SOFTware is HARD

The logical model metadata The physical model metadata Note that Blue denotes the RDBMS metadata while Green denotes the NoSQL metadata.

A sequence number or an identity column guarantees the following: Number served is unique. Number served is sequential (ascending order) - Identity columns guarantees this; sequence number in Oracle RAC mode doesn't, unless ORDER is used. However: It does not guarantee the sequence is gap-free Sequence number/ identity columns do not partake in transactions Number loss/ gaps happen due to the following: Served number does not get utilised (typically due to transaction rollback) Server restart/ failures - database servers tend to cache sequences in memory for performance reasons. E.g. Oracle Sequence number set-up to be CACHEd in memory. According to Oracle 11gR2 Database Documentation : for the Sequence database concept, use of Oracle Sequence does not guarantee gap-free set of numbers.   If your application requires a gap-free set of numbers, then you cannot use Oracle sequences . You must serialize activities in the database using your own developed cod...

Emerging Technologies Cloud – for starters, for for non-business critical functions like CRM, email, collaboration Collaboration User experience Data deluge – what to do with so much data? Top Business Prioritises Business process improvement Reduce enterprise costs Increase use of information & analytics Improve workforce effectiveness Attract & retain new customers Business Intelligence State of Business Intelligence today – 20% of users in an organisation have BI in place; 80% of users do not. BI Solution Architecture Source system ETL processes Data Warehouse solution (ODS, Staging, Analysis cubes) Report presentation Microsoft Business Intelligence Strategy Familiarity – Office integration Collaborative – SharePoint integration Manageability – MS SQL Data Warehouse Trends in Data-Warehouse Increase in volume Reduce cost Adoption of appliances Move into MPP Desire for real-time analytics Realisation of the importance of data quality Microsoft...

What is an ODS? An environment: where data from different OLTP databases is integrated which provides a view of enterprise data that addresses operational challenges across more than one business function Characteristics of ODS: subject-oriented - catered to specific function or application (customer-centricity, risk management) integrated - from multiple legacy systems or new and legacy systems timely - data is continuously/ frequently being updated, typically more frequently than daily current - data is typically current with little history detailed - data is sufficiently detailed; not only at a summarized level central version of reference data ODS should be a separate data store from the data warehouse. Difference between ODS and Data Warehouse ODS DW Data Currency Current/ near-current Historical snapshot Data Loading Insert/ Update/ Deletion allowed Only loaded