
11.3
Affecting Query Rewrite Performance 331
Chapter 11
hash partitions [1]. Partition query rewrite is known as PCT
query rewrite. A materialized view can include a partition marker
as a replacement for a partition key. The partition marker allows
specific identification of specific partitions, allowing query rewrite
on those marked partitions as pruned partitions. A partition
marker can identify one or more individual partitions. Once
again, all rows in a marked partition must be accessed for parti-
tioned query rewrite to occur. Also, only wholly fresh partitions
can be used for query rewrite. Only fresh partitions have an avail-
able partition marker ...