CVM - complex view merging
SPJ - select-project-join
SJC - set join conversion
SU - subquery unnesting
OBYE - order by elimination
ST - star transformation
qb - query block
LB - leaf blocks
DK - distinct keys
LB/K - average number of leaf blocks per key
DB/K - average number of data blocks per key
CLUF - clustering factor
NDV - number of distinct values
Resp - response cost
Card - cardinality
Resc - resource cost
NL - nested loops (join)
SM - sort merge (join)
HA - hash (join)
CPUCSPEED - CPU Speed
IOTFRSPEED - I/O transfer speed
IOSEEKTIM - I/O seek time
SREADTIM - average single block read time
MREADTIM - average multiblock read time
MBRC - average multiblock read count
MAXTHR - maximum I/O system throughput
SLAVETHR - average slave I/O throughput
dmeth - distribution method
1: no partitioning required
2: value partitioned
4: right is random (round-robin)
512: left is random (round-robin)
8: broadcast right and partition left
16: broadcast left and partition right
32: partition left using partitioning of right
64: partition right using partitioning of left
128: use hash partitioning dimension
256: use range partitioning dimension
2048: use list partitioning dimension
1024: run the join in serial
0: invalid distribution method
sel - selectivity
ptn - partition
*******************************************
这一部分解释trace文件中用到的一些缩写指标的含义，这些指标在trace文件中被经常使用，所以trace文件开头他们的具体地含义列出来了，以便更加容易的
阅读trace文件头
下一部分是绑定变量的描述：
*******************************************
Peeked values of the binds in SQL statement
*******************************************
接下来部分是一些修复bug信息，以及和性能相关的初始化参数的值，这一部分的内容较多：
***************************************
PARAMETERS USED BY THE OPTIMIZER
********************************
*************************************
PARAMETERS WITH ALTERED VALUES
******************************
_pga_max_size = 490700 KB
*********************************
Bug Fix Control Environment
***************************
fix 4611850 = enabled
fix 4663804 = enabled
fix 4663698 = enabled
fix 4545833 = enabled
。。。。。。。。。。。。。。。。。
*************************************
PARAMETERS WITH DEFAULT VALUES
******************************
optimizer_mode_hinted = false
optimizer_features_hinted = 0.0.0
parallel_execution_enabled = true
parallel_query_forced_dop = 0
parallel_dml_forced_dop = 0
parallel_ddl_forced_degree = 0
parallel_ddl_forced_instances = 0
_query_rewrite_fudge = 90
optimizer_features_enable = 10.2.0.4
_optimizer_search_limit = 5
cpu_count = 24
active_instance_count = 1
parallel_threads_per_cpu = 2
hash_area_size = 131072
。。。。。。。。。。。
*********************************
Bug Fix Control Environment
***************************
fix 4611850 = enabled
fix 4663804 = enabled
fix 4663698 = enabled
fix 4545833 = enabled
fix 3499674 = disabled
fix 4584065 = enabled
fix 4602374 = enabled
fix 4569940 = enabled
fix 4631959 = enabled
fix 4519340 = enabled
fix 4550003 = enabled
fix 4488689 = enabled
***