关于index full scan 和index fast full scan

TO_TO_RO

Mr.huang is right

outdo

FULL 类似全表扫描，不管分支还是叶节点一块读入。
FAST FULL 是按照叶节点进行顺序读。

Yong Huang

outdo 发表于 2012-1-5 23:18
FULL 类似全表扫描，不管分支还是叶节点一块读入。
FAST FULL 是按照叶节点进行顺序读。

You got it backward.

Yong Huang

outdo

Yong Huang 发表于 2012-1-6 23:09
You got it backward.

Yong Huang

哦？11G里已经不是这样的了？

Yong Huang

> 哦？11G里已经不是这样的了？

This is from the 11.2 documentation:
http://docs.oracle.com/cd/E11882 ... /ex_plan.htm#i23461

"INDEX FULL SCAN
Retrieval of all rowids from an index when there is no start or stop key. Indexed values are scanned in ascending order."

"INDEX FAST FULL SCAN
Retrieval of all rowids (and column values) using multiblock reads. No sorting order can be defined. Compares to a full table scan on only the indexed columns. Only available with the cost based optimizer."

Yong Huang

sundog315

outdo 发表于 2012-1-6 13:18
FULL 类似全表扫描，不管分支还是叶节点一块读入。
FAST FULL 是按照叶节点进行顺序读。

反了吧？