Karl Reitschuster's Oracle Space

Terracotta - the return of OODBMS?

Karl Reitschuster — Fri, 12 Dec 2008 07:04:18 +0000

Do you remember?

About 10 years ago OODBMS (Poet, Gemstone, Versant, ...) seemed to be starting to replace RDBMS; The idea for using OODBMS was simple - if the programming model is OOP why not persist Objects with an OODBMS directly instead of populating it's properties and class hierarchy into a couple of tables? It was the reason Oracle 8 came with object relational features; But they (OODBMS) failed for following reason:

Tanel Poders - Snap it!!!

Karl Reitschuster — Mon, 10 Nov 2008 15:34:01 +0000

Tanel Poder holds a 2 day session in Düsseldorf last week; This was not my first Tuning/Troubleshooting training. But it was extraordinary what Tanel showed us when usual ways would not work

Oracle 12 the Green Database - Oracle 12 Eco

Karl Reitschuster — Tue, 14 Oct 2008 11:54:55 +0000

Now living in a time of financial crisis and a growing gap of natural resources
a new paradigma - a new database paragdima is needed.

For Oracle 12 i think this could be Oracle 12 Eco;

Setting DBMS_STATS Environment

Karl Reitschuster — Wed, 01 Oct 2008 14:05:24 +0000

Hi Reader,
with Oracle 10g all default parameters of the DBMS_STATS package are defined as default in the data dictionary accessible with the DBMS_STATS GET_PARAM Method :

Tuning Leading '%' Queries - a simple approach

Karl Reitschuster — Fri, 19 Sep 2008 13:42:47 +0000

Hi reader,

usually queries using LIKE and leading '%' cannot be indexed. So an idea would be to mirror the string content with the string reverse function to be able to put the '%' operator at the end :

Cardinality and Pipelined Functions - Ugly!

Karl Reitschuster — Mon, 04 Aug 2008 09:27:11 +0000

Dear reader,

pipelined functions are very comfortable to process incoming data and to return it as structured result set. For this reason they are frequently used in SQL; But be carefully if you join result sets from pipelined function with other tables.

The Oracle optimizer usually uses gathered table statistics to calculate the cardinality of a join operation; For a result set originated in a pipeline function it has no statistics to evaluate and hence could try to get another path to the data.

Following SQL retrieves internal employee GUID's from external Id's passed as comma delimited string.