<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE topic PUBLIC "-//OASIS//DTD DITA Composite//EN" "ditabase.dtd"><topicid="topic38"xml:lang="en"><titleid="in198679">Query Performance</title><abstract><shortdesc>Greenplum Database dynamically eliminates irrelevant partitions in a table and optimally allocates memory for different operators in a query.</shortdesc>These enhancements scan less data for a query, accelerate query processing, and support more concurrency.</abstract><body><ul><liid="in198681">Dynamic Partition Elimination<p>In Greenplum Database, values available only when a query runs are used to dynamically prune partitions, which improves query processing speed. Enable or disable dynamic partition elimination by setting the server configuration parameter <codeph>gp_dynamic_partition_pruning</codeph> to<codeph>ON</codeph> or <codeph>OFF</codeph>; it is <codeph>ON</codeph> by default.</p></li><liid="in198822">Memory Optimizations<p>Greenplum Database allocates memory optimally for different operators in a query and frees and re-allocates memory during the stages of processing a query.</p></li></ul>
