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R3load version 7.00 introduces new option related to DB2 compression that automate the necessary steps to compress data during import and also improves the quality of the compression dictionary and the compression rates.

 

The available compression options:

1. COMPRESS          :  It is compatible with the option of R3load 6.40

2. COMPRESS_ALL    :  R3load creates tables with the COMPRESS YES option.

3. FULL_COMPRESS  :  Tables were crested with COMPRESS YES option,

                                 R3load first loads all the data into tables and then   

                                 triggered reorganization compresses the tables.

4. SAMPLED             :  R3load imports only a sample of data into tables, for

                                 example, every hundredth row from the export file. A

                                 subsequently triggered reorganization compresses the

                                 partially loaded tables. R3laod stops on error after this  

                                 step and must be restarted without the COMPRESS option 

                                 to load the complete set of data.

Full load and subsequent compression using R3load

To achieve an optimal compression ratio together with automation of the compression process, use the following R3load command:

R3load -loadprocedure fast LOAD:FULL_COMPRESS_ALL

This option creates tables with the COMPRESS YES option, loads all data, and performs a subsequent reorganization of all tables, rebuild the dictionary and compress data.

Execute R3load as follows:Look at the R3load log files which will contain the following information:

[…]

(DB) INFO: connected to DB

(DB6) INFO: COMPRESS YES is set during table creation.

(DB6) INFO: If row compression is active, REORG will be triggered after all data has been inserted.

[…]

(DB6) Using LOAD API for table ACCTIT

(DB6) INFO: Table ACCTIT reorganized to create compression dictionary

(IMP) INFO: import of ACCTIT completed (11505376 rows) #20100715191823

(DB) INFO: disconnected from DB

/usr/sap/BM2/SYS/exe/run/R3load: job completed

/usr/sap/BM2/SYS/exe/run/R3load: END OF LOG: 20100715191824

Advantages of this uncompressed load are:  Automatic process for compressing tables and optimal compression ratio. And the disadvantages of this load procedure are: Tables grow beyond their optimal compressed sizes before the final compression step. We recommend that you reduce the high water mark after compression. & higher import runtime (full import + full reorganization).</p>

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