I need to set up this scenario:
A SQL Server 2005 database will create a transactional replication subscription from another database to populate a set of lookup tables. These lookup tables will then be published as a merge replication publication to the client's SQL Server Mobile.
I remember seeing a similar scenario defined in the SQL Server Books Online somewhere, but I was unable to find the link anymore. I hope someone can help me find it, or otherwise point me to any other similar links.
Okay, I managed to get the answers I needed at the MSDN SQL Server Replication forum.
The article I was looking for is called: Republishing Data.
Apparently, it is located within "Advanced Replication Features and Internals" of the "Configuring and Maintaining Replications" section. It's a little non-obvious, so I spent most of my time looking in the "Replicating Data Between a Server and Clients" section, instead of there. Good to know, as there seems to be a number of other special scenarios worth looking at in there.
I do not get the interest of having a transactional replication to generate lookup tables. Such tables are not made to be updated from the client side, so why do you want to combine transactional + merge replication when you don't have the data modified by the subscribers?
Maybe the original scenario is not clear, so let me clarify.
The database where the original lookup tables are located either remotely with bad network connection, or operated under heavy load. This approach was suggested so that the lookup tables are replicated to another database which all merge replication with the clients will be performed.
Of course, it may not be the most appropriate approach to our problem, so if anyone has a better idea, we'll like to hear them.
Still, the main reason for this question is to find an article I previously found (but stupidly did not bookmarked) which described our scenario quite well. Any possible leads to this article (title, author, similar topics, etc) are definitely appreciated.
Related
We have several database servers at my work, most of which I have access too. In one server there is a database within that contains a table I want to look at but don't "need" to look at. It's more curiosity, would any one be able to know or be notified if I looked at this table?
Thanks
I am assuming you are referring to SQL Server. Refer here for a better understanding of how easy it is to track such activities.
Auditing is one of the basic capabilities of any database server. If there is a business need for the DBAs to monitor access to any specific database / table, chances are they might already be logging it. Better ask your DBAs about it if you are really interested in learning about that table.
I have set up an Azure database instance which supposedly replicates into a 'read only' secondary database using standard geo-replication. In the Azure portal I can see the status of the replication is 'online' and 'Secondary type' is 'Offline', which appears to be normal.
My question is, is there a way for me to see the actual contents of the secondary database, to ensure the replication is actually working as planned?
I cannot 'Manage' the database in the portal. I can connect to the instance in SQL Management Studio, where I can see the database but expanding tables / stored procedures shows nothing (a bit like connecting to a secure database using the non-secure connection string). I am also not able to run any queries against it as it gives me 'Connection to an offline secondary database is not allowed.'
I've searched this site an did a web search for an answer but can't seem to find one. Am I supposed to blindly rely on the fact that Azure is perfoming the replication correctly (with no way to double-check), or am I missing something here?
Many thanks in advance for any light you are able to shed on this.
Standard Geo-Replicated Secondary DBs are offline copies that do not accept client connections (so there is no way to query the data directly). If you need a readable Geo-Replicated Secondary then you must use the Active Geo-Replication available for Premium DBs.
Even though you can't query Standard Geo-Replicated DBs directly, you can use the DMVs in the Master to determine if the continuous copy is working correctly.
On the Master try the following:
SELECT * FROM sys.dm_database_copies
SELECT * FROM sys.dm_Continuous_copy_status
I hope this helps!
For more information about Standard Geo-Replication, Active Geo-Replication Or Checking the activity of continuous copy use the following links.
Standard Geo-Replication: https://msdn.microsoft.com/en-us/library/azure/Dn758204.aspx
Active Geo-Replication: https://msdn.microsoft.com/en-us/library/azure/dn741339.aspx
Continuous Copy DMV Blog: http://www.sqlservercentral.com/blogs/pie-in-the-sky/2014/12/25/monitoring-geo-replication-in-sql-azure-using-dmvs/
I tried to repro your situation and I think I understand the confusion.
When the Secondary Type = "Offline" then it is a standard Geo-Replicated Secondary. The Primary Databases page is confusing, but when you click on the link to the secondary should show that it is offline.
As far as understanding if the continuous copy is working, run the script below against the Primary (I was mistaken last time, Sorry).
SELECT * FROM sys.dm_Continuous_copy_status
You should see the linked server, database, and Replication State.
As before if you need to read from your secondary, you will have to created a premium active-Geo Replicated Secondary.
Hope This helps!
