Martin Klier


Oracle SQL: Optimizing a WHERE predicate inequality with a Function Based Index

Intro Recently, on Oracle, I saw a join of three tables, using three times TABLE ACCESS FULL and HASH JOIN, without an obvious reason. During separating and understanding its components, the following scenario turned out to be the culprit. select * from CARDTEST where OBJECT_ID<DATA_OBJECT_ID; The optimizer is unable to calculate the cardinality of […]

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