PATH in 10053 Trace 的存取路径代码和解释

越来越多的DBA和Developer开始研究CBO相关的10053 Trace.
可以参考老刘(Lewis)的Cost Based Oracle Fundamentals第14章 - The 10053 Trace File.

Oracle 11g之前,PATH 用代码表示,阅读起来极不方便, 因此木匠干脆罗列出来有关表扫描的Access PATH代码含义:

# PATH in 10053 trace
-- table access path


0 parallel hint
1 no access path spec
2 table scan
3 index unique
4 index range
5 index and-equal
6 order by using an index
7 open cluster
8 hash cluster
9 rowid lookup
10 range scan backwards
11 rowid range scan
12 driving_site hint
14 cache hint
15 nocache hint
16 partitions hint
17 nopartitions hint
18 anti-join
19 index rowid range scan
20 bitmap index
21 parallel_index hint
22 noparallel_index hint
23 index fast full scan
24 swap inputs to join
25 fact table
26 not a fact table
27 merge of this view
28 do not push join predicate into this view
29 push join predicate into this view
30 no_merge of this view
31 semi-join