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Oracle 12.2 New Features : Convert Non Partitioned Table to Partitioned Table using ALTER

In earlier versions of Oracle, when one want to convert a table to partition, one must use move or export/import method and rename it.

Now in 12.2 release we can use ALTER table command to convert the table into Partitioned Table. Here is sample command it is from the documentation excerpt,



12.2 New Features : Memory Management at PDB Level

Memory & Guaranteed BufferCache/Shared Pool can be allocated at PDB Level. From the white paper here it is

Well so far I haven’t seen any such need to keep a separate memory settings for each PDB as we […]

Oracle 12.2 New Features : Local UNDO and Flashback PDB Database


You can now flashback PDB database exclusively with Local UNDO enabled. In earlier versions, Oracle shares the undo tablespace for CDB and PDB’s and creates a common view for transaction and instance recovery done at all CDB and PDB level. With local undo , Oracle has to change this a bit, it has to […]

Oracle 12.2 New Features : SQLPLUS Enhancements

In 12.2 release, one of the coolest things that every DBA would love is to get history in SQLPLUS :).

Now you can have history ON/OFF with SQLPLUS and see history



Some other features like, FAST OPTION -F flag to set the ARRAYSIZE PAGESIZE STATEMENTCACHE all […]

Oracle 12.2 New Features : Oracle Sharding on its Way

DBA’s , Oracle is coming with Sharding. The one killer feature that No-SQL databases claiming distributed processing with sharding aka a non-shared database storage.

Now with release 12.2 Oracle releasing Sharding feature, with new command “Create Sharded Table” and with a catalog schema, well hold on second , its basically distributed partitioning relied on partitioning […]

Oracle 12.2 New Features : Long Identifiers – What a relief

Oracle 12.2. is out and in Cloud first. 🙂

Out of all features one future must aware and important thing is long identifiers limitation relief , earlier any table or index cannot exceed more than 30 character length.

Not sure how many of you have face issues with character limit, but I was, and many […]

MongoDB for Oracle DBA’s Part 11 : Enabling Preferred Read on Standby (Secondary) Instances

As we know in ASM we can specificy the preferred read fail group to scatter the reads across the failgroups to reduce the read contention on single disk group. Similarly in MongoDB you can set to read the data from secondary servers i.e standby, In other words take this as active dataguard feature where you […]

MongoDB for Oracle DBA’s Part 10 : Switchover & Role Transition between Primary and Secondary

In MongoDB as like Oracle Dataguard switchover is possible to but in different way.

You can ask Primary to stepdown and let nodes elect a new primary in replicaset. This can be done using rs.stepDown() method.

Before stepping down primary, one must know the below

The procedure blocks all writes to primary while it runs […]

MongoDB for Oracle DBA’s Part 9 : Node Evictions – Losing a Shard

In the previous post we saw when a node in replicaset lost, the secondary nodes become a primary and all data is available.

In this post we will see what if , if a shard is completely lost. A picture looks like this.

As the data is distributed across the shards, if a […]

MongoDB for Oracle DBA’s Part 9 : Node Evictions

In MongoDB the high availability is called as basic availability, means in event a primary replicaset lost , the secondary can become primary with in that replicaset. But when the whole shard is down (including all nodes within that replicaset) then there is no High Availability, the data is partially available with respects to the […]