Database Isolation Levels And Their Effects on Performance and Scalability

Some of us are not aware of the tremendous job databases perform, particularly their efforts to maintain the Isolation aspect of ACID. For example, some people believe that transactions are only related to data manipulation and not to queries, which is an incorrect assumption. Transaction Isolation is all about queries, and the consistency and completeness of the data retrieved by queries. This is how it works:

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Oracle and IBM databases: Disk-based vs In-memory databases

Current disk based RDBMS can run out of steam when processing large data. Can these problems be solved by migrating from a disk based RDBMS to an IMDB? Any limitations? To find out, I tested one of each from the two leading vendors who together hold 70% of the market share - Oracle's 11g and TimesTen 11g, and IBM's DB2 v9.5 and solidDB 6.3.

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