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jonathanlewis.wordpress.com | ||
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www.bobbydurrettdba.com
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| | | | | We have been discussing query tuning at work and I've come back to an example of the Oracle optimizer choosing the wrong plan due to an error in its calculation of the number of rows returned... | |
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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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iusoltsev.wordpress.com
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| | | | | ??????? ?????? ?? ??????? ??????????? 465 ??????! SELECT A.ID, A.LOGIN, A.NAME, A.LASTNAME, A.EMAIL FROM ACCOUNT A WHERE (A.LOGIN LIKE '%%') AND (A.NAME LIKE '%????????%' OR A.LASTNAME LIKE '%????????%') AND A.COMPANY_ID = 1 ORDER BY A.LOGIN ??? ???????, ????????? ???? ?? ??????? A.COMPANY_ID = 1 ???????? ??????? ???????????????? SQL> SELECT 'ALL' as "Condition", count(*) FROM ACCOUNT... | |
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nenadnoveljic.com
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| | | Oracle's heuristics previously avoided considering fixed tables for Join Predicate Pushdown (JPPD) transformation, leading to suboptimal plans. Enforcing predicate pushing into the view with the PUSH_PRED hint was a workaround. Oracle addressed this in the 21c release, evaluating fixed tables for JPPD. | ||