Simplify loop logic in nodeIncrementalSort.c.
The inner loop in switchToPresortedPrefixMode() can be implemented
as a conventional integer-counter for() loop, removing a couple of
redundant boolean state variables. The old logic here was a remnant
of earlier development, but as things now stand there's no reason
for extra complexity.
Also, annotate the test case added by 82e0e2930 to explain why it
manages to hit the corner case fixed in that commit, and add an
EXPLAIN to verify that it's creating an incremental-sort plan.
Back-patch to v13, like the previous patch.
James Coleman and Tom Lane
Discussion: https://postgr.es/m/16846-ae49f51ac379a4cb@postgresql.org
Branch
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REL_13_STABLE
Details
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https://git.postgresql.org/pg/commitdiff/80dc07aa361b9b0028e49bbdf7a947775211b812
Modified Files
--------------
src/backend/executor/nodeIncrementalSort.c | 47 +++++++-------------------
src/test/regress/expected/incremental_sort.out | 15 ++++++++
src/test/regress/sql/incremental_sort.sql | 4 +++
3 files changed, 31 insertions(+), 35 deletions(-)