I was trying to solve this specific issue:
I needed a single query that will retrieve the table in the entire instance with most rows. (I would run it in 20 sql instances, all sql 2016.)
It would be run in production so; ideally, it should not be a resource-consuming SP…
All other solutions I saw were… either for sql 2005, or they just retrieved it for a single database.
Related
I have a single SQL query that I need to run against ~25 different databases- each residing on a separate SQL server on the network. The query will run from a single central SQL server management studio, and the 24 other SQL server instances are linked. I have the query I need, and I tested that it works- however the goal is to create a script that queries each of the 25 separate SQL instances.
Instead of writing the query out 25 separate times within the script, I'm wondering if there's a way to utilize the single block of code to query each of the linked instances using an array, variables, DO/WHILE, a function or any other method.
Here's the query:
SET NOCOUNT ON
PRINT 'local server';
SELECT isc.ini_schema_name[Device], count(*) [Count]
FROM pharos.dbo.edi_pharos_stations eps, pharos.dbo.ini_schemas isc
WHERE eps.ini_schema_id = isc.ini_schema_id
GROUP BY isc.ini_schema_id, isc.ini_schema_name
For the purpose of this example, if I were to utilize the less-graceful approach of writing out the block of code 24 more times, this would be the next query in the script (to query SQL server hostnamed pharos90-2008).
PRINT 'Pharos90-2008';
SELECT isc.ini_schema_name[Device], count(*) [Count]
FROM [pharos90-2008].pharos.dbo.edi_pharos_stations eps, [pharos90-2008].pharos.dbo.ini_schemas isc
WHERE eps.ini_schema_id = isc.ini_schema_id
GROUP BY isc.ini_schema_id, isc.ini_schema_name
As you can see, the query / code is exactly the same except for the fact that it is referencing a separate linked SQL Server (query being run from a central SQL Server Management Studio).
The ultimate goal is to output the queried data for each SQL instance to a single .txt file; format being, print the name of each particular SQL server followed by the corresponding queried data.
Any advice as to how one would accomplish such a task?
Thanks in advance.
Well, one way would be to create a cursor to iterate all of your linked servers. (You can find linked servers like this...)
SELECT * FROM sys.servers WHERE is_linked = 1
Then, you could use the undocumented sp_MSForEachDB stored procedure to run a dynamic version of your query (changing the server on each iteration) on each database in the cursor's current server. If you search for sp_MSForEachDB you can find plenty of information. But here's one link to save time.
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.
I have had an odd error I cannot explain. Basically, I am running a query to my SQL database using excel and am having non-existent data pop up when it comes to a very particular order in my database.
Here is a simple query surrounding this order:
select * from OR200100 where OR200100.OR20001='0000793605'
Here is the output in EXCEL
And here is the same output in SQL
what is happening here? How could the same query generate 2 different results?
Run SQL Server Profiler against the database if you can, then compare the output to the sql query that you are running in ssms.
OK, so it's SQL Server then, that's important because different SQL products can have very different idiosyncrasies and controls.
The next things to check are these:
Is OR200100 a Table or a View? If it's a view then post it's code.
Are you using the same Login/account from both Excel and SSMS?
Are you sure that you are connecting to the same Server and Database? SSMS tells you what you are connected to, but client apps like Excel do not and it is very common for this type of problem to be caused by the app connecting to a Dev or QA version of the database. See here for some of the different ways that this can happen:
So I had a very similar problem, my query was grouping by week numbers. What I found was that one of the queries had set datefirst 5 set whilst the other didn't. I guess the key thing here is make sure, if you are using any SET operations in your ssms queries, these are identical to those in the Excel query string.
I have a PostgreSQL database that stores real-time data from sensors in a specific table (every 30sec).
What I want to do, is to get periodically the data from the remote PostgreSQL database (for instance every 30sec) and store them in SQL Server 2005 to manipulate them locally. I don't care about having the two databases with duplicate tables. Actually this is what I want to achieve!
So far, I have as Linked Server the PostgreSQL to SQL Server and I can query and retrieve the sensor data. However, I prefer to store them in my SQL Server for performance reasons.
Solution so far:
Make select openquery statements with the linked PostgreSQL and insert the results to my table in SQL Server. Repeat this periodically and store fresh data only (e.g. with a larger timestamp).
I assume that my proposed solution is not ideal. I want to know what are the best practices to achieve this synchronization between the two databases.
Thank you in advance!
If you don't want to write your own code(implementations) to do that you can use SymmetricDS to synch the table from postgreSQL to MSSQL .
i have a view that is using linked server to retrieve data from a remote server in SQL Server. On each time viewing the view, the results returned are vary. For example, 1st time execution may return 100 rows of records but on 2nd time of execution, rows returned are 120 rows. Any ideas what is the cause?
I have witnessed odd linked-server results that are a product of non-determinism written into the SQL itself, I.e. a TOP query written without an ORDER BY clause.
This problem, for example, where the chap had multiple non-unique foreign keys coming from a table source on the left hand side of a linked-server INNER JOIN, and wanted 10 rows from a remote sub-query to the right, where the end result was restricted to 10 rows itself, when it should have been greater than 10 rows.
Should definitely give your SQL a quick eye for such curiosities.
The data on the linked server changed between executions?
Is your SQL Server fully patched? SQL Server 2008 and 2005 both have bug fixes out related to incorrect query results from linked servers.
Here is one example:
969997 FIX: You receive an incorrect result when you query data from a linked server that is created by using an index OLE DB provider in SQL Server 2005 or in SQL Server 2008
Is the linked server also a SQL Server? If not, perhaps a buggy driver? I've seen odd results, for example, due to an old Informix ODBC driver. Are you able to run something akin to SQL Profiler on the linked server to see what command it's receiving?
I'm not sure what the answer is, but (assuming that your counts of 100 and 120 are accurate) can you not capture the data from the two runs and compare it? That might give you some clues as to what's going on. For example, is it completely different datat, or is it duplicate rows (in the 120 row batch).