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Previously, pull_varnos() took the relids of a PlaceHolderVar as being
equal to the relids in its contents, but that fails to account for the
possibility that we have to postpone evaluation of the PHV due to outer
joins. This could result in a malformed plan. The known cases end up
triggering the "failed to assign all NestLoopParams to plan nodes"
sanity check in createplan.c, but other symptoms may be possible.
The right value to use is the join level we actually intend to evaluate
the PHV at. We can get that from the ph_eval_at field of the associated
PlaceHolderInfo. However, there are some places that call pull_varnos()
before the PlaceHolderInfos have been created; in that case, fall back
to the conservative assumption that the PHV will be evaluated at its
syntactic level. (In principle this might result in missing some legal
optimization, but I'm not aware of any cases where it's an issue in
practice.) Things are also a bit ticklish for calls occurring during
deconstruct_jointree(), but AFAICS the ph_eval_at fields should have
reached their final values by the time we need them.
The main problem in making this work is that pull_varnos() has no
way to get at the PlaceHolderInfos. We can fix that easily, if a
bit tediously, in HEAD by passing it the planner "root" pointer.
In the back branches that'd cause an unacceptable API/ABI break for
extensions, so leave the existing entry points alone and add new ones
with the additional parameter. (If an old entry point is called and
encounters a PHV, it'll fall back to using the syntactic level,
again possibly missing some valid optimization.)
Back-patch to v12. The computation is surely also wrong before that,
but it appears that we cannot reach a bad plan thanks to join order
restrictions imposed on the subquery that the PlaceHolderVar came from.
The error only became reachable when commit
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.. | ||
adminpack | ||
amcheck | ||
auth_delay | ||
auto_explain | ||
bloom | ||
bool_plperl | ||
btree_gin | ||
btree_gist | ||
citext | ||
cube | ||
dblink | ||
dict_int | ||
dict_xsyn | ||
earthdistance | ||
file_fdw | ||
fuzzystrmatch | ||
hstore | ||
hstore_plperl | ||
hstore_plpython | ||
intagg | ||
intarray | ||
isn | ||
jsonb_plperl | ||
jsonb_plpython | ||
lo | ||
ltree | ||
ltree_plpython | ||
oid2name | ||
old_snapshot | ||
pageinspect | ||
passwordcheck | ||
pg_buffercache | ||
pg_freespacemap | ||
pg_prewarm | ||
pg_standby | ||
pg_stat_statements | ||
pg_surgery | ||
pg_trgm | ||
pg_visibility | ||
pgcrypto | ||
pgrowlocks | ||
pgstattuple | ||
postgres_fdw | ||
seg | ||
sepgsql | ||
spi | ||
sslinfo | ||
start-scripts | ||
tablefunc | ||
tcn | ||
test_decoding | ||
tsm_system_rows | ||
tsm_system_time | ||
unaccent | ||
uuid-ossp | ||
vacuumlo | ||
xml2 | ||
contrib-global.mk | ||
Makefile | ||
README |
The PostgreSQL contrib tree --------------------------- This subtree contains porting tools, analysis utilities, and plug-in features that are not part of the core PostgreSQL system, mainly because they address a limited audience or are too experimental to be part of the main source tree. This does not preclude their usefulness. User documentation for each module appears in the main SGML documentation. When building from the source distribution, these modules are not built automatically, unless you build the "world" target. You can also build and install them all by running "make all" and "make install" in this directory; or to build and install just one selected module, do the same in that module's subdirectory. Some directories supply new user-defined functions, operators, or types. To make use of one of these modules, after you have installed the code you need to register the new SQL objects in the database system by executing a CREATE EXTENSION command. In a fresh database, you can simply do CREATE EXTENSION module_name; See the PostgreSQL documentation for more information about this procedure.