I have a vendor SQL Server 2008 db which I am trying to add-on to with additional tables etc. to customize for my order processing .Net 3.5 site. The vendor db should not be altered. However I need to record the current Order Status which is not included in the vendor's db.
Currently I'm using a VIEW with a CASE to get the Status based on data in the Orders table. To improve performance I'd like to create a new Status table with OrderID & Current_Status.
To keep the Status table up-to-date is there an alternative to frequently running a script which will look at all Orders and update the Status table accordingly?
Creating a job or other polling-type solution is probably fine if the load imposed by the query is not high and if you can tolerate some delay before the data is synched.
If you can tolerate at least some delay, but the query to check the table is extensive, or if you have several tables you want to perform this operation on, you could also use Change Tracking, since you have SQL Server 2008.
Here's a link on how to use it.
Create a SSIS job to check orders and update the status table. And schedule it to run hourly/daily(as per your requirement). Creating SSIS jobs will not affect any of your vender process or objects.
If performance is your worry, how about an indexed view?
Related
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I need to update two tables in SQL [closed]
Closed 8 years ago.
I need to update one table from one database to another table on another database. This will need to be run once a day. Both tables are the same structure.
One database is called pvc_rds and the other is called kiosk. The table is REC_Materials. There is a column called sid that is unique. Both these live on the same SQL Server 2008.
I am new to this so any help would be appreciated. Thanks
The simple answer is to create a scheduled job, which contains a step that queries the source server (source database) and insert into the target database. However, you must use the complete name of the object, as described here: http://technet.microsoft.com/en-us/library/ms187879(v=sql.105).aspx
The more complicated answer depends on your overall goal. Is the source database, a transaction database and the target database the reporting database? In which case, is your goal to replicate the data using transaction or merge replication?
Use (at least) a three-part identifier.
The complete name of an object is made up of four identifiers: the server name, database name, schema name, and object name. They appear in the following format:
server_name.[database_name].[schema_name].object_name
In your case, this would simply translate to (assuming the dbo schema for your tables) :
UPDATE pvc_rds.dbo.REC_Materials
FROM pvc_rds.dbo.REC_Materials
INNER JOIN kiosk.dbo.REC_Materials
ON pvc_rds.dbo.REC_Materials.sid = kiosk.dbo.REC_Materials.sid
in order to synchronise existing records present in both databases. You can expand on this to remove records that shouldn't be there anymore and add any new records. You can save that process into a job, and make it run everyday by scheduling it.
I have 13 SQL databases some 2005 others 2008, on a VPN. I'd like to take all of the data from the "Employees" table on each database and make it a view at each location. I would then like to publish these views to 1 database on another server, all in one table marking where each came from within the origninal databases. For example the database where all the information goes to would look like this:
User Name Location
bik Bob K 1
JS John S 2
Etc.
Any help is appreciated.
I assume you want the data on the final server to be viewable, but not modifiable, and to reflect changes made to the source databases?
This would probably not perform all that well, but one do-it-yourself-way to do it would be the following (disclaimer: I haven't tried doing this myself):
Set up all the source servers as linked servers on the final server.
Create a view in this form:
SELECT *, 1 as Location
FROM [Linked Server 1].Database1.dbo.Table1
UNION ALL
SELECT *, 2 as Location
FROM [Linked Server 2].Database2.dbo.Table2
... etc ....
You might want to read this documentation on distributed queries, if you haven't already.
I believe it's also possible to use SSIS as the source of a distributed query, but a quick scan through the documentation didn't find anything about it. I mention that because SSIS would make pulling and transforming data from disaparate data sources very easy, and if you could use the final recordset as a data source, you could use an SSIS package as the backend to your view. However, again, performance would probably require considerable tuning.
If the queries don't have to be real time you could look into using SQL Server Integration Services (SSIS) to pull in the data to a local DB. you could schedule the job to run hourly/daily/weekly..
I need to pull a large amount of data from various tables across a line that has very low bandwidth. I need to minimize the amount of data that gets sent too and fro.
On that side is a Sybase database, on this side SQL Server 2008.
What I need is to pull all the tables from the Sybase database that have to do with this office. Lets say I have the following tables as an example:
Farm
Tree
Branch
etc.
