What's new in greenplum database 4.2.2

posted Apr 28, 2017, 4:46 PM by Sachchida Ojha
Greenplum Database 4.2.2 includes the following features and improvements:

1. Unlimited sub-transactions
4.2.2 removes the limit of 100 subtransactions per transaction.

2. Improved NFS backup to Data Domain
An optional direct I/O write path is available for DCA customers who want to control the amount of bandwidth used by the backup 
process. This feature can improve the reliability of the backup for some use cases.

3. Inverse distribution functions
Inverse distribution functions are a type of cumulative distribution function used in probability theory and statistics. 4.2.2 provides three new functions that take advantage of 
underlying inverse distribution algorithms:

a) Median returns the middle value.
b) percentile_disc() assumes a discrete distribution model.
c) percentile_cont() assumes a continuous distribution model.

Both percentile functions return an element from the set based on the percentile value and sort specification passed to the function.

4. Updatable cursors
A cursor is a database object that allows users and applications to manipulate data. In earlier versions of Greenplum Database, cursors were read-only after they were declared. In 4.2.2, you can update the set that cursors iterate over after declaration. This is important for integrating with some thirdparty software that assumes that updatable cursors are available, such as SAS.

5. Disk space monitoring
4.2.2 provides functionality to pro-actively monitor disk space capacity and to alert users when remaining capacity is low. You can configure two alert threshold levels 
(“warning” and “error”), send an alert by email or SNMP traps, and specify the frequency of. Greenplum Database sends an alert at the specified frequency when remaining disk 
capacity falls below configured levels.