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* Fix regexport.c to behave sanely with lookaround constraints.Tom Lane2017-04-13
| | | | | | | | | | | | | | | | | | | | regexport.c thought it could just ignore LACON arcs, but the correct behavior is to treat them as satisfiable while consuming zero input (rather reminiscently of commit 9f1e642d5). Otherwise, the emitted simplified-NFA representation may contain no paths leading from initial to final state, which unsurprisingly confuses pg_trgm, as seen in bug #14623 from Jeff Janes. Since regexport's output representation has no concept of an arc that consumes zero input, recurse internally to find the next normal arc(s) after any LACON transitions. We'd be forced into changing that representation if a LACON could be the last arc reaching the final state, but fortunately the regex library never builds NFAs with such a configuration, so there always is a next normal arc. Back-patch to 9.3 where this logic was introduced. Discussion: https://postgr.es/m/20170413180503.25948.94871@wrigleys.postgresql.org
* Update copyright for 2015Bruce Momjian2015-01-06
| | | | Backpatch certain files through 9.0
* Update copyright for 2014Bruce Momjian2014-01-07
| | | | | Update all files in head, and files COPYRIGHT and legal.sgml in all back branches.
* Support indexing of regular-expression searches in contrib/pg_trgm.Tom Lane2013-04-09
This works by extracting trigrams from the given regular expression, in generally the same spirit as the previously-existing support for LIKE searches, though of course the details are far more complicated. Currently, only GIN indexes are supported. We might be able to make it work with GiST indexes later. The implementation includes adding API functions to backend/regex/ to provide a view of the search NFA created from a regular expression. These functions are meant to be generic enough to be supportable in a standalone version of the regex library, should that ever happen. Alexander Korotkov, reviewed by Heikki Linnakangas and Tom Lane