复制粘贴下面的语句没有任何意义，该如何学习呢？
1、分析这个语句，看别人是怎么思考的、怎么想的
2、对照着这个语句，写一些别的语句，例如：直接路径写等
分析多了，自己也就会写了。
SELECT a.event,
a.sid,
c.sql_hash_value hash_vale,
decode(d.ktssosegt,
1,
'SORT',
2,
'HASH',
3,
'DATA',
4,
'INDEX',
5,
'LOB_DATA',
6,
'LOB_INDEX',
NULL) AS segment_type,
b.tablespace_name,
b.file_name
FROM v$session_wait a, DBA_data_files b, v$session c, x$ktsso d
WHERE c.saddr = d.ktssoses(+)
AND c.serial# = d.ktssosno(+)
AND d.inst_id(+) = userenv('instance')
AND a.sid = c.sid
AND a.p1 = b.file_id
AND a.event = 'direct path read'
UNION ALL
SELECT a.event,
a.sid,
d.sql_hash_value hash_value,
decode(e.ktssosegt,
1,
'SORT',
2,
'HASH',
3,
'DATA',
4,
'INDEX',
5,
'LOB_DATA',
6,
'LOB_INDEX',
NULL) AS segment_type,
b.tablespace_name,
b.file_name
FROM v$session_wait a,
dba_temp_files b,
v$parameter c,
v$session d,
x$ktsso e
WHERE d.saddr = e.ktssoses(+)
AND d.serial# = e.ktssosno(+)
AND e.inst_id(+) = userenv('instance')
AND a.sid = d.sid
AND b.file_id = a.p1 - c.VALUE
AND c.NAME = 'db_files'
AND a.event = 'direct path read'
/

复制粘贴下面的语句没有任何意义，该如何学习呢？
1、分析这个语句，看别人是怎么思考的、怎么想的
2、对照着这个语句，写一些别的语句，例如：直接路径写等
分析多了，自己也就会写了。
SELECT a.event,
a.sid,
c.sql_hash_value hash_vale,
decode(d.ktssosegt,
1,
'SORT',
2,
'HASH',
3,
'DATA',
4,
'INDEX',
5,
'LOB_DATA',
6,
'LOB_INDEX',
NULL) AS segment_type,
b.tablespace_name,
b.file_name
FROM v$session_wait a, DBA_data_files b, v$session c, x$ktsso d
WHERE c.saddr = d.ktssoses(+)
AND c.serial# = d.ktssosno(+)
AND d.inst_id(+) = userenv('instance')
AND a.sid = c.sid
AND a.p1 = b.file_id
AND a.event = 'direct path read'
UNION ALL
SELECT a.event,
a.sid,
d.sql_hash_value hash_value,
decode(e.ktssosegt,
1,
'SORT',
2,
'HASH',
3,
'DATA',
4,
'INDEX',
5,
'LOB_DATA',
6,
'LOB_INDEX',
NULL) AS segment_type,
b.tablespace_name,
b.file_name
FROM v$session_wait a,
dba_temp_files b,
v$parameter c,
v$session d,
x$ktsso e
WHERE d.saddr = e.ktssoses(+)
AND d.serial# = e.ktssosno(+)
AND e.inst_id(+) = userenv('instance')
AND a.sid = d.sid
AND b.file_id = a.p1 - c.VALUE
AND c.NAME = 'db_files'
AND a.event = 'direct path read'
/