A short blog to enable write-able mongo_fdw extension in PostgreSQL 9.4. PostgreSQL provides a powerful feature called Foreign Data Wrappers (FDW), which allows DBAs to connect to other data sources from within PostgreSQL. Foreign Data Wrapper implementation is based on SQL/MED, that’s supported from PostgreSQL 9.1 version onwards, which means we can now access remote database through PostgreSQL seamlessly. Today we have variety of FDW’s available, in this blog, we will be compiling a latest version of write-able FDW “mongo_fdw” to access MongoDB.
This blog is about compiling pg_repack extension on binary format of PostgreSQL installation. Most of you know, pg_repack extension is one of well known PostgreSQL extensions, its especially used for reclaiming space[bloats] ONLINE without holding an EXCLUSIVE LOCK on Tables/Indexes.
To enable pg_repack extension in PostgreSQL database, it should be compiled from sources. Its quite easy and simple to compile from source on any installed variants(source,rpm,binary) of PostgreSQL, however its slightly different if it is with binary format of PostgreSQL [One Click Installer] as they are pre-built binary bundle with dependency libraries.
In PostgreSQL high availability(Streaming Replication/Hot Standby), one of the thing require human interference and has no automation, that is in the event of master database crash; initiating failover procedure(trigger file creation or pg_ctl promote command) on the standby. Because in core of PostgreSQL there’s no such built-in functionality to identify a failure of master and notify the standby. Thus, we require some automated tools to take over manual failover work or we have to dive into scripting land for writing our own script to do it.
This post educates sophisticated DBA’s on how to setup graceful Switchover and Switchback environment in PostgreSQL high availability. Firstly, thanks to patch authors Heikkiand Fujii for making Switchover/Switchback easier in PostgreSQL 9.3.(Pardom me if I missed other names).
Let me attempt to illustrate it in short prior to these patches, all of you know Standby’s are critical components in achieving fast and safe disaster recovery. In PostgreSQL, recovery concept majorly deals with timelines to identify a series of WAL segments before and after the PITR or promotion of Standby to avoid overlapping of WAL segments.
Every new release of PostgreSQL comes with a packed of exciting features. To benefit new features, database server should be upgraded. Choosing traditional upgrade paths like pg_dump/pg_restore or pg_upgrade requires a significant downtime of application. Today, if you are looking for minimum downtime upgrade path among major PostgreSQL versions with perfect rollback plan, then it will be accomplished by asynchronous Slony-I replication. Since Slony-I (know more about it here) has the capability to replicate between different PostgreSQL versions,OS and bit architectures easily, so upgrades are doable without requiring a substantial downtime.