Microsoft Access is a slick way to access data in a MS SQL Server backend database, but I've always had problems accessing (so to speak) large tables of data, especially when trying to toggle between results and design mode in Access.
Access gives me a number of nifty things, not the least of which is Crosstabs, but this hung connection to the server drives me a little crazy!
Does any MS Access gurus know how to optimize the ODBC connection so it isn't doing what appears to be full table scans when I just want to tweak and build my queries?
The ODBC driver will pass as much work as possible to SQL Server but as soon as you use a vba function like Nz or non-SQL Server syntax like PIVOT then the ODBC driver must pull back more data and indexes to get the work done on the client side.
As per other answer either build your views in SQL Server and link to the views or else use an Access Data Project.
NB: PIVOT queries with unknown number of columns cannot be handled in SQL Server in the same way that Access will do this natively - so if you run a pivot in Access against SQL Server data you will likely pull the whole table back. Pivot queries must be built in SQL Server using dynamic SQL techniques or else pre-saved views that have all the columns hard coded. Check out this link for one way to do this:
http://www.sqlservercentral.com/articles/Advanced+Querying/pivottableformicrosoftsqlserver/2434/
As others have said, the only way to improve performance on large tables is to have the SQL Server database engine do the work for you. A method of doing this which hasn't been mentioned is to use a pass-through query, which will enable you to keep all your code in MS Access, without having to create objects on the SQL Server:
http://support.microsoft.com/kb/303968
You will have to write SQL Server T-SQL rather than the Access dialect; however, SQL 2005 (when running in compatibility mode 90) does support a PIVOT command.
My similar problem was that the ORACLE ODBC connection hung after selecting the Link table/ODBC connection. Task manager said not responding after 10's of minutes. The connection then pings ORACLE for all available tables. I had turned on logging on the ORACLE ODBC Administrator, so it had to write all these things to the log, slowing any results by perhaps hours. The log was 60 MB one hour later, when I turned it off, then everything was fine!
To turn it off go to the Oracle installation/Network Administration/MS ODBC Adminstrator/Tracing tab and turn it OFF!
A good resource on ODBC is here: http://eis.bris.ac.uk/~ccmjs/odbc_section.html
Unfortunately Access is not able to push a lot of that work to the server, and yes, it will do huge table scans when designing queries against multiple tables or views in SQL Server.
You can build and tweak queries (views) in SQL Server using SSMS and store the views in SQL Server for a massive performance boost and still use Access for your front end.
Related
I have an access database that is stored on a network drive where all users access the one file. The database is linked to Sql server tables located in a local on site server. In my vba code my connection is to the access database. My question is I know it's possible to just connect to sql server from vba but all my queries are stored in Access, so will my code be able to run the queries from access if it's connected to Sql server or would I need to re-write all the queries? The problem we are having is that more than one user may be on the same record pulled up and they are overwriting each other's changes. Also a user may need to take the program on their laptop instead of having to remote in to their desktop at office. I was thinking I could just give them a copy each and that would solve the problem. Does anyone have any answers?
Just re-write the queries in SQL Server. It may be painful now, but it shouldn't be too bad, and down the road a bit, you'll be glad you moved everything to SQL Server (much faster, more stable, you're using a real DB, etc.)
You will want to pull all the queries into VBA and rewrite them with the appropriate parameters.
We have several MS projects being used and a system written in SQL Server by us. Would MS Project Server allow us to set up something like SSIS procs to continuously get data from the MS Project databases and insert them into our SQL Server database?
Is there a way to link all systems or a better way to do this where we're not paying a monthly fee for MS Project Server? Would actually like to bypass MS Project Server if possible.
Thanks
Yes it is possible. You can write a vba routine which sends the schedule data up to a database. I've done this previously sending schedule data up to SQL server using ODBC.
You'd need to decide what data you want to see - getting task, resource and assignment data is quite straightforward, but if you need to look at time phased data that can slow things down. Then it's just a case of looping through the collections and using a SQL INSERT statement to squirt each task, assignment or resource up into the tables.
If that's all project server was being used for, then you can retire it and its supporting infrastructure. Additionally, you would then only need Project Standard client, which is about half the price of the Project Professional client.
We ported a database server from SQLServer 2005 to SQLServer 2008 (SP1). The new server has more Processors (4 Quadcore versus 1 Quadcore ) and more memory (4GB versus 64GB).
Processors are 2.1Ghz(new) versus 2.0Ghz(old).
The new OS is Windows Server 2008 and the old is Windows Server 2003.
The databases were transfered via backup/restore and run in native SQL Server 2008 mode (not in SQLServer 2005 compatability mode ).
Some queries on the new server run slower than before. These queries use indexed views. The queryplan looks the same on both systems.
Most of the queries perform equal.
My task is now to decide if we have a problem with our SQLServer installation, if the we have a problem with the database or if this is an expexted result.
I first want to compare performance of both
Sytems
SQLServer installations.
Is there an easy way to do this?
Has anybody had comparabele results on new SQLServer installations?
Before you check your hardware/OS, make sure you:
update statistics
rebuild all indexes
and then run your tests again. Also, are the editions of SQL Server identical? There are differences in how you have to write queries against indexed views based on the edition (Standard vs. Enterprise) of SQL Server.
