經常使用DB2命令

• Table
  

  db2look -d <database> -e -t <schema>.<table_name> -o tmp.sql
  db2 describe table SYSIBMADM.ENV_INST_INFO 
  Altter column size
  ALTER TABLE ${schema}.${table} ALTER COLUMN ${column} SET DATA TYPE VARCHAR(128);

  Merge(http://publib.boulder.ibm.com/infocenter/db2luw/v9/topic/com.ibm.db2.udb.admin.doc/doc/r0010873.htm)
  MERGE INTO employee_file AS e
    USING (SELECT empid, phone, office
           FROM (SELECT empid, phone, office,
                 ROW_NUMBER() OVER (PARTITION BY empid
                 ORDER BY transaction_time DESC) rn
                 FROM transaction_log) AS nt
                 WHERE rn = 1) AS t
    ON e.empid = t.empid
    WHEN MATCHED THEN
       UPDATE SET
          (phone, office) = 
          (t.phone, t.office)
    WHEN NOT MATCHED THEN
       INSERT
          (empid, phone, office)
          VALUES (t.empid, t.phone, t.office)
  
  查看錶佔用的磁盤空間(pages * page_per_size)
  select char(date(t.stats_time))||' '||char(time(t.stats_time)) as statstime
  ,trim(t.tabschema)||'.'||t.tabname as tabname
  , card as rows_per_table
  , t.TBSPACE as "TABLESPACE"
  , decimal(float(t.npages) * b.pagesize / 1024 / 1024,9,2) as used_mb
  , decimal(float(t.fpages) * b.pagesize / 1024 / 1024,9,2) as allocated_mb
  from syscat.tables t, syscat.tablespaces b
  where t.tbspace=b.tbspace 
  and t.tbspace not in ('SYSCATSPACE')
  order by t.TBSPACE,used_mb desc
  with ur;
  
  SELECT rtrim(substr(i.TABSCHEMA,1,8))||'.'||rtrim(substr( i.TABNAME, 1,24)) as TABLE_NAME
  ,b.TBSPACE AS TABLE_SPACE
  , decimal((sum(i.NLEAF) * b.PAGESIZE / 1024 / 1024),12,2) as INDX_USED_PERTABLE
  FROM SYSCAT.INDEXES i, SYSCAT.TABLESPACES b
  WHERE i.TABSCHEMA IS NOT NULL
  AND i.tbspaceid=b.TBSPACEID
  GROUP BY i.TABNAME,i.TABSCHEMA, b.TBSPACE, b.PAGESIZE
  ORDER BY TABLE_SPACE, INDX_USED_PERTABLE DESC WITH UR;
  
  SELECT
  decimal((i.NLEAF * b.PAGESIZE / 1024 / 1024),12,2) as INDX_USED_MB
  FROM SYSCAT.INDEXES i, SYSCAT.TABLESPACES b
  WHERE i.TABSCHEMA IS NOT NULL
  AND i.tbspaceid=b.TBSPACEID
  and i.INDNAME = '${index_name}'
   WITH UR;
  
  
• Processes(applications)
  

  SELECT * FROM SYSIBMADM.APPLICATIONS with ur;

• Check dead lock
  
  SELECT lockwaits.lock_wait_start_time,
              SUBSTR (locker.auth_id, 1, 10) AS locker_auth_id,
              SUBSTR (locker.appl_name, 1, 20) AS locker_appl_name,
              SUBSTR (locked.auth_id, 1, 10) AS locked_auth_id,
              SUBSTR (locked.appl_name, 1, 20) AS locked_appl_name
  FROM    TABLE (SNAPSHOT_LOCKWAIT ('',  - 1)) AS lockwaits,
               TABLE (SNAPSHOT_APPL_INFO ('', - 1)) AS locker,
               TABLE (SNAPSHOT_APPL_INFO ('', - 1)) AS locked
  WHERE   lockwaits.agent_id = locker.agent_id AND
                lockwaits.agent_id_holding_lk = locked.agent_id
  WITH UR;
• 
  

• Sequence
  values previous value for $schema.$seq_name
  values next value for $schema.$seq_name
  
  SELECT   LASTASSIGNEDVAL 
  FROM     sysibm.SYSSEQUENCES 
  WHERE   seqname = '$seq_name' and seqschema = '$schema'  
  WITH UR;
  
  db2 "ALTER SEQUENCE $schema.$seq_name RESTART WITH $seq_num"
  db2ts restart sequence -dbname $database -schema $schema -value $seq_num -name $sequence -mailto $mail_addr
  

• Instance
  

  SELECT * FROM SYSIBMADM.ENV_INST_INFO with ur;