(one farm has many trees, one tree has many branches etc.)
Lets say the "Farm" table has a field called "CountryID", and I only want the data for where CountryID=12. The actual table structures I am looking at are very complex (and I am also not very familiar with them) so I want to try to keep the queries simple.
So I am thinking of setting up a series of views:
CREATE VIEW vw_Farm AS
SELECT * from Farm where CountryID=12
CREATE VIEW vw_Tree AS
SELECT * from Tree where FarmID in (SELECT FarmID FROM vw_Farm)
CREATE VIEW vw_Branch AS
SELECT * from Tree where BranchID in (SELECT BranchID FROM vw_Branch)
etc.
To then pull the actual data across I would then do:
SELECT * from vw_Farm into localDb.Farm
SELECT * from vw_Tree into localDb.Tree
SELECT * from vw_Branch into localDb.Branch
etc.
Simple enough to set up. I am wondering how this will perform though? Will it perform all the SELECT statements on the Sybase side and then just send back the result? Also, since this will be an iterative process, is it possible to index the views for subsequent calls?
Any other optimisation suggestions would also be welcome!
Thanks
Karl
EDIT: Just to clarify, the views will be set up in SQL Server. I am using a linked server using Sybase ASE to set up those views. What is worrying me in particular is whether the fact that the view is in SQL Server on this side and not on Sybase on that side will mean that for each iteration the data from the preceeing view will get pulled across to SQL Server first before the calculations get executed. I want Sybase to do all the calcs and just pass the results across.
It's difficult to be certain without testing, but my somewhat-relevant experience (using linked servers to platforms other than Sybase, and on SQL Server 2005) has been that using subqueries (such as your code for vw_Tree and vw_Branch) more or less guarantees that SQL Server will pull all the data for the outer table into a local temp table, then match it to the results of the inner query.
The problem is that SQL Server has no access to the linked server's table statistics, so can make no meaningful decisions about how to optimise the query.
If you want to be sure to have the work done on the Sybase server, your best bet will be to write code (could be views or stored procedures) on the Sybase side and reference them from SQL Server.
Linked server connections are, in my experience, not particularly resilient over flaky networks. If it's available, you could consider using Integration Services rather than linked-server queries - but even that may not be much better. You may need to consider falling back on moving text files with robocopy and bcp.
I am working with sensitive/private files stored in SQL Server as VarBinary(MAX). Is there a way to tell the database or nHibernate to nullify the column after a period of time after its creation.
Make sure to put a timestamp column on the table, then set up a SQL Scheduled Job with a query to delete those rows periodically based on that time.
Absolutely not
Imagine the fun when SQL Server decides to change data apparently on it's own because the code monkey fluffed setting up whatever mechanism would be used...
You could (off top of my head):
Encrypt the columns
Schedule a clean up (SQL Agent job, a config table)
Don't use SQL Server for the files themselves, just store paths/links
I need to quickly implement a read-only database containing data pulled from two identically structured live databases.
The live dbs are actually company dbs from a Dynamics accounting system so I'm happy for any Dynamics specific advice but this is mostly a SQL question. It's a fairly old version of Dynamics from before Great Plains was acquired by Microsoft. This is on SQL Server 2000.
We have reports and applications which access the Dynamics data. These apps are designed to look at one company db. Now we need to add another. It's appropriate that most of these reports and apps see combined data. They don't really care which company an order or invoice exists in. They only look at a small number of the tables.
It seems to me that the simplest solution is to create a reports only db with combined data. Preferably, we need an efficient way to update this db with changes several times a day.
I'm a developer, not a db expert but here's my plan:
Create the combined reporting db with the required tables initially with the same table structure as the live dbs.
All Dynamics tables seem to have an int identity column called DEX_ROW_ID. I'm not sure what it's used for, (it's not indexed) but that seems like the obvious generic way to uniquely identify rows. On the reporting db I will change it to a normal int (not an identity). I will create a unique index on DEX_ROW_ID in all dbs.
Dynamics does not have timestamps so I will add a timestamp column to tables in the live dbs and a corresponding binary(8) column in the reporting db. I'm assuming and hoping that Dynamics won't be upset by the additional index and column.
