|
| Clark F Morris wrote:
> On Wed, 10 Oct 2007 16:35:49 -0600, "Frank Swarbrick"
> <Frank.Swarbrick@efirstbank.com> wrote:
>
>
[snip]
> Switching to
> static SQL apparently got rid of much of the performance problem.
> Since this is second hand from one of those involved, I am sketchy on
> the detail but I suspect it may in part have to do with bind and
> parsing overhead. Those who are really into data base probably can
> explain the trade-offs and technical issues far better than I can.
On the Unisys mainframe, these were the metrics they gave us. Assuming
a dynamic statement created at run time takes "1", the same query as
static SQL takes ".6". When a program is compiled, it stores a checksum
of each table that it accesses. If the program finds that the table has
changed, it does an on-the-fly recompilation of the statement - this
takes ".65".
These are all for the first execution. Subsequent executions of
prepared statements or recompiled queries is ".6". And, of course,
these numbers are only valid on a Unisys 2200-series mainframe, using
COBOL 85 and Unisys' RDMS relational database server. :)
--
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
~~~~~~~~~~~~~~~~~~~~~~~~~~~
~ / \/ _ o ~ Live from Albuquerque, NM! ~
~ _ /\ | ~ ~
~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
~ Business E-mail ~ daniel @ "Business Website" below ~
~ Business Website ~ http://www.djs-consulting.com ~
~ Tech Blog ~ http://www.djs-consulting.com/linux/blog ~
~ Personal E-mail ~ "Personal Blog" as e-mail address ~
~ Personal Blog ~ http://daniel.summershome.org ~
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
~~~~~~~~~~~~~~~~~~~~~~~~~~~
GEEKCODE 3.12 GCS/IT d s-:+ a C++ L++ E--- W++ N++ o? K- w$ !O M--
V PS+ PE++ Y? !PGP t+ 5? X+ R* tv b+ DI++ D+ G- e h---- r+++ z++++
"Who is more irrational? A man who believes in a God he doesn't see,
or a man who's offended by a God he doesn't believe in?" - Brad Stine
|
|