oracle11g - Can anyone help me with performance tuning algorithms (queries) for oracle 11g express? -

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i lost finding examples or algorithms showing use of performance tuning oracle 11g express or how used in oracle. have been looking @ youtube videos of them mention tuning , dont show examples or use oracle cmd. (if done in oracle cmd want know how performance tuning process)

as quick , dirty way started - run explain_plan tell how oracle thinks execute query (in practice different) , doing full table scan instead of hitting index , appropriate go , create indexes on necessary fields , check explain_plan output again. see oracle says use index rather doing full table scan etc.

other things watch out full table scans forced calling functions inside sql. if use rtrim () cost based optimizer has no realistic way know data after calling function can't job , forces full table scan impacting performance. if necessary can either inline function in sql statement or create index on function_name_here(column). place watch out when oracle automatic type conversion. if have data in 1 column number being joined on table containing same data column nvarchar instance, oracle automatically insert tonumber() function type conversion needs to. can cause full table scan.

that's @ least pointers on absolute basics , / how started.

if want easy way view explain plan download sql developer, right click on query , choose explain_plan menu.


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