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Della Charlotte Fisher
8 years ago
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2 Dr. Stephan Bühne Principal Technical Consultant Oracle SAP Solution Center Walldorf

3 Oracle Reorganisation

4 Why to reorganize Traditional Space Management New Automatic Space Mangement Locally Managed Tablespaces Using Parallel Processing

5 Why to Reorganise Free Up Disk Space 100,AB,.. 100,CD,.. 100,EF,.. 100,GH.. 100,IJ,..... Client Delete 100,AB,.. 100,CD,.. 100,EF,.. 100,GH,.. 100,IJ,.....? Number of Extents Space Fragmentation in Tablespace Archiving

6 Why to reorganize Traditional Space Management New Automatic Space Mangement Locally Managed Tablespaces Using Parallel Processing

7 Space Management Oracle: Insert/ Update Blocksize = 8192 Bytes Reserved for Updates Block-Header (~ 125 Byte) PCTFREE = 10% Insert up to PCTFREE ~ 7000 Bytes

8 Space Management Oracle: Delete Blocksize = 8192 Bytes Current Block Filling Level Block-Header (~ 125 Byte) PCTFREE = 10% ~ 4200 Bytes ~ 2800 Bytes PCTUSED = 40%

9 Archiving Procedure DB- Block DELETE FROM EDIDC WHERE CREDAT < PCTFREE 10% PCTFREE 10% DELETE... PCTUSED 40% DELETE FROM EDIDC WHERE CREDAT < and WERKS = 001 DB- Block PCTFREE 10% PCTFREE 10% DELETE... PCTUSED 40%

.. PCTUSED 40% DELETE FROM EDIDC WHERE CREDAT < 01.

10 Influence on distribution DELETE FROM EDIDC WHERE CREDAT < DELETE FROM EDIDC WHERE CREDAT < AND WERKS = 001

11 Why to reorganize Traditional Space Management New Automatic Space Mangement Locally Managed Tablespaces Using Parallel Processing

12 Automatic Space Management: Features Ease of Use => No PCTUSED, FREELISTS, FREELISTS Better space utilization => Freed space is reused immediatly Better concurrency handling => No contention on parallel processing Better performance => Faster seek operation for free space

reused immediatly Better concurrency handling => No contention on

13 Automatic Segment Space Management Extent #1 Extent #2 Extent #3 Extent #4 BMB L3 BMB L1 BMB L1 BMB L1 BMB L2 Segment Header BMB L2 BMB L1 BMB: Bit-Mapped Block

14 BMB: Internal Structure Freeness Status: nf1 1 nf2 1 nf3 0 nf4 11 First free datablock : 3 Bitmap block lock opcode 0 Locker xid: : 0x Highwater:: 0x ext#: 0 blk#: 16 ext size: 16 #blocks in seg. hdr's freelists: 0 #blocks below: 13 mapblk 0x offset: 0 HWM Flag: HWM Set DBA Ranges : x Length: 16 Offset: 0 0:Metadata 1:Metadata 2:Metadata 3:75-100% free 4:75-100% free 5:75-100% free 6:75-100% free 7:75-100% free 8:75-100% free 9:75-100% free 10:75-100% free 11:0-25% free 12:25-50% free 13:75-100% free 14:75-100% free 15:75-100% free nf1 = block is 0-25% free nf2 = block is 25-50% free nf3 = block is 50-75% free nf4 = block is % free

hdr's freelists: 0 #blocks below: 13 mapblk 0x00000000 offset: 0 HWM Flag: HWM Set -------------------------------------------------------- DBA Ranges :

15 Automatic Segment Space Management Extent BMB: Bit-Mapped Block BMB L1 BMB L1 BMB L1 Each BMB controls up to: => 16 blocks until the segment is 1Mb => 64 blocks until the segment is 32Mb => 256 blocks until the segment is 1Gb => 1024 blocks once segment is >1Gb

the segment is 1Mb => 64 blocks until the segment is 32Mb => 256

16 Automatic Segment Space Management Extent #1 Extent #2 Extent #3 Process 1 PID: BMB L3 BMB BMB Hash on PID BMB L2 BMB L2 Hash Hash BMB BMB Process 2 PID: 6789 BMB L1 BMB: Bit-Mapped Block

