WorkingScripts » DB2

Task Manager, System Monitor – best thing for DB2

Iouri Chadour — Fri, 22 May 2009 11:51:24 +0000

One of my colleagues have introduced me to this utility and we had our DBAs install it on the system, and voila – you can see DB2 in works: it’s running snapshots online, you can see bufferpools usage, your top processes and much much more. Here is a link to a IBM page that has a detailed description, screenshots:

http://www.ibm.com/developerworks/data/library/techarticle/dm-0812wang/

DB2 Escape characters in queries

Iouri Chadour — Wed, 18 Feb 2009 05:05:00 +0000

Recently I had to use escape characters in DB2 queries and after looking through documentation here is a simple way to do this. You can define you escape character using

{escape '\'}

right after the statement your are trying to use it, here is a sample statement:

select oprid, oprdefndesc

from psoprdefn

where oprid like '%\_%' {escape '\'}

Deleting a lot of rows fast

Iouri Chadour — Wed, 19 Mar 2008 21:36:00 +0000

Need to delete millions of rows from a table fast? Here is how you can do this:

ALTER TABLE table_name ACTIVATE NOT LOGGED INITIALLY; --disable logging
DELETE FROM table_name WHERE ....;
COMMIT; --Commits and enable logging

DB2 Space Management

Iouri Chadour — Wed, 12 Mar 2008 21:52:00 +0000

Here are some very useful utility SQLs that will allow you to understand your space usage, system and other useful stuff:

DB2 Space Usage & Status

-- to find tablespace status, type , usage run following SQL
select substr(tablespace_name,1,20) Tablespace_name, 
    case t.TBSPACETYPE 
        when 'S' then 'System Managed'
        when 'D' then 'Database managed'
    end as TBSManaged, 
    (used_pages/total_pages ) * 100 usedPCT, 
    s.total_pages Total_pages, 
    s.used_pages Used_pages, 
    (s.total_pages - s.USABLE_PAGES ) Overhead_pgs, 
    s.NUM_CONTAINERS No_of_containers,
    s.free_pages Free_pages,
    case t.DATATYPE 
        when 'A' then ' ALL typ perm '
        when 'L'  then ' Large '
        when 'T'  then ' System Temp'
        when 'U'  then ' User Temp '
    end as TBStype, 
    case s.TABLESPACE_STATE 
        when 0 then ' Normal ' 
        when 1 then ' Quiesced: SHARE ' 
        when 2 then ' Quiesced: UPDATE ' 
        when 4 then ' Quiesced: EXCLUSIVE ' 
        when 8 then ' Load pending ' 
        when 16 then ' Delete pending ' 
        when 32 then ' Backup pending ' 
        when 64 then ' Roll forward in progress ' 
        when 128 then ' Roll forward pending ' 
        when 256 then ' Restore pending ' 
        when 512 then ' Disable pending ' 
        when 1024 then ' Reorg in progress ' 
        when 2048 then ' Backup in progress ' 
        when 4096 then ' Storage must be defined ' 
        when 8192 then ' Restore in progress ' 
        when 16384 then ' Offline and not accessible ' 
        when 32768 then ' Drop pending ' 
        when 33554432 then ' Storage may be defined ' 
        when 67108864 then ' Storage Definition is in (final) state ' 
        when 134217728 then ' Storage Definition was changed prior to rollforward ' 
        when 268435456 then ' DMS rebalancer is active ' 
        when 536870912 then ' TBS deletion in progress ' 
        when 1073741824 then ' TBS creation in progress ' end TABLESPACE_STATE 
from table(snapshot_tbs_cfg(' ',-1)) as s, sysibm.systablespaces t where s.tablespace_name = t.tbspace ;

DB2 Unused Space

-- GETTING WASTED SPACE
select TBSPACE, ((80 - usedPCT) *  total_pages/100)*4/1000 SPACE_WASTED
FROM
    ( select substr(tablespace_name,1,20) TBSPACE,
        total_pages,
        used_pages,
        free_pages, 
        (used_pages*100/total_pages )  usedPCT
    from table(snapshot_tbs_cfg(' ',-1)) as tbs ) 
AS TABLE_SPACE
WHERE usedPCT < 60

DB2 Scripts – Table Management

Iouri Chadour — Wed, 05 Mar 2008 01:39:00 +0000

Here are a few more nice DB2 scripts that would save you time:

Get all tables in Table Space

-- Get all tables in particular tablespaceselect SUBSTR(TABNAME,1,25) "TABNAME", SUBSTR(TABSCHEMA,1,15) "SCHEMA", NPAGES, CARD from syscat.tables where tbspace = '?'

Generate Grants for all tables in Table Space

-- Genereating GRANTS SELECT 'grant select on ' || tabname || ' to PSFDEV' || ';'  FROM syscat.tables WHERE tabname NOT IN (SELECT tabname                         FROM syscat.tabauth                        WHERE grantee = 'PSFDEV')   AND tabschema = 'PSFSSYS'   AND (type = 'T' OR type = 'V')