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oracle_memory_management

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Oracle_Memory_Management

Options are:

  • Leave it completely up to the database

then just set memory_max_size and memory_target

  • Set minimum values for some components

then set values for pga_aggregate_target and/or sga_target

  • Set maximum values for some components

then set values for things like sga_max_size

Handy views to look at

0@@
1@@

produces something like this…

2@@

or

3@@

How memory is used (assuming conventional path reads - not direct path and dedicated server)

A user runs a query which either finds the blocks it needs already in the SGA or fetches the blocks<br /> needed from disk into the SGA.<br /> The desired rows/data is taken from those blocks in the SGA and pulled over to the PGA for sorting and/or grouping.<br /> If more than a “reasonable amount” of memory is required then the sorting and/or grouping spills over to TEMP space on disk and ultimately returns the rows to the user.<br />

References

oracle_memory_management.1544273361.txt.gz · Last modified: 2018/12/08 12:49 by 0.0.0.0

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