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#21
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Opening Access db via DAO in vb.net
"Norman Yuan" schreef in bericht
... With all other replies being post, I am just wondering: why on the earth do you need to use DAO in .NET? "Michel Posseth [MCP]" wrote in message ... Well after thoroughly thinking about this question , the answer seems You don`t :-) Or maybe we are both missing something here What you're missing is that it's not .NET that is using DAO as much as the JET engine. And you can use ADO very successfully with the JET engine, but is will be slower. Typically, that speed in a well designed database with a well designed query is of little concern, becuase it is not likely that you will be searching through more than 100K rows in JET, so a 1/2 second doesn't mean much. But if you are looping through a recordset with 100K of rows, it can mean a significant difference. -- Arvin Meyer, MCP, MVP http://www.datastrat.com http://www.mvps.org/access http://www.accessmvp.com |
#22
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Opening Access db via DAO in vb.net
"Spam Catcher" wrote in message
. 1... Agreed - Acecss is the way of the Dodo in terms of application development. Microsoft has pretty much pigeon holed it into a pure personal desktop database now. My clients which include Fortune 500 companies, Federal and local government, and numerous others will be quite surprised. Departmental and low user count applications are Access's forte. I do suspect that there are far more single user Access applications, but the number multi-user apps runs in the millions. -- Arvin Meyer, MCP, MVP http://www.datastrat.com http://www.mvps.org/access http://www.accessmvp.com |
#23
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Opening Access db via DAO in vb.net
"Arvin Meyer [MVP]" wrote in
: My clients which include Fortune 500 companies, Federal and local government, and numerous others will be quite surprised. Departmental and low user count applications are Access's forte. I do suspect that there are far more single user Access applications, but the number multi-user apps runs in the millions. Yes, it "works", butmost developers are only using it because it is what they're comfortable with. But with all the limitations with Access such as the threat of DB corruption in a multi-user environment, why not use a real embedded DB like SQL Compact Edition? Even Microsoft acknowledges that Access isn't intended to be a general purposes database engine - rather a personal DB: http://www.microsoft.com/sql/edition...omparison.mspx I just don't see the point of using Access anymore when there are better alternatives out there. -- (Do not e-mail) |
#24
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Opening Access db via DAO in vb.net
"Arvin Meyer [MVP]" wrote in
: What you're missing is that it's not .NET that is using DAO as much as the JET engine. And you can use ADO very successfully with the JET engine, but is will be slower. Typically, that speed in a well designed database with a well designed query is of little concern, becuase it is not likely that you will be searching through more than 100K rows in JET, so a 1/2 second doesn't mean much. But if you are looping through a recordset with 100K of rows, it can mean a significant difference. If you're processing 100K rows, shouldn't that be a red flag that you're making access do something it's not designed to do? Access is a personal database - for that much data I'm sure you'll get better performance with SQL Server Express. Yes, it's more software to install, but it can always be installed on a central server and shared amongst multiple clients? -- (Do not e-mail) |
#25
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Opening Access db via DAO in vb.net
"Spam Catcher" wrote in message . 1... "Arvin Meyer [MVP]" wrote in : Yes, it "works", butmost developers are only using it because it is what they're comfortable with. But with all the limitations with Access such as the threat of DB corruption in a multi-user environment, why not use a real embedded DB like SQL Compact Edition? Since I'm a database developer, and I do use several different database engines, including SQL-Server, I might be able to shed some light on the reasons. First of all, we must separate Access from JET, which is one of the engines which is usable with Access. I am assuming that you mean the JETengine. JET, being a file-server based engine can corrupt if the data is used in bound forms, if there is a disconnect during a write. Server based engines are less likely to corrupt in that situation. Now practically speaking, that doesn't happen much with decent quality equipment. As a matter of fact, in my own experience, the last time I had any corruption was in the Spring of 2003 when the client had a faulty Dell WiFi card. Actually, I've only experience corruption there's a memo field in the table being written to during the write action. Multi-user has nothing at all to do with it, even a single user writing to a database located on a server can trigger corruption. So when is there a good reason to use JET? Usually when cost is involved because development is faster with JET and it's already on most user's machines. There are also a few other reasons, like being able to use VBA functions and even api's within queries, connecting multiple dissimilar engines, etc. When would I choose SQL-Server or another server based engine? A number of reasons: 1. Large number of users. 2. The data is already in SQL-Server. 3. Security needs to be enforced at a high level. 4. Database is in use 24/7 and must be maintained without interference. 5. Flaky hardware or network that can't be fixed 6. Large project with more than 500 MB of data 7. Most of the users are on a WAN Most databases do not fall into the above 7 reasons. The overwhelming number are small business or departmental databases, used by less than a dozen users and maintained by one of them. JET is an excellent engine for them. -- Arvin Meyer, MCP, MVP http://www.datastrat.com http://www.mvps.org/access http://www.accessmvp.com |
#26
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Opening Access db via DAO in vb.net
"Spam Catcher" wrote in message
. 1... If you're processing 100K rows, shouldn't that be a red flag that you're making access do something it's not designed to do? Access is a personal database - for that much data I'm sure you'll get better performance with SQL Server Express. Yes, it's more software to install, but it can always be installed on a central server and shared amongst multiple clients? 100K rows is a pittance for JET. I've searched through a half million rows of data in a few seconds with properly designed indexes. SQL-Server Express is about the same speed. Now if you have millions of rows of data, the full SQL-Server product is definitely the one to choose. I'm really sorry that you think that Access/JET is a single-user database. You're obviously missing giving some of your users a fast, easily maintainable solution. -- Arvin Meyer, MCP, MVP http://www.datastrat.com http://www.mvps.org/access http://www.accessmvp.com |
#27
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Opening Access db via DAO in vb.net
"Spam Catcher" wrote in message . 1... If you're processing 100K rows, shouldn't that be a red flag that you're making access do something it's not designed to do? No! I have developed, and continue to support, three systems in which there is a table of nearly three million records. To date I have had no corruption issues and no performance issues. Ed Metcalfe. |
#28
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Opening Access db via DAO in vb.net
"Michel Posseth [MCP]" wrote in message ... You talk as a ACCESS developer , a person who writes solutions completely in ACCESS , throws in some Access forms and or VBA No, I talk as a developer who uses Access for certain situations. When it is not appropriate and a better alternative is available then I will pick an alternative. Ed Metcalfe. |
#29
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Opening Access db via DAO in vb.net
"Ed Metcalfe" wrote in message ... "Spam Catcher" wrote in message . 1... If you're processing 100K rows, shouldn't that be a red flag that you're making access do something it's not designed to do? No! I have developed, and continue to support, three systems in which there is a table of nearly three million records. To date I have had no corruption issues and no performance issues. Ed Metcalfe. And just to clarify, these are multi-user systems not single-user systems. Ed Metcalfe. |
#30
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Opening Access db via DAO in vb.net
"Arvin Meyer [MVP]" wrote in message ... As you can see, that article hasn't been updated in over 4 years. There may be some info on the Access Team blog: http://blogs.msdn.com/access/ I did a cursory search using DAO vs ADO and found: http://blogs.msdn.com/access/search....DAO+vs+ADO&p=1 which seems to mention several postings by the MS-Access PMs on using DAO in Access 2007. Sorry I did not do further research, but you're welcome to. -- Arvin Meyer, MCP, MVP http://www.datastrat.com http://www.mvps.org/access http://www.accessmvp.com Thank you. I'll do some further reading tomorrow. Ed Metcalfe. |
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