tsearch in core patch, for review

We (Oleg and me) are glad to present tsearch2 in core of pgsql patch. In basic,
layout, functions, methods, types etc are the same as in current tsearch2 with a
lot of improvements:

- pg_ts_* tables now are in pg_catalog
- parsers, dictionaries, configurations now have owner and namespace similar to
other pgsql's objects like tables, operator classes etc
- current tsearch configuration is managed with a help of GUC variable
tsearch_conf_name.
- choosing of tsearch cfg by locale may be done for each schema separately
- managing of tsearch configuration with a help of SQL commands, not with
insert/update/delete statements. This allows to drive dependencies,
correct dumping and dropping.
- psql support with a help of \dF* commands
- add all available Snowball stemmers and corresponding configuration
- correct memory freeing by any dictionary

Work is sponsored by EnterpriseDB's PostgreSQL Development Fund

patch: http://www.sigaev.ru/misc/tsearch_core-0.27.gz

Sorry, but documentation is under heavy development now and temporary placed at
http://mira.sai.msu.su/~megera/pgsql/ftsdoc/ (changes quickly :) )
So, below there is a short overview of syntax.

Comments, suggestions, objections, questions will be appreciated. We are
planning to complete the patch and suggest to commit in HEAD soon.

SQL syntax:
CREATE FULLTEXT PARSER prsname (
START = funcname,
GETTOKEN = funcname,
END = funcname,
LEXTYPES = funcname
[ , HEADLINE = funcname ]
);

CREATE FULLTEXT DICTIONARY dictname (
LEXIZE = funcname
[ , INIT = funcname ]
[ , OPT = text ]
);

CREATE FULLTEXT DICTIONARY dictname [(
{ INIT = funcname |
LEXIZE = funcname |
OPT = text }
[, ... ]
)] LIKE template_dictname;
ALTER FULLTEXT DICTIONARY dictname SET OPT=text;

CREATE FULLTEXT CONFIGURATION cfgname (
PARSER = prsname
[, LOCALE = localename]
) [AS DEFAULT];

CREATE FULLTEXT CONFIGURATION cfgname [(
{ LOCALE = localename |
PARSER = prsname }
[, ...]
)] LIKE template_cfg [WITH MAP] [AS DEFAULT];

ALTER FULLTEXT CONFIGURATION cfgname SET
{ LOCALE=localename | PARSER=prsname } [, ...];
ALTER FULLTEXT CONFIGURATION cfgname SET AS DEFAULT;
ALTER FULLTEXT CONFIGURATION cfgname DROP DEFAULT;

CREATE FULLTEXT MAPPING ON cfgname FOR lexemetypename[, ...]
WITH dictname1[, ...];
ALTER FULLTEXT MAPPING ON cfgname FOR lexemetypename[, ...]
WITH dictname1[, ...];
DROP FULLTEXT MAPPING [IF EXISTS] ON cfgname FOR lexemetypename;

DROP FULLTEXT { DICTIONARY | PARSER | CONFIGURATION } [IF EXISTS] objname [
CASCADE | RESTRICT ];
ALTER FULLTEXT { DICTIONARY | PARSER | CONFIGURATION } objname RENAME TO newobjname;
ALTER FULLTEXT { DICTIONARY | PARSER | CONFIGURATION } objname OWNER TO newowner;
COMMENT ON FULLTEXT { DICTIONARY | PARSER | CONFIGURATION } objname IS text;

psql backslesh commands:
\dF [PATTERN] list fulltext configurations (add "+" for more detail)
\dFd [PATTERN] list fulltext dictionaries (add "+" for more detail)
\dFp [PATTERN] list fulltext parsers (add "+" for more detail)

--
Teodor Sigaev E-mail: teodor(at)sigaev(dot)ru
WWW: http://www.sigaev.ru/