing 2 records per second. Even
after a year of continuous measurement 24 hours per day, you'll have 63
million records. This may be reaching the upper bounds of what MySQL is
best suited for, but it can handle it. If you use indexes properly,
queries won't be too slow (certainly slower than after 1 day of
measurements, but that's to be expected).

There is a chapter in the MySQL docs about improving performance.
http://dev.mysql.com/doc/refman/5.0/...imization.html

There are also several articles on the MySQL web site in the "white
papers" section on achieving even greater scalability (larger databases,
faster performance) with other features of the product, like clustering
and partitioning. http://www.mysql.com/why-mysql/white-papers/

There are many companies using MySQL for high volume applications. See
http://www.mysql.com/why-mysql/case-studies/.

> 2) I have read that when querying the server in read mode opposed to
> read/write mode you can get a performance increase. Can this be done
> with php?

I have not heard of a feature called "read mode". Can you cite a reference?

You may be thinking of the REPEATABLE READ transaction isolation mode.
This doesn't increase performance, but reduces the likelihood that two
concurrent queries will block one another.

Regards,
Bill K.

13/04/2006, 17h48	#2
Bill Karwin Messages: n/a Hébergeur:	Re: performance question tarscher@gmail.com wrote: > Will my performance increase by making 2 tables; one > with pressure and one with temperature? I doubt it. Besides, I assume it would often be the case that you'd want both figures, so you'd eliminate any potential gains anyway when you join the two tables. It sounds like you're going to be producing 2 records per second. Even after a year of continuous measurement 24 hours per day, you'll have 63 million records. This may be reaching the upper bounds of what MySQL is best suited for, but it can handle it. If you use indexes properly, queries won't be too slow (certainly slower than after 1 day of measurements, but that's to be expected). There is a chapter in the MySQL docs about improving performance. http://dev.mysql.com/doc/refman/5.0/...imization.html There are also several articles on the MySQL web site in the "white papers" section on achieving even greater scalability (larger databases, faster performance) with other features of the product, like clustering and partitioning. http://www.mysql.com/why-mysql/white-papers/ There are many companies using MySQL for high volume applications. See http://www.mysql.com/why-mysql/case-studies/. > 2) I have read that when querying the server in read mode opposed to > read/write mode you can get a performance increase. Can this be done > with php? I have not heard of a feature called "read mode". Can you cite a reference? You may be thinking of the REPEATABLE READ transaction isolation mode. This doesn't increase performance, but reduces the likelihood that two concurrent queries will block one another. Regards, Bill K.