Also, confirm that your indexed views are still indexed properly by selecting 1 row from them and observing the query plan. You should see only one table in the resulting plan.
The easiest way to collect performance of both systems is to run a PAL, and collect the approriate data.
PAL has extra counter sets for SQL Server. It will collect and analyse the data, and let you know where you have an issue.
PAL can be found here
http://www.codeplex.com/PAL
Also an important issu is to location of the filegroups. How is the underlying storrage system defined? It usually has a huge impact on the SQL Server. (You should talk about spindels here, and not raw size...) Make sure your database files are not sharing the resources with anyone else
I have a SQL Server 2005 machine with a JDE DB2 set up as a linked server.
For some reason the performance of any queries from this box to the db2 box are horrible.
For example. The following takes 7 mins to run from Management Studio
SELECT *
FROM F42119
WHERE SDUPMJ >= 107256
Whereas it takes seconds to run in iSeries Navigator
Any thoughts? I'm assuming some config issue.
In certain searches SQL Server will decide to pull the entire table down to itself and sort and search the data within SQL Server instead of sending the query to the remote server. This is usually a problem with collation settings.
Make sure the provider has the following options set:
Data Access,
Collation Compatible,
Use Remote Collation
Then create a new Linked Server using the provider and select the following provider options
Dynamic Parameters,
Nested Queries,
Allow In Process
After setting the options change the query slightly to get a new query plan.
It might be a memory issue on your SQL Server machine. I recently learned that linked server queries use memory allocation by the OS. Whereas native SQL Server queries use memory pre-allocated by SQL Server. If your SQL Server machine is configured to use 90% or more of the server's memory, I would scale that back a bit. Maybe 60% is the right place to be.
Another thing to check is the SQL Server processor priority. Make sure "Boost SQL Server priority" is not enabled.
I assume you are going through ODBC for access. Remember that you are not writing native db2 queries here, but instead ODBC sql queries. If you only need read-only data, you may want to try configuring your ODBC datasource to read-only mode (if that is an option).
In a project with DB2 integration, I replaced every query via direct select or view by stored procedures calling the OPENQUERY function.
My interpretation is that SqlServer fetches the whole table before applying the WHERE conditions, whereas OPENQUERY passes the SQL statement directly to the db driver.
Anyway, performance was acceptable after the modifications.
My first thought would go to the drivers. Years ago I had to link DB2 to SQL Server 2000 and it was extremely difficult to find the correct combination of drivers and setup parameters that would work...
So maybe I'm biased because of that, but I would try upgrading or downgrading the driver or changing the setup so that the DB2 driver can run INPROC (if it's not already doing so).
I've had several issues with DB2 as a linked a server. I do not know if it will address your problems, but here is what fixed mine:
1) Enabled lazy close support and pre-fetch during EXECUTE in the ODBC settings
2) Add "FOR FETCH ONLY" on all selects
3) Query using the SELECT * FROM OPENROWSET(LinkedServerName, 'SQL Command') method
This should be simple. I'm trying to import data from Access into SQL Server. I don't have direct access to the SQL Server database - it's on GoDaddy and they only allow web access. So I can't use the Management Studio tools, or other third-party Access upsizing programs that require remote access to the database.
I wrote a query on the Access database and I'm trying to loop through and insert each record into the corresponding SQL Server table. But it keeps erroring out. I'm fairly certain it's because of the HTML and God knows what other weird characters are in one of the Access text fields. I tried using CFQUERYPARAM but that doesn't seem to help either.
Any ideas would be helpful. Thanks.
Try using the GoDaddy SQL backup/restore tool to get a local copy of the database. At that point, use the SQL Server DTS tool to import the data. It's an easy to use, drag-and-drop graphical interface.
What error(s) get(s) thrown? What odd characters are you using? Are you referring to HTML markup, or extended (eg UTF-8) characters?
If possible, turn on Robust Error Reporting.
If the problem is the page timing out, you can either increase the timeout using the Admin, using the cfsetting tag, or rewrite your script to run a certain number of lines, and then forward to itself at the next start point.
You should be able to execute saved DTS packages in MS SQL Server from the application server's command line. Since this is the case, you can use <cfexecute> to issue a request to DTSRUNNUI.EXE. (See example) This is of course assuming you are on a server where the command is available.
It's never advisable to loop through records when a SQL Update can be used.
It's not clear from your question what database interface layer you are using, but it is possible with the right interfaces to insert data from a source outside a database if the interface being used supports both types of databases. This can be done in the FROM clause of your SQL statement by specifying not just the table name, but the connect string for the database. Assuming that your web host has ODBC drivers for Jet data (you're not actually using Access, which is the app development part -- you're only using the Jet database engine), the connect string should be sufficient.
EDIT: If you use the Jet database engine to do this, you should be able to specify the source table something like this (where tblSQLServer is a table in your Jet MDB that is linked via ODBC to your SQL Server):
INSERT INTO tblSQLServer (ID, OtherField )
SELECT ID, OtherField
FROM [c:\MyDBs\Access.mdb].tblSQLServer
The key point is that you are leveraging the Jet db engine here to do all the heavy lifting for you.