I have a SQL Server 2012 database which currently used as a transactional database and reporting database. The application reads/writes into the same database and the reports are also generated against the same database.
Due to some performance issue, I have decided to maintain the two copies of the database. One will be a transactional database which will be accessed by the application. The other database will be the exact copy of the transactional database and it will only be used by the reporting service.
Following are the requirements:
The reporting database should be synched with transactional database in every one hour. That is, the reporting database can have stale data for maximum of 1 hour.
It must be read-only database.
The main intension is NOT recovery or availability.
I am not sure which strategy, transactional log shipping, mirroring or replication, will be best suited in my case. Also if I do the synch operation more frequently (say in every 10 minutes), will there be any impact on the transactional database or the reporting service?
Thanks
I strongly recommend you to use a standby database in readonly state. And every 15 minutes your sqlserveragent has a scheduled job to: a) generate a new .trn logfile within main db, and b) restore it into standby one(your reports db). The only issue is: using this technique your session will be disconnected while agent restores the .trn logfile. But if you can stop the restore job, run your reports and then reactivate it, there is no problem. Seems to be exactly what you need. Or if your reports are fast to run, probably will not be disconnected...if im not wrong restore job can also be configured to wait opened session to finish or to close it. I can check it this last doubt for you tomorrow if you don't find..
Once it is running in the same sql server instance, you don't have to worry about extra licensing...
Related
I'm building a monitoring tool which analyzes information in some sql tables and creates some charts and alerts based on some configurable criterias. However the underlying application is now getting some errors. I think it's because my queries are rather intensive on the tables which causes them to be locked for some amount of time and my idea of a work around is to synchronize the tables to a monitoring database and do my operations there.
Do you have any other ideas? And if I do the sync, whats the best way of syncing tables in SQL server? I prefer if the sync is as close to real-time as possible.
If you are running SQL Server 2008 R2 or above, Transactional Replication is usually a good fit for this type of scenarios and can support near real time synchronization. Here are few links to get familiar with Replication
Overview of replication
Use of replication for data warehousing and reporting applications.
The other solution is to Log ship the transactional database to reporting database.But
Log shipping is asynchronous operation, so the state of data in reporting database will be behind that of the data in transactional database.
You need to log ship the entire database even if you end up using only couple of tables.
The reporting database is not available when it is restoring from the transactional database.
so that would not match to your requirements.
Please advise what suits my problem better. I have a highload web app hosted on the same server where SQL server is hosted. I also have SQL Service reporting running on the same server, generating user reports.
So my server basically works on top of disk read/write speed. I'm going to get another server and install there another SQL server in order to host SSRS there. So my criteria is to get as fresh data as it possible.
I've looked a couple of solution, currently I do make backup via jobs, copy it to second server and restore it there, also via jobs. But that's not the best solution.
All replication mechanism(transaction, merge, snapshot) affect publisher database by locking it's table, what is unacceptable for me.
So I wonder is there any possibility to create a replica with read only access, that would be synced periodically not affecting main db? I would put all report load to that replica and make my primary db be used only by web app.
What solution might suit my problem? As I'm not a DBA, I'd start investigating that direction. Thanks.
Transactional Replication is typically used to off-load reporting to another server/instance and can be near real-time in a best case scenario. The benefit of Transactional Replication is you can place different indexes on the subscriber(s) to optimize reporting. You can also choose to replicate only a portion of the data if only a subset is needed for reporting.
The only time locking occurs with Transactional Replication is when you generate a snapshot. With concurrent snapshot processing, which is the default for Transactional Replication, the shared locks are only held for a short period of time, so users are able to continue working uninterrupted. Either way, this shouldn't be an issue since you'll likely be generating the snapshot during a period of low user activity anyway.
I have a online Database which will be updated Daily from various Sources.
I need to have a local Database with some tables from Server Database which have to check for any changes or new rows in tables in server and update the local Database for particular Intervals of Time. How can I Achieve this???
You may want to look into SQL Server Replication.
Replication will manage the data synchronization between the two copies of your database. You can configure replication for any tables in the database, including all tables. Replication will take care of checking for updates, adds and deletes from the Server Database and transfer the changes to the local database.
You can setup replication to update the local database at near-real-time or you can schedule periodic updates.
Replication is a high-maintenance solution. It's designed to maintain two copies of the same database with significant reliability. This makes replication a good solution when you must avoid data problems or recover from problems with little to no data loss.
If you don't require the high-maintenance solution, then SQL Server Integration Services (SSIS) may be a good alternative. With SSIS, you develop the data transfer and data management solution. Along with managing data problems, you design the solution to identify data adds, deletes and updates.
We have a client that currently has a large busy database that they back up using database mirroring. As part of a reporting requirement we need to use some of the data stored in the database to run reports against but we cannot access the data directly.
Is it possible for us to run transaction replication on that server to get our data while it is running database mirroring at the same time?
Thanks.
Yes it's possible to run transaction log shipping at the same time you are running mirroring. It is also possible to bring the secondary server up in a "Read Only" mode rather than "Standby" for the specific purpose of allowing you to run reports on the second server.
I'm interested in hearing people's thoughts about the pros and cons of database mirroring vs. log shipping in this scenario: we need to setup a database backup situation wherein there is exactly one secondary server that need not automatically pick up when the primary fails. Recovering and starting with the secondary should not have to take too long though.
Mirroring
Database mirroring is limited to only two servers.
Mirroring with a Witness Server allows for High Availability and automatic fail over.
You can configure your DSN string to have both mirrored servers in it so that when they switch you notice nothing.
While mirrored, your Mirrored Database cannot be accessed. It is in Synchronizing/Restoring mode.
Mirroring with SQL Server 2005 standard edition is not good for load balancing (see sentence above)
Log Shipping
You can log ship to multiple servers.
Log shipping is only as current as how often the job runs. If you ship logs every 15 minutes, the secondary server could be as far as 15 minutes. Making it more of a Warm Standby.
You can leave the database in read only mode while it is being updated. Good for reporting servers.
Good for disaster recovery
For backup purposes I would recommend Mirroring: it keeps an always up-to-date copy of your database with no hassle.. If you don't need automatic fail-over you need just two servers/instances. Note that High Performance mode is only available in the Enterprice (sp) edition!
Switching to the secondary database does take longer with log shipping, but it's not too bad. You'll have to manually copy any uncopied backup files, apply the transaction log backups to the secondary database, recover the secondary database, and change its role to primary. If the old primary databases accessible, you should back up its transaction log before beginning. Failing over with mirroring is somewhat simpler, and can be done automatically if you are using High Availability mode. Even when using High Performance mode, it's still a one statement operation.