Queries to view Alert Log content And Alert Location

Quering alert log using SQL query

Oracle 11g开始，提供了X$DBGALERTEXT，可以用来使用sql访问数据库alert日志，在不方便直接访问服务器时，提供了另外的方式访问数据库alert日志。X$DBGALERTEXT的定义如下：

SYS> desc X$DBGALERTEXT
 Name                                            Null?    Type
 ----------------------------------------------------------------------------------- -------- --------------------------------------------------------
 ADDR                                                 RAW(8)
 INDX                                                 NUMBER
 INST_ID                                              NUMBER
 ORIGINATING_TIMESTAMP                                        TIMESTAMP(3) WITH TIME ZONE
 NORMALIZED_TIMESTAMP                                         TIMESTAMP(3) WITH TIME ZONE
 ORGANIZATION_ID                                          VARCHAR2(64)
 COMPONENT_ID                                             VARCHAR2(64)
 HOST_ID                                              VARCHAR2(64)
 HOST_ADDRESS                                             VARCHAR2(46)
 MESSAGE_TYPE                                             NUMBER
 MESSAGE_LEVEL                                            NUMBER
 MESSAGE_ID                                           VARCHAR2(64)
 MESSAGE_GROUP                                            VARCHAR2(64)
 CLIENT_ID                                            VARCHAR2(64)
 MODULE_ID                                            VARCHAR2(64)
 PROCESS_ID                                           VARCHAR2(32)
 THREAD_ID                                            VARCHAR2(64)
 USER_ID                                              VARCHAR2(64)
 INSTANCE_ID                                              VARCHAR2(64)
 DETAILED_LOCATION                                        VARCHAR2(160)
 PROBLEM_KEY                                              VARCHAR2(64)
 UPSTREAM_COMP_ID                                         VARCHAR2(100)
 DOWNSTREAM_COMP_ID                                       VARCHAR2(100)
 EXECUTION_CONTEXT_ID                                         VARCHAR2(100)
 EXECUTION_CONTEXT_SEQUENCE                                   NUMBER
 ERROR_INSTANCE_ID                                        NUMBER
 ERROR_INSTANCE_SEQUENCE                                      NUMBER
 VERSION                                              NUMBER
 MESSAGE_TEXT                                             VARCHAR2(2048)
 MESSAGE_ARGUMENTS                                        VARCHAR2(128)
 SUPPLEMENTAL_ATTRIBUTES                                      VARCHAR2(128)
 SUPPLEMENTAL_DETAILS                                         VARCHAR2(128)
 PARTITION                                            NUMBER
 RECORD_ID                                            NUMBER

比较常用的SQL如下(可以得到类似直接访问文本格式alert日志样式的结果)：

SQL> select ORIGINATING_TIMESTAMP, MESSAGE_TEXT from X$DBGALERTEXT;

Finding Trace File Path using SQL

11g开始，Oracle提供了X$DBGDIREXT接口，可以用来查看diagnostic_dest下的目录和文件。X$DBGDIREXT的定义如下：

 SYS> desc X$DBGDIREXT;
 Name                                            Null?    Type
 ----------------------------------------------------------------------------------- -------- --------------------------------------------------------
 ADDR                                                 RAW(8)
 INDX                                                 NUMBER
 INST_ID                                              NUMBER
 PHYSICAL_PATH                                            VARCHAR2(444)
 LOGICAL_PATH                                             VARCHAR2(444)
 PHYSICAL_FILE                                            VARCHAR2(68)
 LOGICAL_FILE                                             VARCHAR2(68)
 CREATION_TIME                                            TIMESTAMP(3) WITH TIME ZONE
 MODIFY_TIME                                              TIMESTAMP(3) WITH TIME ZONE
 LVL                                                  NUMBER
 TYPE                                                 NUMBER

一个非常handy的用法：有时候不熟悉Oracle的人，我们需要它帮忙把alert日志取出来的时候，由于11g的alert是放在diagnostic中的，描述日志的路径每次都要费很大的劲，现在我们可以用下面sql来直接获取到alert日志的路径了：

SELECT PHYSICAL_PATH || CHR(47) || PHYSICAL_FILE
  FROM X$DBGDIREXT
 WHERE 1 = 1
   AND PHYSICAL_FILE LIKE 'alert_%'
   AND PHYSICAL_PATH LIKE '%rdbms%'
/