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tonyhasler.wordpress.com | ||
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orastory.wordpress.com
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| | | | | There have been some interesting posts from Marcin Przepiorowski and Kerry Osborne about mapping sql plan management (spm) baselines to a corresponding sql id. The key to sql plan baselines (DBA_SQL_PLAN_BASELINES) is SIGNATURE. And why signature? It's not just another change to the key to identifying sql statements (HASH_VALUE -> (NEW_)HASH_VALUE / OLD_HASH_VALUE -> SQL_ID).... | |
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jonathanlewis.wordpress.com
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| | | | | Following yesterday's note on SQL Profiles, someone asked how I detect that an opt_estimate hint had been used - with specific reference to the "index_scan" option. The reason for this particular choice is that other opt_estimate hints have a highly visible impact in the 10053 trace files, but this one doesn't. Here are a few... | |
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hourim.wordpress.com
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| | | | | The last Jonathan Lewis post on RAC Planswhich finished by the following phrases: "If you're going to hard-code hints into a query then take a look at the outline it generates when it does the right thing, and that will tell you about the 15 or so hints you've missed out. (Better still, consider generating... | |
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jonathanlewis.wordpress.com
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| | | I've lost count of the number of times I've reminded people that hinting (correctly) is hard. Even the humble /*+ index() */ hint and its close relatives are open to misunderstanding and accidental misuse, leading to complaints that "Oracle is ignoring my hint". Strange though it may seem, I'm still not 100% certain of what... | ||