If you you want to get an idea how some feature may be implemented by Oracle, then you ought to have a look for patents. Here are several examples I find quite interesting and containing valuable information:
- Method and apparatus for reapplying changes to a database – gives you an algorithm how Oracle optimizes recovery process
- Method and mechanism for efficient implementation of ordered records – another redo-related patent with the title hiding concept of multiple redo log buffers
- Method and mechanism for relational access of recovery logs in a database system – basically it’s describing LogMiner
- METHOD AND SYSTEM FOR IMPLEMENTING EFFICIENT CURSOR PRUNING – a very good-looking patent that describes how Oracle handles sharing of the child cursors nicely. Actually after reading this I realized that V$SQL_SHARED_CURSOR isn’t just an informational data supplied for diagnostic purpose, but rather it’s used and supported by Oracle to minimize number of comparisons while searching for a child with the required properties.
- EXTENDED CURSOR SHARING – this one is also on the topic of cursor sharing features related to adaptive optimization in run-time
- Compilation and processing a parallel single cursor model – describes the way in which a database can build and use parallel cursor without additional slave SQL. This is what Oracle does since 10g.
The list can go on. Just use “assignee:oracle” in the search box if you want to see Oracle’s patents only. What I like the most in these documents is they are unique. You will rarely find such a precisely described algorithms with block diagrams describing inner workings of a potential database system. Of course the information in patents is not the exact features description, nevertheless I find it quite useful.