Performance Tuning
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This post is the continuation of the previous part True price of high Clustering Factor: elapsed time, SGA and CPU This time let’s try to quantify the usage of the resources applying much broader index range scan.I’ll force retrieving 10% (1 million) of rows and will pay close attention to :Elapsed times with low and…
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This post is the continuation of the previous part. Clustering Factor – tests with block dumps My test environment comprises a table with 10 million rows and three columns with two indexes:– ID_SORTED (unique, generated as sorted) with the index on it– ID_MESS (almost unique, generated as scattered) with the index on it– PAD (filler…
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Analysis of joins with 10053 CBO trace This post continues from Part 1, diving deeper into the challenges posed by a suboptimal SQL query that led the optimizer to select a Cartesian Join combined with an overly expensive Hash Join.But do not treat its content as limited to just a Cartesian Join.It will also help…