I'm designing a system that checks a given website for any security vulnerabilities. The system includes a client (firefox plugin) and a server. The server does all the scanning while the client just relays that info to the user. If a website is dangerous, it is blacklisted; otherwise whitelisted.
The system must hypothetically be able to handle several thousands of requests and updates to the database simultaneously.
Although the database is expected to have a very simple structure, I am still considering using NoSQL because my understanding is that it can handle a greater amount of queries. Is this true? Which db technology is better suited for my system?
I suggest a NoSQL database.
In fact I've been working with two databases in the last weeks, and searching on internet I found the differences between a NoSQL an a SQL database.
Pratically, you should use a NoSQL db if you have a lot of data to query. Remind that it's not sure the data recovery in case of a db disaster.
Instead, use a SQL database if your data MUST be permanent, and you can't lose it. But query times will be longer, so it's not suggested if you have tons of data.
I understood, from what you wrote, that you need lot of queries and you "can lose" the data (if you lose a website of the list, you'll just need to re-check it, right?).
So I suggest you to go for a NoSQL db (I worked with MongoDb, it is the most famous worl-wide).
If you consider NoSQL Databases you have to analyze your data to get the right Database.
For your use case I think you should look at document databases (like MongoDB) or, if you want really high performance, a key-value Database like Redis or Riak.
With Key-Value databases you can only use the key to find the data you want.
With document databases you still have some kind of querys to find the data.
For further information look at: http://nosql-database.org/
How to get the code of all replication definitions of a Sybase server?
If possible and since I'm new to this, give me a little explanation on them as well.
Much of the information about your replication system can be found using the various help functions in the RSSD/ERSSD. The specific commands will vary somewhat based on the kind of Replication you are using (Warm Standby, Function String, Table, Procedure, mixed).
rs_helpdb [ dataserver, database ]: Shows all databases known by the RSSD. If you specify dataserver/datbase, it will only show information for that connection. Output lists Server/Database, rep dbid, primary RS, errorclass, repserver errorclass, function class and status.
rs_helprepdb: Shows replicate databases that have subscriptions to primary data in the current RS, or shows the specified DS/DB.
Other commands that will help:
rs_helprep Displays information about replication definitions
rs_helpsub Displays information about subscriptions
rs_helpreptable Displays information about replication definitions created against a primary table.
rs_helppub Displays information about publications.
rs_helppubsub Displays information about publication subscriptions and article subscriptions.
rs_helpdbrep Displays information about database replication definitions associated with the current Replication Server
rs_helpdbsub Displays information about database subscriptions associated with the replicate data server.
These commands all pull information from the tables in the RSSD, so you can also poke around the RSSD to find the information you are looking for. Here is the RS table diagram to help.
Also, if you are going to do any regular replication work, I highly recommend Rob Verschoors The Complete Sybase Replication Server Quick Reference Guide (www.sypron.nl), as it has >90% of what you need to create and manage a Sybase rep environment.
you can use Replication Monitoring Services (RMS)
Various stored procedures and shell scripts for reverse-engineering RepServer objects can be downloaded from http://repserver.codexchange.sybase.com (link 'repserver', folder Admin Tools/Scripts)
PowerDesigner provides reverse-engineering but might require a special license
I am working on a database for a monitoring application, and I got all the business logic sorted out. It's all well and good, but one of the requirements is that the monitoring data is to be completely stand-alone.
I'm using a local database on my web-server to do some event handling and caching notifications. Since there is one event row per system on my monitor database, it's easy to just get the id and query the monitoring data if needed, and since this is something only my web server uses, integrity can be enforced externally. Querying is not an issue either, as all the relationships are one-to-one so it's very straight forward.
My problem comes with user administration. My original plan had it on yet another database (to meet the requirement of leaving the monitoring database alone), but I don't think I was thinking straight when I thought of that. I can get all the ids of the systems a user has access to easily enough, but how then can I efficiently pass that to a query on the other database? Is there a solution for this? Making a chain of ors seems like an ugly and buggy solution.
I assume this kind of problem isn't that uncommon? What do most developers do when they have to integrate different database servers? In any case, I am leaning towards just talking my employer into putting user administration data in the same database, but I want to know if this kind of thing can be done.
There are a few ways to accomplish what you are after:
Use concepts like linked servers (SQL Server - http://msdn.microsoft.com/en-us/library/ms188279.aspx)
Individual connection strings within your front end driving the database layer
Use things like replication to duplicate the data
Also, the concept of multiple databases on a single database server instance seems like it would not be violating your business requirements, and I investigate that as a starting point, with the details you have given.