8 Commits (4a14f13a0abfbf7e7d44a3d2689444d1806aa9dc)

Author	SHA1	Message	Date
Tom Lane	4a14f13a0a	Improve hash_create's API for selecting simple-binary-key hash functions. ... Previously, if you wanted anything besides C-string hash keys, you had to specify a custom hashing function to hash_create(). Nearly all such callers were specifying tag_hash or oid_hash; which is tedious, and rather error-prone, since a caller could easily miss the opportunity to optimize by using hash_uint32 when appropriate. Replace this with a design whereby callers using simple binary-data keys just specify HASH_BLOBS and don't need to mess with specific support functions. hash_create() itself will take care of optimizing when the key size is four bytes. This nets out saving a few hundred bytes of code space, and offers a measurable performance improvement in tidbitmap.c (which was not exploiting the opportunity to use hash_uint32 for its 4-byte keys). There might be some wins elsewhere too, I didn't analyze closely. In future we could look into offering a similar optimized hashing function for 8-byte keys. Under this design that could be done in a centralized and machine-independent fashion, whereas getting it right for keys of platform-dependent sizes would've been notationally painful before. For the moment, the old way still works fine, so as not to break source code compatibility for loadable modules. Eventually we might want to remove tag_hash and friends from the exported API altogether, since there's no real need for them to be explicitly referenced from outside dynahash.c. Teodor Sigaev and Tom Lane	11 years ago
Bruce Momjian	0a78320057	pgindent run for 9.4 ... This includes removing tabs after periods in C comments, which was applied to back branches, so this change should not effect backpatching.	12 years ago
Tom Lane	46a60abfe9	Suppress compiler warning in new contrib/pg_trgm code. ... MSVC doesn't seem to like it when a constant initializer loses precision upon being assigned. David Rowley	12 years ago
Tom Lane	80a5cf643a	Improve contrib/pg_trgm's heuristics for regexp index searches. ... 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	12 years ago
Bruce Momjian	7e04792a1c	Update copyright for 2014 ... Update all files in head, and files COPYRIGHT and legal.sgml in all back branches.	12 years ago
Robert Haas	cacbdd7810	Use appendStringInfoString instead of appendStringInfo where possible. ... This shaves a few cycles, and generally seems like good programming practice. David Rowley	12 years ago
Tom Lane	6f5b8beb64	Make contrib/pg_trgm also support regex searches with GiST indexes. ... This wasn't addressed in the original patch, but it doesn't take very much additional code to cover the case, so let's get it done. Since pg_trgm 1.1 hasn't been released yet, I just changed the definition of what's in it, rather than inventing a 1.2.	13 years ago
Tom Lane	3ccae48f44	Support indexing of regular-expression searches in contrib/pg_trgm. ... 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	13 years ago