automatic data optimization

Automatic data optimization (ADO) is a component of Information Lifecycle Management (ILM) that automates the compression and movement of data between different tiers of storage within the database.

composite partitioning

Composite partitioning is a combination of the basic data distribution methods. After a table is partitioned by a data distribution method, then each partition is subdivided into subpartitions using the same or a different data distribution method.

degree of parallelism (DOP)

The degree of parallelism (DOP) is the number of parallel execution (PX) servers associated with a single operation.

distribution method (parallel execution)

A distribution method is the method by which data is sent, or redistributed, from one parallel execution (PX) server set to another.

hash partitioning

Hash partitioning maps data to partitions based on a hashing algorithm that Oracle applies to the partitioning key that you identify.

heat map

Heat map is a component of Information Lifecycle Management (ILM) that tracks data access at the segment-level and data modification at the segment and row level.

Information Lifecycle Management

Information Lifecycle Management (ILM) is a set of processes and policies for managing data throughout its useful life.

list partitioning

List partitioning maps rows to partitions by specifying a list of discrete values for the partitioning key in the description for each partition.

parallel execution (PX)

Parallel execution (PX) is the ability to apply multiple CPU and I/O resources to the execution of a single SQL statement with the use of multiple processes.

parallel execution server

The parallel execution (PX) servers are the individual processes that perform work in parallel on behalf of the initiating session.


Parallelism is breaking down a task so that many processes simultaneously do part of the work in a query, rather than one process doing all of the work.

partition pruning

Partition pruning occurs when the results of a query can be achieved by accessing a subset of partitions, rather than the entire table.


Partitioning is the process of subdividing objects, such as tables and indexes, into smaller and more manageable pieces.

partitioning key

The partitioning key consists of one or more columns that determine the partition where each row is stored.

query coordinator (QC)

The query coordinator (QC), or also called the parallel execution (PX) coordinator, is the session that initiates the parallel SQL statement.

range partitioning

Range partitioning maps data to partitions based on ranges of values of the partitioning key that have been specified for each partition.

very large database (VLDB)

A very large database is a database that contains a very large number of rows, or occupies an extremely large physical storage space.