I'm trying to compare MS Access SQL queries for local table vs linked table
(it is linked to an Oracle and to a SQL Server database).
I can get query duration when running the SQL command directly on Oracle or SQL Server, but when running the SQL in MS Access, I don't know how to capture the query duration.
Is there a way to get the query duration when running a SQL command inside MS Access?
Thanks. :-)
Yes, it is.
Record in a variable the actual time.
Create a recordset with data source pointing to your query/view/table
Open the recordset (eventually you may check the recordcount)
Record in another variable the actual time
DateDiff between 1. amd 4.
Access does not provide that sort of information, unlike server databases.
You could use a Form Timer and get an idea of the duration, but with linked tables a lot of that depends on the network, server overhead, etc.
Related
We have a linked server (OraOLEDB.Oracle) defined in the SQL Server environment. Oracle 12c, SQL Server 2016. There is also an Oracle client (64 bit) installed on SQL Server.
When retrieving data from Oracle (a simple query, getting all columns from a 3M row, fairly narrow table, with varchars, dates and integers), we are seeing the following performance numbers:
sqlplus: select from Oracle > OS File on the SQL Server itself
less than 2k rows/sec
SSMS: insert into a SQL Server table select from Oracle using OpenQuery (passthrough to Oracle, so remote execution)
less than 2k rows/sec
SQL Export/Import tool (in essence, SSIS): insert into a SQL Server table, using the OLEDB Oracle for source and OLEDB SQL Server for target
over 30k rows/second
Looking for ways to improve throughput using OpenQuery/OpenResultSet, to match SSIS throughput. There is probably some buffer/flag somewhere that allows to achieve the same?
Please advise...
Thank you!
--Alex
There is probably some buffer/flag somewhere that allows to achieve the same?
Probably looking for the FetchSize parameter
FetchSize - specifies the number of rows the provider will fetch at a
time (fetch array). It must be set on the basis of data size and the
response time of the network. If the value is set too high, then this
could result in more wait time during the execution of the query. If
the value is set too low, then this could result in many more round
trips to the database. Valid values are 1 to 429,496, and 296. The
default is 100.
eg
exec sp_addlinkedserver N'MyOracle', 'Oracle', 'ORAOLEDB.Oracle', N'//172.16.8.119/xe', N'FetchSize=2000', ''
See, eg https://blogs.msdn.microsoft.com/dbrowne/2013/10/02/creating-a-linked-server-for-oracle-in-64bit-sql-server/
I think there are many way to enhance the performance on the INSERT query, I suggest reading the following article to get more information about data loading performance.
The Data Loading Performance Guide
There are one method you can try which is minimizing the logging by using clustered index. check the link below for more information:
New update on minimal logging for SQL Server 2008
I've created a linked server for an Access database from MSSQL that takes a very long time to return rows. I'm using SQL Server 2005 and the Access database is 2003. A select statement in SSMS of 8 columns and 80,000 rows takes 60s to run.
I gave SQL authenticated credentials ('sa' user) when creating the linked server so I don't think it has to do with permissions, and I'm unsure of what the problem is. I get the exact same running time using OPENQUERY as when I don't. Any guidance to why a simple query would take so long to run is very much appreciated.
My query.
SELECT * FROM AccessDB12...AP
I have database connection to database DB1. The only thing I could do - execute any t-sql statements including using stored procedures. I want to export the specific table (or even the specific rows of specific table) to my local database. As you can read abve, DBs are on diffrent servers meaning no direct connection is possible. Therefore question: Is it possible to write query that returns the other query to execute on local server and get data? Also note, that table contains BLOBs. Thanks.
If you have SQL Server Management Studio, you can use the data import function on your local database to get the data. It works as long as you have Read/Select access on the tables you are trying to copy.
If you have Visual Studio you can use the database tools in there to move data between two servers as long as you can connect to both from your workstation.
Needs Ultimate or Premium though:
http://msdn.microsoft.com/en-us/library/dd193261.aspx
RedGate has some usefull tools too:
http://www.red-gate.com/products/sql-development/sql-compare/features
Maybe you should ask at https://dba.stackexchange.com/ instead.
If you can login to the remote db (where you can only issue t-sql), you may create linked server on your local server to the remote and use it later directly in queries, like:
select * from [LinkedServerName].[DatabaseName].[SchemaName].[TableName]
Im creating a Stored Procedure on an 2008 SQL server.
I cant find how to retrieve the creation date of a given table in MS Access using SQL (or C# since it will be running inside a SSIS)
Besides the creation data, the time it was last modified would be also needed.
Any help?
Thanks a lot.
Might depend on the exact version of Access that created the database, but this information is found in the MSysObjects table (Access 97-2010)
I have written SQL statements (stored in a text document) that load data into a SQL Server database. These statements need to be repeated daily. Some of the statements use the NewId() function to populate a keyed field in the database, and this works fine.
While I'm in the process of writing an application to replicate these statements, I want to use Access queries and macros instead of copying and pasting queries into SQL Server, thus saving me time on a daily basis. All is working fine but I can't find any function that will replace the SQL Server NewId() function. Does one exist or is there a work around?
I'm using SQL Server 2005 and Access 2007.
On top of matt's answer, you could simply use a pass-through query and just use your existing, working queries from MS Access.
A solution would be to insert the stguidgen() function in your code, as you can find it here: http://trigeminal.fmsinc.com/code/guids.bas https://web.archive.org/web/20190129105748/http://trigeminal.fmsinc.com/code/guids.bas
The only workaround I can think of would be to define the column in your access database of type "Replication ID" and make it an autonumber field. That will automatically generate a unique GUID for each row and you won't need to use newid() at all. In SQL server, you would just make the default value for the column "newid()".
Again, there seems to be confusion here.
If I'm understanding correctly:
You have an Access front end.
You have a SQL Server 2005 back end.
What you need is the ability to generate the GUID in the SQL Server table. So, answers taht suggest adding an AutoNumber field of type ReplicationID in Access aren't going to help, as the table isn't a Jet table, but a SQL Server table.
The SQL can certainly be executed as a passthrough query, which will hand off everything to the SQL Server for processing, but I wonder why there isn't a default value for this field in SQL Server? Can SQL Server 2005 tables not have NewId() as the default value? Or is there some other method for having a field populate with a new GUID? I seem to recall something about using GUIDs and marking them "not for replication" (I don't have access to a SQL Server right at the moment to look this up).
Seems to me it's better to let the database engine do this kind of thing, rather than executing a function in your SQL to do it, but perhaps someone can enlighten me on why I'm wrong on that.