Why the In-Memory Column Store is not used (II)

Now after some research - I detected one simple rule for provoking In-Memory scans :

Why the In-Memory Column Store is not used (I)

yuuupie!

Now finally after a long period of waiting - and looking presentations and reading blogs I was able to do In-Memory databasing on my own. Having sampled some theoretical background how a a pure In-Memory Db works with SAP HANA; my expectations on the Oracle In-Memory Option were high. Also because Oracle promised it would work without code change, out of the box.

The setup

The Oracle database is located on Sun Solaris Machine (more...)

Oracle 12C – In-Memory Option Resources

Hi folks,

Introduced as an Option Oracles In-Memory option will change the world of databasing also like SAP HANA does; Since July the release is out but the search for resources and documentation is  poor;

Here some useful links I found.

Non-Oracle Resources

 

Oracle Documentation

Concepts (found a small passage) ...

 

 

just started the list - wiil enhance it - from time to (more...)

The empire strikes back!

About 3 years ago SAP started to create a new database engine, SAP HANA, with a pure In-Memory concept. SAP aggressively move it's new database to it's software stack. The database was not used as cache but for running Enterprise Application satisfying both OLTP and OLAP demands on the same database.  

As oracle announced the new Oracle 12c in late 2012 there the 'c' was for cloud based computing, means the simplification of creating (more...)

Conditional Unique Indexes


Matrix : What you must learn is that these rules are no different than rules of a computer system. Some of them can be bent, others can be broken. Understand?
 
Usually an unique index grants the uniqueness of all rows in a specific table which have non-null values; But (more...)

InfoQ : Running the Largest Hadoop DFS Cluster

Since I joined a Big Data Event : Frankfurter Datenbanktage 2013 - I started to take also a look to non-relational technics too. The RDBMS is not for every asepct the correct and fitting and fulfilling answer to all data related IT challenges. 

Frequently I wondered about how facebook (more...)

Learn from the smaller one’s : Native support for ENUM Types

Gerhard a colleague is dealing with postgres databases and was very suprised how many features are very oracle like. For example the same concept of Sequences as in Oracle. But then he detected the postgres enum native type support in postgres and asked me if the same feature would exist in Oracle.

When a Query runs slower on second execution – a possible side effect of cardinality feedback

After a successful migration from Oracle 10gR2 to Oracle 11gR2, I observed a very odd behavior executing a query; On first execution the query run fast - means 0.3 s; On second not faster but with tremendous reduced speed - approximate 20 s; Now this behavior is the opposite I experienced with complex queries (lot of joins, lot of predicates) , the first time of execution needs the extra cost of hard parsing and disk reads if the data is not in cache. the second time even the query run initial several seconds it run in a fraction of (more...)

Oracle 11GR2 Upgrade Resources

Currently I am testing/migrating an Oracle 11.2 Installation of our Appliction;

And found by the way a very helpful resource for Oracle Upgrades to 11GR2;

http://www.oracle.com/technetwork/database/upgrade/index.html

For example a real helpful and detailed document is this : 11g Release 2 Upgrade Workshop Presentation 

Cheers!

/Karl

Modifying an execution plan inside a View using a Query Block Hint (QB_NAME hint)

Optimizer Hints like Index, Cardinality, Ordered ... are local settings to a SQL statement. Local means the context given is the context of the SQL statement, the scope is local. If you query a View you cannot use for example an Index hint because the table names and aliases are hidden behind the view. So normal hinting would not work without  changing the view to add a hint.