Add an int CompanyId column to the reporting db tables and add it to the end of any unique indexes. Most data will be naturally unique even without that. ie, order and invoice numbers etc will be different for the two live dbs. We may need to make some minor changes to the applications but I'm not expecting to do much other than point them to the new reporting db.
Assuming my reporting db is called Reports, the live dbs are Live1 and Live2, the timestamp column is called TS and all dbs are on the same server ... here's my first attempt at an update script for copying the changes in one table called MyTable in Live1 to the reporting db.
USE Reports
CREATE TABLE #Changes
(
ReportId int,
LiveId int
)
/* Collect in a temp table the ids or rows which have been deleted or changed
in the live db L.DEX_ROW_ID will be null if the row has been deleted */
INSERT INTO #Changes
SELECT R.DEX_ROW_ID, L.DEX_ROW_ID
FROM MyTable R LEFT OUTER JOIN Live1.dbo.MyTable L ON L.DEX_ROW_ID = R.DEX_ROW_ID
WHERE R.CompanyId = 1 AND L.DEX_ROW_ID IS NULL OR L.TS <> R.TS
/* Delete rows that have been deleted or changed on the live db
I wonder if using join syntax would run better than the subquery. */
DELETE FROM MyTable
WHERE CompanyId = 1 AND DEX_ROW_ID IN (SELECT ReportId FROM #Changes)
/* Recopy rows that have changed in the live db */
INSERT INTO MyTable
SELECT 1 AS CompanyId, * FROM Live1.dbo.MyTable L
WHERE L.DEX_ROW_ID IN (SELECT ReportId FROM #Changes WHERE LiveId IS NOT NULL)
/* Copy the rows that are new in the live db */
INSERT INTO MyTable
SELECT 1 AS CompanyId, * FROM Live1.dbo.MyTable
WHERE DEX_ROW_ID > (SELECT MAX(DEX_ROW_ID) FROM MyTable WHERE CompanyId = 1)
Then do the same for the Live2 db. Repeat for every table in Reports. I know I should use a parameter #CompanyId instead of the literal but I can't do that for the live db name some I might generate these dynamically with a C# program or something.
I'm looking for any advice, suggestions or critique on what I'm doing here. I know it won't be atomic. Things could be happening on the live db while this script runs. I think we can live with that. We'll probably do a full copy either nightly or weekly when nothing is happening on the live dbs.
We need to favor performance over elegance or perfection. Some initial testing has the first query with the TS comparisons running at about 30 seconds for the biggest table so I'm optimistic that this is going to work but I'd also like to know if I'm missing something obvious or not seeing the forest for the trees.
We don't really want to deal with log files on the reporting db. Can we just set that to simple recovery model and forget about logs?
Thanks
I think there are a couple open questions here.
Do you need these reports to be near-real-time? Or is this this sort of reporting that could live with daily updates? But assume you need up-to-the-minute data.
Have you considered querying the databases directly and merging the data per-report on the fly? You'll have to do a lot of reporting to duplicate the effort that's going to go into designing, creating, and supporting a real-time merged replicated database.
Thirty seconds is (IMHO) unacceptable for any single query against a production database. There could be any number of tuning-related reasons for taking this long, but it at least means you're going to need serious professional SQL Server optimization resources (i.e. people). And if this is a problem for the queries for reports, it doesn't bode well for the queries to maintain a separate database for reporting.
Tuck into the back of your mind the consideration that, if you need to consolidate to a single database, it's worth considering whether you should make it an OLAP database rather than a mirror. The mirror will be quicker and easier, but the OLAP would be far more flexible and powerful in the long term; and it might be well to go the whole way from the beginning.
The last thing I'd want to do is write a custom update script. Try these bulletproof methods first:
Let's hope your production databases are backed up. Restore those backups every night to the reporting server. You can automate restores with the RESTORE command, which will work with a file on a network server.
Use SQL Server replication to push data from the live servers to the backend.
Schedule a DTS package every night to import the entire production database.
This might seem like brute force. But since you're copying a 2000-era database, brute force cannot be a problem with today's hardware. As an added advantage, these methods can be supported by a sysadmin instead of a developer.
Method 1 has the added added advantage of serving as backup verification. :)