Understanding Oracle CLUSTER Joins
If two row sources being joined are actually tables that are part of a cluster, and if the join is an equijoin between the cluster keys of the two tables, then Oracle can use a CLUSTER join. Learn more.
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Understanding Oracle SORT-MERGE Joins
In a SORT-MERGE join, Oracle sorts the first row source by its join columns, sorts the second row source by its join columns, and then merges the sorted row sources together. Learn more.
Read MoreUnderstanding When Oracle Nested Loop Joins Are Ideal
NESTED LOOPS joins in Oracle are ideal when the driving row source is small and the joined columns of the inner row source are uniquely indexed or have a highly selective nonunique index. Learn more.
Read MoreFive Questions to Ask Before Tackling Oracle Join Issues
There are five primary join methods in Oracle, each with a unique set of features and limitations. Answer these 5 questions before you attack a potential join issue.
Read MoreChanges to the Oracle 11g Optimizer That Affect Tuning
Learn about some signiticant changes to the Oracle 11g optimzer that can affect SQL query tuning.
Read MoreUsing the EXISTS Function and the Nested Subquery in Oracle
It’s generally best to use the EXISTS function in Oracle instead of the IN function. Learn more.
Read MoreAbout Oracle Function-based Indexes
Function-based indexes in Oracle allow you to create an index based on a function or expression. Learn how this can impact performance.
Read MoreWhy Oracle Indexes Sometimes Get Suppressed
A modification of the column side of a WHERE clause in Oracle can result in index suppresseion. Learn a few alternatives for writing the query that do not modify the indexed column.
Read MoreUnderstand the Oracle Index Merge
In Oracle 11g you can merge two separate indexes and use the result of the indexes instead of going to the table from one of the indexes, which can speed performance. Learn more.
Read MoreHow to Use the New Oracle 11g Result Cache
If you are executing the same queries over and over, using the RESULT_CACHE hint in Oracle 11g can make subsequent queries run faster. Learn more.
Read MoreCaching a Table in Memory for Oracle
Caching a small, often-used table into Oracle memory ensures that the data isnt pushed out of memory by other data, but can have unexpected results. Learn more.
Read MoreMaking the Oracle Query “Magically” Faster
When a query is run multiple times in succession, it becomes faster because the data is cached in memory. This can make the query seem faster when it’s not. Learn why.
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