Oracle DBA Checklist

 

Index

I. Daily Procedures *

A. Verify all instances are up *

B. Look for any new alert log entries *

C. Verify DBSNMP is running *

D. Verify success of database backup *

E. Verify success of database archiving to tape *

F. Verify enough resources for acceptable performance *

G. Read DBA manuals for one hour *

II. Weekly Procedures *

A. Look for objects that break rules *

B. Look for security policy violations *

C. Look in SQL*Net logs for errors, issues *

D. Archive all Alert Logs to history *

E. Visit home pages of key vendors *

III. Monthly Procedures *

A. Look for Harmful Growth Rates *

B. Review Tuning Opportunities *

C. Look for I/O Contention *

D. Review Fragmentation *

E. Project Performance into the Future *

F. Perform Tuning and Maintenance *

IV. Appendix *

A. Daily Procedures *

B. Weekly Procedures *

V. References *

 

  1. Daily Procedures
  2.  

    1. Verify all instances are up
    2. Make sure the database is available. Log into each instance and run daily reports or test scripts. Some sites may wish to automate this.

      Optional implementation: use Oracle Enterprise Manager's 'probe' event.

    3. Look for any new alert log entries
    1. Verify DBSNMP is running
      1. Log on to each managed machine to check for the 'dbsnmp' process.

      For Unix: at the command line, type ps –ef | grep dbsnmp. There should be two dbsnmp processes running. If not, restart DBSNMP.

    2. Verify success of database backup
    3. Verify success of database archiving to tape
    4. Verify enough resources for acceptable performance
      1. Verify free space in tablespaces.
      2. For each instance, verify that enough free space exists in each tablespace to handle the day’s expected growth. As of <date>, the minimum free space for <repeat for each tablespace>: [ < tablespace > is < amount > ]. When incoming data is stable, and average daily growth can be calculated, then the minimum free space should be at least <time to order, get, and install more disks> days’ data growth.

        1. Go to each instance, run free.sql to check free mb in tablespaces.
        2. Compare to the minimum free MB for that tablespace. Note any low-space conditions and correct.

        3. Go to each instance, run space.sql to check percentage free in tablespaces.

        Compare to the minimum percent free for that tablespace. Note any low-space conditions and correct.

      3. Verify rollback segment.
      4. Status should be ONLINE, not OFFLINE or FULL, except in some cases you may have a special rollback segment for large batch jobs whose normal status is OFFLINE.

        1. Optional: each database may have a list of rollback segment names and their expected statuses.
        2. For current status of each ONLINE or FULL rollback segment (by ID not by name), query on V$ROLLSTAT.
        3. For storage parameters and names of ALL rollback segment, query on DBA_ROLLBACK_SEGS. That view’s STATUS field is less accurate than V$ROLLSTAT, however, as it lacks the PENDING OFFLINE and FULL statuses, showing these as OFFLINE and ONLINE respectively.
      5. Identify bad growth projections.
      6. Look for segments in the database that are running out of resources (e.g. extents) or growing at an excessive rate. The storage parameters of these segments may need to be adjusted. For example, if any object reached 200 as the number of current extents, upgrade the max_extents to unlimited.

        1. To gather daily sizing information, run daily_01.sql
        2. To check current extents, run nr_extents.sql
        3. Query current table sizing information
        4. Query current index sizing information
        5. Query growth trends
      7. Identify space-bound objects.
      8. Space-bound objects’ next_extents are bigger than the largest extent that the tablespace can offer. Space-bound objects can harm database operation. If we get such object, first need to investigate the situation. Then we can use ALTER TABLESPACE <tablespace> COALESCE. Or add another datafile.

        1. Run spacebound.sql. If all is well, zero rows will be returned.
      9. Processes to review contention for CPU, memory, network or disk resources.
        1. To check CPU utilization, go to x:\web\phase2\default.html =>system metrics=>CPU utilization page. 400 is the maximum CPU utilization because there are 4 CPUs on phxdev and phxprd machine. We need to investigate if CPU utilization keeps above 350 for a while.

       

    5. Read DBA manuals for one hour

Nothing is more valuable in the long run than that the DBA be as widely experienced, and as widely read, as possible. Readings should include DBA manuals, trade journals, and possibly newsgroups or mailing lists.

  1. Weekly Procedures
    1. Look for objects that break rules
    2. For each object-creation policy (naming convention, storage parameters, etc.) have an automated check to verify that the policy is being followed.

      1. Every object in a given tablespace should have the exact same size for NEXT_EXTENT, which should match the tablespace default for NEXT_EXTENT. As of 12/14/98, default NEXT_EXTENT for DATAHI is 1 gig (1048576 bytes), DATALO is 500 mb (524288 bytes), and INDEXES is 256 mb (262144 bytes).
        1. To check settings for NEXT_EXTENT, run nextext.sql.
        2. To check existing extents, run existext.sql

         

      2. All tables should have unique primary keys.
        1. To check missing PK, run no_pk.sql.
        2. To check disabled PK, run disPK.sql.
        3. All primary key indexes should be unique. Run nonuPK.sql to check.

