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Difference Between .ADP and .mdb 1

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JVZ

Programmer
Sep 3, 2002
205
CA
Could someone please explain what the differences between these two files are? I know the general difference, what I can not find the answer to is, why use Access Project instead a normal access database and just link the SQL Server tables to the .mdb file ? (performance reason?).
 
Generally it is performance, but it is also ease of maintenance. A project uses an OLE-DB connection and the MDAC libraries are included in the Windows 2000 operating system. So there is no messing around with ODBC setup and connections that are necessary with linking sql server tables. Access Project Forms will start displaying the data potentially as the data is being retrieved from sql server, whereas, in an MDB all the data is brought over to the client before any data is displayed. Stored Procedures can be used directly as the record source for Forms and Reports instead of going through pass-through queries as is necessary in an MDB with linked tables. The recordset objects in an ADP are ADO and can be manipulated through ADO methods and/or replaced with another ADO recordset that was manipulated. This is a start and maybe others can contribute additional benefits.
 
JVZ,

I'm making the leap from plain Access and Access using linked tables to Access Projects now. (I'm hoping to complete the leap, but sometimes I feel like I'm trying to jump the Grand Canyon, a'la Evil Knievel.)

There are MANY syntactical and operational differences. Part of your choice, if you have a choice, should be to consider your resources. Do you have an experienced person available or will you be searching help files and posting here? If you're on your own, I'd really consider before leaving plain Access. Plain IS more error prone and can have corrupt databases - you need to have a more effective backup strategy than you have to with the data on an SQL server.

But, IMHO, the overriding consideration is scale. If you're going to have more than 10 concurrent users, you need to use Project so that you can use pass-through queries to limit the amount of data going over the network. With linked tables, ALL of it comes to your PC for examination by queries. And, if you're going to have megabytes of data, even with fewer users there will be a performance difference.

HOWEVER, I'm converting some linked tables to pass-through queries right now and have reported that more work will be required to maintain the flexibility of rerunning with my PC backdated - because I can't backdate the SQL server. If that flexibility is deemed a requirement, I'm going to lose some of the performance advantage because I'll have to pass more data. Or, I'll have to reinvent by writing Stored Procedures to allow passing dates as parameters.

Gee, I'm becoming as long-winded as my sister. The preceding paragraph was intended to illustrate some nuances that can crop up.

HTH,
Bob
 
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