• Load Query
  db2 load query table ${schema.name} [ to ${log_file_path} ]
  
  
• Terminate table loading pending status(will purge all existing data)
  load from /dev/null of del terminate into ${schema.name}
  
  
• db2 get db cfg (check db2 configure parameters)
  
• db2 list command options
  
• Check table status
  

  SELECT t.status, t.access_mode, t.TBSPACEID, t.TBSPACE, t.INDEX_TBSPACE, t.*                FROM syscat.tables t                                                                         WHERE tabschema='${table_schema}' AND tabname = '${table_name}' WITH UR

  SELECT 'set integrity for '||tabschema||'.'||tabname||' immediate checked ;'                FROM syscat.tables                                                                           WHERE tabschema='${table_schema}' and not (status='N' and access_mode='F');

  select t.status, t.access_mode FROM syscat.tables t WHERE t.TABNAME = ${table_name} with ur
  
  
•  Frequetly used Date format 
  http://pic.dhe.ibm.com/infocenter/db2luw/v9r7/index.jsp?topic=%2Fcom.ibm.db2.luw.sql.ref.doc%2Fdoc%2Fr0007107.html
  

  SELECT VARCHAR_FORMAT(TIMESTAMP_ISO(current date - 1 days ), 'YYYY-MM-DD') || ' 00:00:00' FROM SYSIBMADM.ENV_INST_INFO
  
  SELECT VARCHAR_FORMAT(TIMESTAMP_ISO(current timestamp - 2 days ), 'YYYY-MM-DD') || ' 00:00:00' FROM SYSIBMADM.ENV_INST_INFO
  
  values current timestamp
  
  select date(current timestamp)  FROM SYSIBMADM.ENV_INST_INFO with ur

  
  
• Reorg/Run stats
  below SQL is for check if a table pending for reorg
  select TABSCHEMA, TABNAME, REORG_PENDING from SYSIBMADM.ADMINTABINFO a where a.REORG_PENDING = 'Y' and a.TABSCHEMA = ${schema_name} and a.TABNAME = ${table_name} with ur
  
  (http://publib.boulder.ibm.com/infocenter/db2luw/v8/index.jsp?topic=/com.ibm.db2.udb.doc/core/r0001971.htm)
  db2 reorgchk update statistics on table system 
  db2 -v reorgchk on table ${schema_name}.${table_name}
  db2ts reorg table -dbname ${database} -schema ${schema_name} -name ${table_name} -mailto ${mail_group} -dictionary reset -force
  
  run statistics and rebind package(especially for stored procedure) 
  

  module load ibmdb2/db2ts
  db2ts update table statistics -dbname ${database} -schema ${table_sckema} -name ${table_name} -mailto ${mail_group}

• Check Re-org table status
  
  select *
  from sysibmadm.snaptab_reorg r
  where r.TABNAME = ${table_name}
  order by r.REORG_START desc     
  with ur

• Stored Procedure
  query stored procedure and its related infor(like package, view and table etc.)
  select r.* from syscat.ROUTINES r where r.ROUTINENAME = ${table_name} with ur 
  select d.*  from syscat.routinedep d where d.routinename = ${table_name} and d.btype='K'  with ur
  Note:d.btype='K'  stand for package

• DB2 SQL應用調優——解釋工具db2expln的使用及實例分析
  db2expln -database sample -t -g -f "sql query
  db2expln -d ${database} -f imrs_fx.sql -g -t -z @ > imrs_fx.out
  run_db2exfmt -d ${database} -f ${sql file}
  

• db2數據庫的啓動和關閉

  http://space.itpub.net/785478/viewspace-571147
  

db2 list database directory

db2 list node directory

Get snapshot
attach to ${database}

get snapshot for application agentid 24568

module load ibmdb2/client/9.5.7

db2 attach to ${database_name}  Note : Not alias

db2 get snapshot for application agentid 24568

stored procedure pre-compile options
http://publib.boulder.ibm.com/infocenter/db2luw/v9r5/index.jsp?topic=%2Fcom.ibm.db2.luw.apdv.routines.doc%2Fdoc%2Ft0006584.html
http://pic.dhe.ibm.com/infocenter/db2luw/v9r8/index.jsp?topic=%2Fcom.ibm.db2.luw.admin.perf.doc%2Fdoc%2Fc0055082.html

db2 "CALL SET_ROUTINE_OPTS(GET_ROUTINE_OPTS() || ' ISOLATION UR')"
db2 -td@ -vf maxamount.db2

保存修改
Get Dynamic SQL

SELECT * FROM SYSIBMADM.SNAPDYN_SQL x where x.STMT_TEXT like '%CASH_BLOCK_TRADE_DETAIL%';