Saturday Oct 26, 2013

Demantra Partitioning and the First PK Column

  We have found that it is necessary in Demantra to have an index that matches the partition key, although it does not have to be the PK.  It is ok
  to create a new index instead of changing the PK.

  For example, if my PK on SALES_DATA is (ITEM_ID, LOCATION_ID, SALES_DATE) and I decide partition by SALES_DATE, then I should add an index starting
  with the partition key like this: (SALES_DATE, ITEM_ID, LOCATION_ID).

  * Note that the first column of the new index matches the partition key.

  It might also be helpful to create a 2nd index with the other PK columns reversed (SALES_DATE, LOCATION_ID, ITEM_ID). Again, the first column
  matches the partition key.

Wednesday Oct 23, 2013

Demantra Performance Clustering Factor Out of Order Ratio TABLE_REORG CHECK_REORG (Doc ID 1594372.1)

Hello!   There is a new document available:

Demantra Performance Clustering Factor Out of Order Ratio TABLE_REORG CHECK_REORG (Doc ID 1594372.1)

Demantra Performance Clustering Factor Out of Order Ratio TABLE_REORG CHECK_REORG

The table reorganization can be setup to automatically run in version 7.3.1.5. 

In version 12.2.2 we run the TABLE_REORG.CHECK_REORG function at every appserver restart.
If the function recommends a reorg then we strongly encourage to reorg the database object. 
This is documented in the official docs.

In versions 7.3.1.3 and 7.3.1.4, the TABLE_REORG module exists and can be used.
It has two main functions that are documented in the Implementation Guide Supplement,
Release 7.3, Part No. E26760-03, chapter 4.

In short, if you are using version 7.3.1.3 or higher, you can check for the need to run a reorg by doing the following 2 steps:

1. Run TABLE_REORG.CHECK_REORG('T');
2. Check the table LOG_TABLE_REORG for recommendations

If you are on a version before 7.3.1.3, you will need to follow the instructions below to determine if you need to do a manual reorg.

How to determine if a table reorg is needed

1. It is strongly encouraged by DEV that You gather statistics on the required table.  The prefered percentage for the gather is 100%.

2. Run the following SQL to evaluate how table reorg might affect Primary Key (PK) based access:

 
SELECT ui.index_name,trunc((ut.num_rows/ui.clustering_factor)/(ut.num_rows/ut.blocks),2)
FROM user_indexes ui, user_tables ut, user_constraints uc
WHERE ui.table_name=ut.table_name
AND ut.table_name=uc.table_name
AND ui.index_name=uc.index_name
AND UC.CONSTRAINT_TYPE='P'
AND ut.table_name=upper('&enter_table_name');
 

3. Based on the result:

VALUE ABOVE 0.75 - DOES NOT REQUIRE REORG

VALUE BETWEEN 0.5 AND 0.75 - REORG IS RECOMMENDED

VALUE LOWER THAN 0.5 - IT IS HIGHLY RECOMMENDED TO REORG

Updates to the Demantra Partial Schema Exporter Tool, Patch 13930627, are Available.

Hello!  Updates to the Demantra Partial Schema Exporter Tool, Patch 13930627, are Available.
This is an updated re-release of the generic Partial Schema Exporter Tool.  The generic patch is for 7.3.1.x and 12.2.x.
TABLE_REORG was introduced in 7.3.1.3 12.2.0.  Therefore for 7.3.1.x the schema must be at 7.3.1.3 or above.

This is build 3 of the patch.

It contains fixes for the following bugs
- BUG 17495971 - DEMANTRA 12.2 - CUMULATIVE HISTORY NOT CORRECT
  It now only uses DATA_PUMP COMPRESSION only on Enterprise Edition for 11g and and up.

- Bug 17452153 - 1OFF:16086475:TRYING TO FILTER DROP DOWN IN A METHOD CALL USING MORE THAN 1 ATTR
  It now builds GL level filters with and without the GL id column where applicable.

These bugs are also fixed in 7.3.1.6 and 12.2.3.

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