Обсуждение: pgsql: Prevent inlining of multiply-referenced CTEs with outerrecursiv

Prevent inlining of multiply-referenced CTEs with outer recursive refs.

This has to be prevented because inlining would result in multiple
self-references, which we don't support (and in fact that's disallowed
by the SQL spec, see statements about linearly vs. nonlinearly
recursive queries).  Bug fix for commit 608b167f9.

Per report from Yaroslav Schekin (via Andrew Gierth)

Discussion: https://postgr.es/m/87wolmg60q.fsf@news-spur.riddles.org.uk

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/9476131278c7bfc435ad9a21fc8e981272ac0dd2

Modified Files
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src/backend/optimizer/plan/subselect.c  |  66 +++++++++++++++++++++
src/test/regress/expected/subselect.out | 100 ++++++++++++++++++++++++++++++++
src/test/regress/sql/subselect.sql      |  35 +++++++++++
3 files changed, 201 insertions(+)