例：查询约束信息 SQL SELECT * FROM user_constraints; SQL SELECT * FROM user_cons_columns; 例：查询表空间块的大小 SQLSELECT tablespace_name,block_size segment_type FROM dba_segments; 例：查询当前段的类型 SQLSELECT distinct segment_type FROM dba_segments; 例：查询scott的emp表的段信息 SQLSELECT * FROM dba_segments 2WHERE owner=SCOTT and segment_name=EMP; 例：查询scott的emp表的区信息 SQLSELECT * FROM dba_extents 2WHERE owner=SCOTT and segment_name=EMP;例：查询设置shared pool 参数 SQLSHOW PARAMETER shared_pool_size SQLSELECT * FROM v$parameter WHERE parameter=shared_pool_size; 例：查询当前shared pool大小 SQLSELECT * FROM v$sgastat WHERE pool=shared pool;例：查询设置db buffer cache参数 SQLSHOW PARAMETER cache_size SQLSELECT * FROM v$parameter WHERE parameter like %cache_size%; 例：查询当前db buffer cachel大小 SQLSELECT * FROM v$sgastat WHERE name=buffer cache; SQLSELECT * FROM v$buffer_pool; 例：查询设置db buffer cache参数 SQLSHOW PARAMETER log_buffer SQLSELECT * FROM v$parameter WHERE parameter=log_buffer; 例：查询当前log buffer大小 SQLSELECT * FROM v$sgastat WHERE name=log buffer;