oracle常用

主要事理於2011、2013年，Oracle11g

1、設置變量

     set timing on
     alter session enable parallel dml;
     alter session enable parallel query;
     alter session enable parallel ddl;
     alter session set workarea_size_policy=manual ;
     alter session set sort_area_size=209715200 ;
     alter session set sort_area_retained_size=209715200 ;
     alter session set hash_area_size=209715200;
     alter session set db_file_multiblock_read_count=64;
     alter session set optimizer_mode=all_rows;
     --alter session set events '6550 trace name ERRORSTACK level 3';
     --alter session set events '10035 trace name context forever, level 3';
     set arraysize 1000 head off termout off
     exec admin_set_module('DAY_HANGAME','CRON');
     exec SP_DW_DAY_HANGAME(to_char(sysdate-1,'mmdd'));
     spool off
     exit

2、Data Warehouse Best Practices for Oracle Database 11g ：
Tips for a balanced system
Total throughput = # cores X 200MB
Use 1 HBA port per CPU
Use 1 disk controller per HBA Port
Max of 10 physical disks per controller
Use more smaller drives (146GB or 300 GB
Use minimum of 4GB of Memory per core
Use RAID 1 with ASM
Interconnect bandwidth = IO subsystem bandwidth

Tips for the Staging Layer
Use external tables
Load using parallel DML stmts CTAS or IAS
Use data compression
Considering range partitioning fact table to enable partition exchange loads

Tips for the Foundation Layer
Partition fact tables to get partition pruning
Sub-partitions by hash to achieve partition wise joins
Use parallel execution to allow multiple process to work on large queries
Number of sub-partitions needs to be a power of 2 and should be greater than or equal to the DOP

Tips for the Access Layer
Partition fact tables to get partition pruning
Create bitmap indexes on all FK columns
Set STAR_TRANSFORMATION_ENABLED to true

Tips for System Management
Use Parallel Execution where appropriate
Take hourly AWR or statspack report
Use EM to do real-time system monitoring
Use Resource Manager to ensure necessary users get high priority on the system
Always have accurate Optimizer statistics
Use INCREMENTAL statistic maintenance or copy_stats to keep large partitioned fact table up to date in a timely manner
Set only the initialization parameters that you need to
3、oracle startup
1. Start an instance.
When Oracle starts an instance, it reads the server parameter file (SPFILE) or
initialization parameter file to determine the values of initialization parameters. Then,
it allocates an SGA, which is a shared area of memory used for database information,
and creates background processes.
2. Mount the database.
To mount the database, the instance finds the database control files and opens them. Control files
are specified in the CONTROL_FILES initialization parameter in the parameter file
used to start the instance. Oracle then reads the control files to get the names of the
database’s datafiles and redo log files
3. Open the database.
When you open the database, Oracle opens the online datafiles and redo log files. If a
tablespace was offline when the database was previously shut down, the tablespace
and its corresponding datafiles will still be offline when you reopen the database.

4、查oracle鎖：

     SELECT A.OWNER,
A.OBJECT_NAME,
B.XIDUSN,
B.XIDSLOT,
B.XIDSQN,
B.SESSION_ID,
B.ORACLE_USERNAME,
B.OS_USER_NAME,
B.PROCESS,
B.LOCKED_MODE,
C.MACHINE,
C.STATUS,
C.SERVER,
C.SID,
C.SERIAL#,
C.PROGRAM
FROM ALL_OBJECTS A,
V$LOCKED_OBJECT B,
SYS.GV_$SESSION C
WHERE ( A.OBJECT_ID = B.OBJECT_ID )
AND (B.PROCESS = C.PROCESS )
ORDER BY 1, 2;

      alter system kill session 'sid, serial#'; --殺掉

5、更改時間格式

    alter session set nls_date_format= 'yyyy-mm-dd hh24:mi:ss';

6、去重

    select mp_type, orig_mp_type, class_id, plat_type
     from(select mp_type, orig_mp_type, class_id, plat_type, row_number() over (partition by orig_mp_type,class_id,plat_type order by mp_type desc)                                                                  rn from p_media_prod_map
     ) a where rn = 1;
delete from ts_action_software_def
where rowid not in (select rd
                       from (select rowid rd,
                                    row_number() over(partition by software_name order by id desc) rn
                               from ts_action_software_def)
                      where rn = 1);

7、導入導出

exp rdd/rdd file=/tmp/rdd.dmp owner=rdd
imp rdd/rdd fromuser=rdd touser=rdd file=/tmp/rdd.dmp