         

      3. All indexes should use INDEXES tablespace. Run mkrebuild_idx.sql.
      4. Schemas should look identical between environments, especially test and production.
        1. To check data type consistency, run datatype.sql.
        2. To check other object consistency, run obj_coord.sql.
    3. Look for security policy violations
    4. Look in SQL*Net logs for errors, issues
      1. Client side logs
      2. Server side logs
    5. Archive all Alert Logs to history
    6.  

    7. Visit home pages of key vendors
      1. Oracle Corporation
      2. http://www.oracle.com
        http://technet.oracle.com
        http://www.oracle.com/support
        http://www.oramag.com

      3. Quest Software
      4. http://www.quests.com

      5. Sun Microsystems

    http://www.sun.com

     

  2. Monthly Procedures
    1. Look for Harmful Growth Rates
      1. Review changes in segment growth when compared to previous reports to identify segments with a harmful growth rate.
    2. Review Tuning Opportunities
      1. Review common Oracle tuning points such as cache hit ratio, latch contention, and other points dealing with memory management. Compare with past reports to identify harmful trends or determine impact of recent tuning adjustments.
    3. Look for I/O Contention
      1. Review database file activity. Compare to past output to identify trends that could lead to possible contention.
    4. Review Fragmentation
      1. Investigate fragmentation (e.g. row chaining, etc.).
    5. Project Performance into the Future
      1. Compare reports on CPU, memory, network, and disk utilization from both Oracle and the operating system to identify trends that could lead to contention for any one of these resources in the near future.
      2. Compare performance trends to Service Level Agreement to see when the system will go out of bounds
    6. Perform Tuning and Maintenance
      1. Make the adjustments necessary to avoid contention for system resources. This may include scheduled down time or request for additional resources.

     

     

     

  3. Appendix
  4.  

    1. Daily Procedures
      1. Free.sql
      2. --

        -- free.sql

        --

        -- To verify free space in tablespaces

        -- Minimum amount of free space

        -- document your thresholds:

        -- <tablespace_name> = <amount> m

        --

        SELECT tablespace_name, sum ( blocks ) as free_blk , trunc ( sum ( bytes ) / (1024*1024) ) as free_m

        , max ( bytes ) / (1024) as big_chunk_k, count (*) as num_chunks

        FROM dba_free_space

        GROUP BY tablespace_name

         

      3. Space.sql
      4. --

        -- space.sql

        --

        -- To check free, pct_free, and allocated space within a tablespace

        --

        -- 11/24/98

        SELECT tablespace_name, largest_free_chunk

        , nr_free_chunks, sum_alloc_blocks, sum_free_blocks

        , to_char(100*sum_free_blocks/sum_alloc_blocks, '09.99') || '%'

        AS pct_free

        FROM ( SELECT tablespace_name

        , sum(blocks) AS sum_alloc_blocks

        FROM dba_data_files

        GROUP BY tablespace_name

        )

        , ( SELECT tablespace_name AS fs_ts_name

        , max(blocks) AS largest_free_chunk

        , count(blocks) AS nr_free_chunks

        , sum(blocks) AS sum_free_blocks

        FROM dba_free_space

        GROUP BY tablespace_name )

        WHERE tablespace_name = fs_ts_name

      5. Daily_01.sql
      6. --

        -- daily_01.sql

        --

        -- To analyze tables and indexes

        --

        -- 11/30/98

        BEGIN

        dbms_utility.analyze_schema ( '&OWNER', 'ESTIMATE', NULL, 5 ) ;

        END ;

        /

      7. nr_extents.sql
      8. --

        -- nr_extents.sql

        --

        -- To find out any object reaching <threshold>

        -- extents, and manually upgrade it to allow unlimited

        -- max_extents (thus only objects we *expect* to be big

        -- are allowed to become big)

        --

        -- 11/30/98

        SELECT e.owner, e.segment_type , e.segment_name , count(*) as nr_extents , s.max_extents

        , to_char ( sum ( e.bytes ) / ( 1024 * 1024 ) , '999,999.90') as MB

        FROM dba_extents e , dba_segments s

        WHERE e.segment_name = s.segment_name

        GROUP BY e.owner, e.segment_type , e.segment_name , s.max_extents

        HAVING count(*) > &THRESHOLD

        OR ( ( s.max_extents - count(*) ) < &&THRESHOLD )

        ORDER BY count(*) desc

         

      9. spacebound.sql

      --

      -- spacebound.sql

      --

      -- To identify space-bound objects. If all is well, no rows are returned.

      -- If any space-bound objects are found, look at value of NEXT extent

      -- size to figure out what happened.

      -- Then use coalesce (alter tablespace <foo> coalesce;).

      -- Lastly, add another datafile to the tablespace if needed.

