Minimalistic Oracle contains a collection of practical examples from my encounters with Oracle technologies. When relevant, I also write about other technologies, like Linux or PostgreSQL. Many of the posts starts with "how to" since they derive directly from my own personal experience. My goal is to provide simple examples, so that they can be easily adapted to other situations.
Thursday, May 2, 2019
What exactly is meant by "global statistics" on a partitioned table?
From the whitepaper "Understanding Optimizer Statistics":
"When dealing with partitioned tables the Optimizer relies on both the statistics for the entire table
(global statistics) as well as the statistics for the individual partitions (partition statistics) to select a
good execution plan for a SQL statement. If the query needs to access only a single partition, the
Optimizer uses only the statistics of the accessed partition. If the query access more than one partition,
it uses a combination of global and partition statistics."
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