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When extracting trigrams from a regular expression for search of a GIN or GIST trigram index, it's useful to penalize (preferentially discard) trigrams that contain whitespace, since those are typically far more common in the index than trigrams not containing whitespace. Of course, this should only be a preference not a hard rule, since we might otherwise end up with no trigrams to search for. The previous coding tended to produce fairly inefficient trigram search sets for anchored regexp patterns, as reported by Erik Rijkers. This patch penalizes whitespace-containing trigrams, and also reduces the target number of extracted trigrams, since experience suggests that the original coding tended to select too many trigrams to search for. Alexander Korotkov, reviewed by Tom Lane |
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adminpack | ||
auth_delay | ||
auto_explain | ||
btree_gin | ||
btree_gist | ||
chkpass | ||
citext | ||
cube | ||
dblink | ||
dict_int | ||
dict_xsyn | ||
dummy_seclabel | ||
earthdistance | ||
file_fdw | ||
fuzzystrmatch | ||
hstore | ||
intagg | ||
intarray | ||
isn | ||
lo | ||
ltree | ||
oid2name | ||
pageinspect | ||
passwordcheck | ||
pg_archivecleanup | ||
pg_buffercache | ||
pg_freespacemap | ||
pg_prewarm | ||
pg_standby | ||
pg_stat_statements | ||
pg_test_fsync | ||
pg_test_timing | ||
pg_trgm | ||
pg_upgrade | ||
pg_upgrade_support | ||
pg_xlogdump | ||
pgbench | ||
pgcrypto | ||
pgrowlocks | ||
pgstattuple | ||
postgres_fdw | ||
seg | ||
sepgsql | ||
spi | ||
sslinfo | ||
start-scripts | ||
tablefunc | ||
tcn | ||
test_decoding | ||
test_parser | ||
test_shm_mq | ||
tsearch2 | ||
unaccent | ||
uuid-ossp | ||
vacuumlo | ||
worker_spi | ||
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.