Category Archives: Indexing

Oracle Indexing

Indexing is one of the most frequent approaches when resolving query performance issues raised within a database (though not necessary the right approach, but we can pick this up later). However, in order to better use indexing strategies, we should … Continue reading

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Oracle Index Organized Table(IOT)

What is an IOT? An IOT implies having your entire table indexed, within the same B-Tree structure. Should be used for larger scale tables or dimensions, highly used within the database. How to? Accessing the data is done via the … Continue reading

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Oracle Function Based Index

What is a Function-Based Index? A function-based index is an index created on the result of a function or expression. This type of index is more used for situations with atypical searches on the specified columns (e.g. search on an … Continue reading

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Oracle Bitmap Index

Common usage of Bitmap Indexes is a data warehousing environment. This implies large amounts of data, high level of ad-hoc queries but a low level of concurrent DLM transactions. Why to use? reduced response time reduced storage requirements compared to other … Continue reading

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Buffer Busy Waits – Reverse Key Index – Demo

We discussed earlier about indexing, and specifically reverse key indexing. I mentioned that is a solution for buffer busy waits on numerical consecutive inserted keys (like the sequence based generated ones) . This post will test that solution. For regular … Continue reading

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Oracle Reverse Index

This is one of the least used Oracle indexes I’ve encountered in a data-warehousing environment. However, a very good instrument in performance problems on OLTPs. To understand a reverse key index, we must first look at the regular b-tree index … Continue reading

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Oracle: Partitioning and Indexes 

As I’ve been presenting in the last couple of posts on partitioning, one of the major benefits of this database option is basically the selectivity when filtering on the partition key, what we currently call partition pruning. Now, what we’ve … Continue reading

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