CDC & Streams Performance Test

Uli Bethke Change Data Capture

Scenarios Objective of the Streams Performance Test was to identify risks and bottlenecks for CDC and Streams. The following items were of particular interest to us: Identify bottlenecks for batch jobs with a low commit frequency, i.e. transactions that modify large numbers of records without committing frequently. We needed to know this because we have low commit frequency batch jobs ...

Asynch CDC: Delete old archived redo logs

Uli Bethke Oracle

The following steps need to be taken to be able to delete archived redo logs that are no longer required by the CDC capture process: 1. Determine the new first_scn for your capture process

As per Oracle documentation: This query "determines a new first_scn value that is greater than the original first_scn value and less than or equal to ...

Asynch CDC: Waiting For Dictionary Redo

Uli Bethke Oracle

I have come across (so far) four scenarios that show capture process "hanging" as WAITING FOR DICTIONARY REDO. 1. Wrong first_scn supplied for create_autolog_change_source: The first_scn when building the the data dictionary in the redo log via dbms_capture_adm.build does not match the first_scn when creating the change source on the downstream server. You need to supply the first_scn of the ...

Book Review: Inmon - DW 2.0. The Architecture for the next Generation of Data Warehousing

Uli Bethke DW Design

Get it from Amazon.co.uk Get it from Amazon.com First of all, this book is not written with the DW novice in mind. Some of the chapters require a thorough understanding of DW theory and concepts. Generally I found the book useful and I got some ideas that I will apply in one of my next projects. The biggest weakness of ...