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Buildfarm members ayu and tern have sometimes shown a different plan than expected for this query. I'd been unable to reproduce that before today, but I finally realized what is happening. If there is a concurrent open transaction (probably an autovacuum run in the buildfarm, but this can also be arranged manually), then the index entries for the rows removed by the DELETE a few lines up are not killed promptly, causing a change in the planner's estimate of the extremal value of ft2.c1, which moves the rowcount estimate for "c1 > 1100" by enough to change the join plan from nestloop to hash. To fix, change the query condition to "c1 > 1000", causing the hash plan to be preferred whether or not a concurrent open transaction exists. Since this UPDATE is tailored to be a no-op, nothing else changes. Report: https://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=ayu&dt=2021-06-09%2022%3A45%3A48 Report: https://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=ayu&dt=2021-06-13%2022%3A38%3A18 Report: https://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=tern&dt=2021-06-20%2004%3A55%3A36 |
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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_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.