17 Influence on distribution DELETE FROM EDIDC WHERE CREDAT < DELETE FROM EDIDC WHERE CREDAT < AND WERKS = 001

18 Space Management Oracle: Insert/ Update Blocksize = 8192 Bytes Reserved for Updates Block-Header (~ 125 Byte) PCTFREE = 10% Insert up to PCTFREE ~ 7000 Bytes

19 Influence on distribution Performance? or Space?

20 Summary Automatic Space Management Improved performance for parallel load Less administration Easy to reuse space Increased distribution on blocks

21 Why to reorganize Traditional Space Management New Automatic Space Mangement Locally Managed Tablespaces Using Parallel Processing

22 Locally Managed Tablespaces Dictionary Managed Insert, Update, Delete System Tablespace FET$, UET$ Locally Managed System Tablespace

23 Internal Structure of Locally Managed TBS Uniform Size: All Extents have the same size = Extent is FREE 1 = Extent is USED

24 Internal Structure of Locally Managed TBS Autoallocate: 5 different extent sizes will be used = Extent is FREE 1 = Extent is USED 1 MB 1 MB 1 MB 1 MB... 8 MB... 8 MB MB MB MB 64 MB 1 MB 8 MB 1 MB 64 k 1 MB 8 MB 32 MB 64 MB

25 Advantages of Locally Managed Tablespaces No Initial or Next Extent Definition necessary No space fragmentation, forced by very different extent sizes (16K 2GB) Better usage of available space within the tablespace No Extent limitation Number of Extents has no impact on the system performance Better performance during insert/ delete operations and parallel load

26 Reorganisation Methods Export/ Import Create Table As Select (CTAS) Online-Index Reorganisation Online-Table Reorganisation (Oracle 9i only)

27 Why to reorganize Traditional Space Management New Automatic Space Mangement Locally Managed Tablespaces Using Parallel Processing

28 Parallel Query: FTS & Sorting Server Set 2 (Consumers) Server Set 1 (Producers) Table: Parallel Degree 2 100,ABCDEF, ,GHRSFG,2346 Direct Read 100,JFDSSF, ,KJZUDG,2348 Parallel Server Process #3 Parallel Server Process #1 (ROWID) 100,KUETSIT, ,AIOURT, ,AHJKGD, ,FGDFGF, ,OIUTAT,7345 Query Coordinator (Shadow Process) 100,IOUITAD, ,TXYCVB, ,POIUFS, ,POFSFR,9865 Direct Read 100,IUTADP, ,IIOPFAR,1235 Parallel Server Process #4 Parallel Server Process #2 (ROWID) 100,POTJAD, ,LKGJFS, ,POIUTA, ,BMKDA, ,FJKAER, ,OÜAPDF, ,OSDPDF,2408

29 Parallel Query: Create Index Index File REDO-Log Server Set 2 (Consumers) Direct Write/ Direct Read Server Set 1 (Producers) Table: Parallel Degree 2 Direct Read 100,ABCDEF, ,GHRSFG, ,JFDSSF, ,KJZUDG,2348 Logging Parallel Server Process #3 Parallel Server Process #1 (ROWID) 100,KUETSIT, ,AIOURT, ,AHJKGD, ,FGDFGF, ,OIUTAT,7345 Query Coordinator (Shadow Process) 100,IOUITAD, ,TXYCVB, ,POIUFS, ,POFSFR,9865 REDO-Log Logging Parallel Server Process #4 Parallel Server Process #2 Direct Read (ROWID) 100,IUTADP, ,IIOPFAR, ,POTJAD, ,LKGJFS, ,POIUTA, ,BMKDA,5555 Index File Direct Write/ Direct Read 100,FJKAER, ,OÜAPDF, ,OSDPDF,2408

Oracle DBA Course Contents

Oracle DBA Course Contents Overview of Oracle DBA tasks: Oracle as a flexible, complex & robust RDBMS The evolution of hardware and the relation to Oracle Different DBA job roles(vp of DBA, developer DBA,production