1stly. Did the system originally use a file based DB like Paradox. If the answer
is yes, is the new app using TTables or TQueries. This is the first bottleneck
and relates to C/S developement in general.
There are several other things that can cause this, and they are not necessarily
related to MIDAS. (all off the top of my head)
Are they retrieving some records and then doing lookups for other information
on the records retrieved, ie have a db grid of all the records in one table
with a lookup field (excellent on file based DB's but on C/S not good)
Have they only got one BDE connection that all the RDM's share. Each RDM should
have it's own TDatabase and TSession (unless the programmer has implemented
some sort of connection pool).
Are the queries to retrieve the information in Interbase optimised? ie no Naturals
in the Plans for the queries.
Which MIDAS connection method are they using Sockets, DCOM, WebConnection?
Sockets is the fastest. If sockets then check that the SCKTSVR has the resolve
host names set off.
Are the Remote Data Modules (RDM) in the server all opened at the start or opened
as required. If opened as required are the RDM's broken into logical smaller
groups ie Order RDM containing the Order header and order details etc.
The BDE will suffer under MIDAS if there is a TDatabase and TSession per RDM
if there are likely to be more than 60 open at a time (we actually found that
this was lower like around 25) and will lock clients. I would strongly recommend
that IBX or IBO is used to avoid the BDE for MIDAS, unless they want to use
the SharedConnection methods in the RDMs.
I would suggest that you look at http://www.distribucon.com for other tips relating
to MIDAS. The Shared Connection information can be found there.
The borland newsgroups or www.deja.com is also a good place for information
relating to MIDAS etc.
IBX updates are available from
http://codecentral.borland.com/codecentral/ccweb.exe/author?authorid=102
IBO is at http://www.ibobjects.com/
HTH
Peter Speden
>Someone has just upgraded one of my old systems to three-tier.
>There seems to be a serious bottle-neck between the middle tier (Midas) and
>the back-end (Interbase).
>At the moment they are still using BDE components.
>
>Having never used Midas in anger, I am not much help.
>Does anyone know of any significant gotchas that need designing around?
>
>
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