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How to create a read only replica of SQL Server database?
If the amount of changes occurring on Publication are large and depending on the network latency, there will be commands accumulating in distribution database waiting for the log-reader agent to scan and send them to subscriber. Schema changes will require a new snapshot – which causes locking on publication database until the snapshot finishes.
What does it mean to have a readable secondary replica?
A readable secondary replica can be in either synchronous-commit availability mode, or asynchronous-commit availability mode. A readable secondary replica allows read-only access to all its secondary databases. However, readable secondary databases are not set to read-only.
Is the secondary availability group replica offline in SQL Server?
Beginning in SQL Server 2014 (12.x), readable secondary replicas can remain online even when the primary replica is offline due to user action or a failure. However, read-only routing does not work in this situation because the availability group listener is offline as well.
Can You maintain a replica in a mounted rather than read-only state?
Redo log data is always transmitted in parallel from the primary database to all of its read replicas. No. PostgreSQL has a single process handling replication. Yes. Redo log data is always transmitted in parallel from the primary database to all of its read replicas. Can you maintain a replica in a mounted rather than a read-only state?
Is it free to replicate a SQL Server database?
That said – Replication isn’t “free” – you need to administer and monitor it and a poor setup could make performance problems worse. You should learn about the best options for performance and the best setup for performance and keep that in mind and keep your replication environment monitored.
Can a secondary database be used as read only?
The good thing about logshipping is that you can have the secondary database as read-only in STANDBY mode. You can delay the restore of log backups on secondary. Note: that if you use logshipping with STANDBY option, the secondary database cannot be on a higher version of sql server than a primary. Mike as a good point on Transaction Replication.
Can a schema change cause a replication problem?
Schema changes will require a new snapshot – which causes locking on publication database until the snapshot finishes. Also, replication of the entire database as opposed to a subset of data (selected tables, SPs, etc) often leads to problems related to its maintenance.