..FROM tableY in parallel for nonpartitioned and partitioned tables.
Oracle uses a set of PE processes executing block-range parallelism for the SELECT
portion of the INSERT statement. These PE processes pass the rows to a second set
of PE processes, which insert the rows into the target table. The target table can be a
nonpartitioned or partitioned table. Parallelism for an insert is not exactly blockrange
or partition-based.
176 | Chapter 7: Oracle Performance
Oracle and Memory Resources
Accessing information in memory is much faster than accessing information on a
disk. An Oracle instance uses the database server??™s memory resources to cache the
information accessed to improve performance. Oracle utilizes an area of shared
memory called the System Global Area (SGA) and a private memory area for each
server process called the Program Global Area (PGA).
Prior to Oracle9i, youcou ld only specify the size for the SGA or any of its components
??”database buffer cache, shared pool, or large pool??”in the initialization file,
and the size of these memory allocations could not be changed without shutting
down and restarting the instance.
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