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There are many compelling reasons to implement Oracle partitioning for larger databases, and Oracle partitioning has become the de-facto standard for systems over 500 gigabytes.  Oracle partitioning has many benefits to improve performance and manageability: Faster SQL – Oracle is partition-aware, and some SQL may improve is speed by several orders of magnitude (over 100x faster). Index range scans – Oracle partitioning physically sequences rows in index-order causing a dramatic improvement (over 10x faster) in the speed of partition-key scans. Full-table scans – Oracle partition pruning only accesses those data blocks required by the query. Table joins – Oracle partition-wise joins take the specific sub-set of the query partitions, causing huge speed improvements on nested loop and hash joins Updates – Oracle parallel query for partit

Oracle Parallel Query (formerly Oracle Parallel Query Option or PQO) allows one to break-up a given SQL statement so that its parts can run simultaneously on different processors in a multi-processor machine. Typical operations that can run in parallel are: full table scans, sorts, sub-queries, data loading etc. he foundation of Oracle Real Application Clusters revolves around parallelism. The original name for RAC was OPS, for Oracle Parallel Server. With RAC, it is possible for an intra-parallel operation to utilize the processors across the nodes, using the second argument in the Oracle PARALLEL hint.  This gives an additional degree of parallelism while executing in parallel. Oracle Parallel Query in a distributed environment: In a distributed environment, pieces of a table may reside on many remote servers. You can access all of the remote rows in a single q

The most expensive step in the SQL preparation process is the generation of the execution plan, particularly when dealing with a query with multiple joins. When RDBMs evaluates table join orders, it must consider every possible combination of tables. For example, a six-way table join has 720 (permutations of 6, or 6 * 5 * 4 * 3 * 2 * 1 = 720) possible ways that the tables can be joined together. In Oracle, optimizer_search_limit and optimizer_max_permutations parameters work together to place an upper limit on the number of permutations the optimizer will consider. But setting these values will not guarantee the best results. Hints for Your SQL Statement Hints are instructions that you include in your SQL statement for the optimizer. Using hints, you can specify join orders, types of access path, indexes to be used, and the intended optimization goals. You must place the hints within /*+ <h

RAC stands for Real Application Clusters. Oracle has a host of tools that facilitate scalability. Oracle RAC is commonly used for scalable Oracle solutions. Oracle Real Application Cluster (RAC) allows multiple nodes in a clustered environment to mount and open a single database that resides on shared disk storage. Should a single system (node) fail, the database service will still be available on the remaining nodes. RAC has the ability to quickly add an entire server to a cluster increasing the horsepower without effecting end-user response time. RAC is a recommended solution when you have saturated a single server. Grid Computing The idea of Grid computing arose from the need to solve highly-parallel computational problems that were beyond the processing capability of any single computer. Oracle Grid computing technology represents a significant rethinking of the traditional role of software infras

This being an interesting topic of discussion in SAAS community. The answer to the above question probably depends on whom you are talking to. As an old saying - the outcome of fight between an alligator and bear depends on where it take place. For the customers, they don't worry much about the architecture when: The SLA's are met- meaning the application scales as required Security and privacy of the data is maintained. The activity of one customer does not adversely affect another customer in terms of performance or security. Each customer is able to customize the application as they require. For the service provider the multi-tenancy matters as The architecture reduces the hardware cost- there will be significantly less number of boxes to manage. Far less number of da

Application scalability is the ability to increase application throughput by increasing the hardware support to the host application. Put it differently, if an application is able to handle 100 users on a single CPU hardware, then the application should on be able to handle 200 users when the number of process are doubled. Major server vendors continue to provide increasingly larger and more powerful machines. Recently, scale-out solutions, in the form of clusters of smaller machines, have gained increased acceptance. Vertical scalability is adding more memory and CPUs to a single box, or scaling up. Vertical scalability or scaling up is well suited for database tier. Horizontal scalability or scaling out is adding more boxes of similar memory and CPU. Scale out is ideal for web-tier. Researches have shown that "pure" scale-up approach is not very effective in usin