8、輸出字符集

export NLS_LANG=AMERICAN_AMERICA.UTF8 #linux
set NLS_LANG=AMERICAN_AMERICA.ZHS16GBK #windows

9、查表

select tab.table_name, comm.COMMENTS, tab.OWNER from all_tab_comments comm, all_tables tab where comm.table_name = tab.TABLE_NAME and comm.OWNER = tab.OWNER and tab.OWNER in {0} and tab.table_name in('FIN_ACCOUNTINFO') order by tab.OWNER, tab.TABLE_NAME

10、查列

select md.COLUMN_NAME,
       md.COMMENTS,
       md.data_type,
       case
         when cons.COLUMN_NAME is not null then
          'Y'
       end as column_key,
       md.nullable
    from (SELECT T.COLUMN_NAME,
               T1.COMMENTS,
               case
                 when t.DATA_PRECISION is not null then
                  T.DATA_TYPE || '(' || T.DATA_LENGTH || ',' ||
                  t.DATA_PRECISION || ')'
                 when t.DATA_LENGTH is not null then
                  T.DATA_TYPE || '(' || T.DATA_LENGTH || ')'
                 else
                  T.DATA_TYPE
               end as data_type,
               t.nullable,
               t.COLUMN_ID,
               t.TABLE_NAME,
               t.OWNER
          FROM ALL_TAB_COLUMNS T, ALL_COL_COMMENTS T1
         WHERE T.TABLE_NAME = T1.TABLE_NAME
           AND T.COLUMN_NAME = T1.COLUMN_NAME
           AND T.OWNER = T1.OWNER
           AND T.OWNER = '{0}'
           AND T.TABLE_NAME = '{1}') md
    left join all_cons_columns cons
    on md.owner = cons.OWNER
    and md.table_name = cons.TABLE_NAME
    and md.column_name = cons.COLUMN_NAME
    and cons.constraint_name like 'PK%'
    order by md.COLUMN_ID

11、最新查詢語句

  select * from v$sqlarea t where t.SQL_TEXT like '%KPI_LEV2%' 
order by t.LAST_ACTIVE_TIME desc 

12、表空間
–查詢表空間使用情況

 SELECT UPPER(F.TABLESPACE_NAME) "表空間名",
  D.TOT_GROOTTE_MB "表空間大小(M)",
  D.TOT_GROOTTE_MB - F.TOTAL_BYTES "已使用空間(M)",
  TO_CHAR(ROUND((D.TOT_GROOTTE_MB - F.TOTAL_BYTES) / D.TOT_GROOTTE_MB * 100,2),'990.99') || '%' "使用比",
  F.TOTAL_BYTES "空閒空間(M)",
  F.MAX_BYTES "最大塊(M)"
  FROM (SELECT TABLESPACE_NAME,
  ROUND(SUM(BYTES) / (1024 * 1024), 2) TOTAL_BYTES,
  ROUND(MAX(BYTES) / (1024 * 1024), 2) MAX_BYTES
  FROM SYS.DBA_FREE_SPACE
  GROUP BY TABLESPACE_NAME) F,
  (SELECT DD.TABLESPACE_NAME,
   ROUND(SUM(DD.BYTES) / (1024 * 1024), 2) TOT_GROOTTE_MB
  FROM SYS.DBA_DATA_FILES DD
  GROUP BY DD.TABLESPACE_NAME) D
  WHERE D.TABLESPACE_NAME = F.TABLESPACE_NAME
  ORDER BY 1

–查詢表空間的free space

select tablespace_name,
  count(*) as extends,
  round(sum(bytes) / 1024 / 1024, 2) as MB,
  sum(blocks) as blocks
  from dba_free_space
  group by tablespace_name

–查詢表空間的總容量

  select tablespace_name, sum(bytes) / 1024 / 1024 as MB
  from dba_data_files
  group by tablespace_name;

–查詢表空間使用率

 select total.tablespace_name,
  round(total.MB, 2) as Total_MB,
  round(total.MB - free.MB, 2) as Used_MB,
  round((1 - free.MB / total.MB) * 100, 2) || '%' as Used_Pct
  from (select tablespace_name, sum(bytes) / 1024 / 1024 as MB
  from dba_free_space
  group by tablespace_name) free,
  (select tablespace_name, sum(bytes) / 1024 / 1024 as MB
  from dba_data_files
  group by tablespace_name) total
  where free.tablespace_name = total.tablespace_name; 

13、列字符串連接

select province_id, WMSYS.WM_CONCAT(area_id) from area_info group by province_id