      --

      -- 11/30/98

      SELECT a.table_name, a.next_extent, a.tablespace_name

      FROM all_tables a,

      ( SELECT tablespace_name, max(bytes) as big_chunk

      FROM dba_free_space

      GROUP BY tablespace_name ) f

      WHERE f.tablespace_name = a.tablespace_name

      AND a.next_extent > f.big_chunk

       

    2. Weekly Procedures
    3.  

      1. nextext.sql
      2. --

        -- nextext.sql

        --

        -- To find tables that don't match the tablespace default for NEXT extent.

        -- The implicit rule here is that every table in a given tablespace should

        -- use the exact same value for NEXT, which should also be the tablespace's

        -- default value for NEXT.

        --

        -- This tells us what the setting for NEXT is for these objects today.

        --

        -- 11/30/98

        SELECT segment_name, segment_type, ds.next_extent as Actual_Next

        , dt.tablespace_name, dt.next_extent as Default_Next

        FROM dba_tablespaces dt, dba_segments ds

        WHERE dt.tablespace_name = ds.tablespace_name

        AND dt.next_extent !=ds.next_extent

        AND ds.owner = UPPER ( '&OWNER' )

        ORDER BY tablespace_name, segment_type, segment_name

         

      3. existext.sql
      4. --

        -- existext.sql

        --

        -- To check existing extents

        --

        -- This tells us how many of each object's extents differ in size from

        -- the tablespace's default size. If this report shows a lot of different

        -- sized extents, your free space is likely to become fragmented. If so,

        -- this tablespace is a candidate for reorganizing.

        --

        -- 12/15/98

        SELECT segment_name, segment_type

        , count(*) as nr_exts

        , sum ( DECODE ( dx.bytes,dt.next_extent,0,1) ) as nr_illsized_exts

        , dt.tablespace_name, dt.next_extent as dflt_ext_size

        FROM dba_tablespaces dt, dba_extents dx

        WHERE dt.tablespace_name = dx.tablespace_name

        AND dx.owner = '&OWNER'

        GROUP BY segment_name, segment_type, dt.tablespace_name, dt.next_extent

         

      5. No_pk.sql
      6. --

        -- no_pk.sql

        --

        -- To find tables without PK constraint

        --

        -- 11/2/98

        SELECT table_name

        FROM all_tables

        WHERE owner = '&OWNER'

        MINUS

        SELECT table_name

        FROM all_constraints

        WHERE owner = '&&OWNER'

        AND constraint_type = 'P'

         

      7. disPK.sql
      8. --

        -- disPK.sql

        --

        -- To find out which primary keys are disabled

        --

        -- 11/30/98

        SELECT owner, constraint_name, table_name, status

        FROM all_constraints

        WHERE owner = '&OWNER' AND status = 'DISABLED’ AND constraint_type = 'P'

         

      9. nonuPK.sql
      10. --

        -- nonuPK.sql

        --

        -- To find tables with nonunique PK indexes. Requires that PK names

        -- follow a naming convention. An alternative query follows that

        -- does not have this requirement, but runs more slowly.

        --

        -- 11/2/98

         

        SELECT index_name, table_name, uniqueness

        FROM all_indexes

        WHERE index_name like '&PKNAME%'

        AND owner = '&OWNER' AND uniqueness = 'NONUNIQUE'

        SELECT c.constraint_name, i.tablespace_name, i.uniqueness

        FROM all_constraints c , all_indexes i

        WHERE c.owner = UPPER ( '&OWNER' ) AND i.uniqueness = 'NONUNIQUE'

        AND c.constraint_type = 'P' AND i.index_name = c.constraint_name

         

      11. mkrebuild_idx.sql
      12. --

        -- mkrebuild_idx.sql

        --

        -- Rebuild indexes to have correct storage parameters

        --

        -- 11/2/98

        SELECT 'alter index ' || index_name || ' rebuild '

        , 'tablespace INDEXES storage ( initial 256 K next 256 K ) ; '

        FROM all_indexes

        WHERE ( tablespace_name != 'INDEXES'

        OR next_extent != ( 256 * 1024 )

        )

        AND owner = '&OWNER'

        /

         

      13. datatype.sql
      14. --

        -- datatype.sql

        --

        -- To check datatype consistency between two environments

        --

        -- 11/30/98

         

        SELECT

        table_name,

        column_name,

        data_type,

        data_length,

        data_precision,

        data_scale,

        nullable

        FROM all_tab_columns -- first environment

        WHERE owner = '&OWNER'

        MINUS

        SELECT

        table_name,

        column_name,

        data_type,

        data_length,

        data_precision,

        data_scale,

        nullable

        FROM all_tab_columns@&my_db_link -- second environment

        WHERE owner = '&OWNER2'

        order by table_name, column_name

         

      15. obj_coord.sql

    --

    -- obj_coord.sql

    --

    -- To find out any difference in objects between two instances

    --

    -- 12/08/98

    SELECT object_name, object_type

    FROM user_objects

    MINUS

    SELECT object_name, object_type

    FROM user_objects@&my_db_link

     

     

     

     

     

  5. References
    1. Loney, Kevin Oracle8 DBA Handbook
    2. Cook, David Database Management from Crisis to Confidence [http://www.europa.com/~orapub]
    3. Cox, Thomas B. The Database Administration Maturity Model