v$SESSION是我们常用的动态性能视图之一，其SQL_ID字段常用来检测会话当前执行的SQL语句，但在少数版本中V$SESSION的SQL_ID列可能不正常地显示SQL_ID，一般是在Session Active或执行Pl/SQL的时候SQL_ID为NULL,以下是部分相关的部分BUG列表：  

BUG#	Affected Version	Symptom	Fix Version
Bug 13068790 - the value of v$session.sql_id of active session is null [ID 13068790.8]	11.2.0.2.4 Patch Set Update 11.2.0.2.3 Patch Set Update 11.2.0.2.1 Patch Set Update 11.2.0.2 11.2.0.1	active session's sql_id, sql_address may be null or 0 out while a recursive call is executing.	11.2.0.3 (Server Patch Set)
Bug 14393463 : IN V$SESSION, SQL_ID IS NOT NULL BUT STATUS IS INACTIVE	11.2.0.3	Abstract: IN V$SESSION, SQL_ID IS NOT NULL BUT STATUS IS INACTIVE	No Workaround Now
Bug 11670241 : NULL V$SESSION.SQL_ID WHEN RUNNING SLOW SQL IN PL/SQL	11.2.0.1	In 11.2 (maybe also in 10g), when running a slow sql in pl/sql, we found that v$session.sql_id will be null.  This is very inconvenient for troubleshooting, because we cannot tell what sql is running by a session. The only workaround seems to turn on sql_trace.	No Workaround Now
Bug 13089859 : THE VALUE OF V$SESSION.SQL_ID OF ACTIVE SESSION IS NULL	11.2.0.2	In some cases customer needs to find out SQL statements which are executed in active sessions and tune them. So they needs the values of SQL_ID in v$session.But that column occasionally have NULL values and then it make a difficulty in tuning problematic SQL statements. The following columns of v$session have NULL or zero (0) values even though the session status is ACTIVE: SQL_ID, SQL_ADDRESS, SQL_HASH_VALUE, SQL_EXEC_START, SQL_EXEC_ID.	12.1

  另附V$SESSION视图相关的BUG列表：  

NB	Bug	Fixed	Description
	13545355	12.1.0.0	V$SESSION.FIXED_TABLE_SEQUENCE may show negative values if DB up for a long time
	10299006	11.2.0.2.GIPSU03, 11.2.0.3, 12.1.0.0	Excess oraagent.bin sessions in the database (in V$SESSION) / ORA-20
	9339310	11.2.0.2, 12.1.0.0	V$SESSION may not show correct SQL_ID
P	7214679	11.2.0.2, 12.1.0.0	OSUSER in V$SESSION is missing extended characters
	13068790	11.2.0.3	the value of v$session.sql_id of active session is null
	8655331	11.2.0.2	V$SESSION.COMMAND has wrong code for commands >= 128
	6994490	10.2.0.5, 11.2.0.1	Multibyte characters garbled in V$SESSION client information
	6993310	11.2.0.1	V$SESSION.CLIENT_INFO cannot be set to NULL with fix for bug 5915741
	6661393	10.2.0.5, 11.1.0.7, 11.2.0.1	Setting CLIENT_INFO does not affect CLIENT_IDENTIFIER
	8674660	10.2.0.5, 11.1.0.7	DIAG process gets PGA memory corruption or ORA-600[kjzhablar:idx] or dump in RAC env
	5928612	10.2.0.4, 11.1.0.7	V$SESSION SQL_ADDRESS / SQL_HASH_VALUE not set for DBMS_JOBs
	5915741	10.2.0.5, 11.1.0.6	ORA-29275 selecting from V$SESSION with multibyte DB
	5246867	10.2.0.3, 11.1.0.6	V$SESSION.PROGRAM is not populated properly for JDBC Thin
	5140631	10.2.0.4, 11.1.0.6	V$SESSION.sql_address not set by DBMS_SCHEDULER
	5078627	10.2.0.4, 11.1.0.6	Audit sessionid is zero for jobs invoked by job scheduler
	5010879	10.2.0.4, 11.1.0.6	V$SESSION slow and does not show any BLOCKING_SESSION column data
	4507211	10.2.0.3, 11.1.0.6	Thin JDBC connection properties terminal not reflected in V$SESSION
	4496189	9.2.0.8, 10.2.0.2, 11.1.0.6	V$SESSION.PROGRAM can contain partial MULTIBYTE characters
	4493741	10.2.0.4, 11.1.0.6	Cannot see SQL_TEXT for procedure calls from EXECUTE IMMEDIATE
	4383610	10.1.0.5, 10.2.0.2, 11.1.0.6	application info attributes are not translated correctly in utf16 environment
	3735857	10.2.0.2, 11.1.0.6	V$SESSION.OSUSER not populated for JDBC clients
	9322219	10.2.0.5.5	Session dump with stack memcpy <- kjzhgigblk in RAC env
	5884519	10.2.0.4	V$SESSION is slow with fix for bug 5010879
	5481650	10.2.0.4	GV$SESSION.blocking_session has incorrect value
	4393134	10.2.0.1	OracleConnectionCachImpl does not set connection properties (eg V$SESSION.PROGRAM)
	3258390	9.2.0.6, 10.1.0.4, 10.2.0.1	V$SESSION.SCHEMANAME may return wrong value in PLSQL of another user
	2740805	9.2.0.5, 10.1.0.2	V$SESSION.OS_USER set incorrectly if client uses RADIUS
P	2661173	9.2.0.4, 10.1.0.2	Linux: V$SESSION.PROGRAM shows full path instead of executable name
P	2628258	9.2.0.3, 10.1.0.2	Win: Trailing "\0" added to MACHINE column of V$SESSION
	2123156	9.0.1.4, 9.2.0.2, 10.1.0.2	FAILOVER: V$SESSION.FAILOVER_METHOD / FAILOVER _TYPE may be wrong for second connection
	2106360	9.2.0.2, 10.1.0.2	MODULE (V$SESSION/V$SQL) should default to the PROGRAM name
P	2026123	8.1.7.3, 9.0.1.4, 9.2.0.1	V$SESSION.PROGRAM displays '?' for OCI clients
	1326191	9.2.0.1	V$SESSION.OSUSER is always 'ORACLE' using JDBC Thin
	1249631	8.1.7.3, 9.0.1.3, 9.2.0.1	V$SESSION.SQL_ADDRESS is not cleared when a cursor is unmapped
	1540012	9.0.1.0	V$SESSION and V$SESSTAT "IDLE TIME" may not increment
	1500535	8.1.7.1.B, 9.0.1.0	V$SESSION.PROCESS not set by the THIN driver
	1290469	8.1.6.3.J, 8.1.7.0	V$SESSION does not show useful information for JDBC thin clients
	1237128	8.1.7.0	V$SESSION.PROGRAM may not contain a value
	889678	8.1.7.0	V$SESSION had short sizes for TERMINAL and MACHINE fields
P	759086	7.3.4.4	SP2: Program column in V$SESSION shows up as ? (broken fix)