Too Much Temp Space Used When Sorting A Small Lob Segment

(Doc ID 2364117.1)

Last updated on FEBRUARY 27, 2018

Applies to:

Oracle Database - Enterprise Edition - Version to [Release 11.2]
Information in this document applies to any platform.


Too much temp space used when running a simple SQL which sort a small LOB segment. The LOB segment is less than 1MB, but the sort takes more than 600MB temp space to store LOB_DATA; it is far more bigger than expected. (to sort 1MB LOB data, we need 600MB temp space, which is not reasonable):

A full testcase:





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