Обсуждение: Need help with full text index configuration
I have some data that can be searched, and it looks like the parser is making some assumptions about the data that
aren'ttrue in our case and I'm trying to figure out how to exclude a token type. I haven't been able to find the
answerto my question so far, so I thought I would ask here.
The data I have are english words, and sometimes there are words separated by a / without spaces. The parser finds
thesethings and tokenizes them as files. I'm sure in some situations that's the right assumption, but based on my
data,I know there will never be a file name in the column.
For example instead of the parser recognizing three asciiword it recognizes one asciiword and one file. I'd like a
wayto have the / just get parsed as blank.
db=# select * from ts_debug('english','maybe five/six');
alias | description | token | dictionaries | dictionary | lexemes
-----------+-------------------+----------+----------------+--------------+------------
asciiword | Word, all ASCII | maybe | {english_stem} | english_stem | {mayb}
blank | Space symbols | | {} | |
file | File or path name | five/six | {simple} | simple | {five/six}
(3 rows)
I thought that maybe I could create a new configuration and drop the file mapping, but that doesn't seem to work
either.
db=# CREATE TEXT SEARCH CONFIGURATION public.testd ( COPY = pg_catalog.english );
CREATE TEXT SEARCH CONFIGURATION
db=# ALTER TEXT SEARCH CONFIGURATION testd DROP MAPPING FOR file;
ALTER TEXT SEARCH CONFIGURATION
db=# SELECT * FROM ts_debug('testd','mabye five/six');
alias | description | token | dictionaries | dictionary | lexemes
-----------+-------------------+----------+----------------+--------------+---------
asciiword | Word, all ASCII | mabye | {english_stem} | english_stem | {maby}
blank | Space symbols | | {} | |
file | File or path name | five/six | {} | |
(3 rows)
Is there anyway to do this?
Thanks for the help in advance. I'm running 8.4.4
Brian Hirt <bhirt@mobygames.com> writes:
> For example instead of the parser recognizing three asciiword it recognizes one asciiword and one file. I'd like a
wayto have the / just get parsed as blank.
AFAIK the only good way to do that is to write your own parser :-(.
The builtin parser isn't really configurable. (If you didn't mind
maintaining a private version you could patch its state transition
table manually, but that seems like a PITA.)
For the case at hand it could be a pretty thin frontend to the builtin
text parser --- just change / to space and then call the builtin one.
contrib/test_parser/ might help you get started.
regards, tom lane
Tom, Thanks for the quick reply. Doing a frontend mapping was my next option since I really don't care about / and the abilityto search on it. Preventing the parser from using the file tokenizer seemed like a better solution so I wanted togo down that path first (there are other false hits i was worried about too, like email, etc) I'm really confused about what "ALTER TEXT SEARCH CONFIGURATION dict DROP MAPPING FOR file" actually does. The documentationseems to make it sound like it does what I want, but I guess it does something else. --brian On Jul 28, 2010, at 2:06 PM, Tom Lane wrote: > Brian Hirt <bhirt@mobygames.com> writes: >> For example instead of the parser recognizing three asciiword it recognizes one asciiword and one file. I'd like a wayto have the / just get parsed as blank. > > AFAIK the only good way to do that is to write your own parser :-(. > The builtin parser isn't really configurable. (If you didn't mind > maintaining a private version you could patch its state transition > table manually, but that seems like a PITA.) > > For the case at hand it could be a pretty thin frontend to the builtin > text parser --- just change / to space and then call the builtin one. > contrib/test_parser/ might help you get started. > > regards, tom lane >
Brian Hirt <bhirt@mobygames.com> writes:
> I'm really confused about what "ALTER TEXT SEARCH CONFIGURATION dict DROP MAPPING FOR file" actually does. The
documentationseems to make it sound like it does what I want, but I guess it does something else.
No, it doesn't affect the parser's behavior at all. So foo/bar will
still be parsed as a "file" token. What the above results in is
dropping file tokens on the floor afterwards, instead of passing them
to some dictionary. In general the mapping stuff just controls what
dictionary(s) tokens produced by the parser will be routed to.
regards, tom lane
Brian,
you have two options:
1. Use your own parser (just modify default)
2. Use replace function, like
postgres=# select to_tsvector( replace('qw/er/ty','/',' '));
to_tsvector
----------------------
'er':2 'qw':1 'ty':3
(1 row)
Oleg
On Wed, 28 Jul 2010, Brian Hirt wrote:
> I have some data that can be searched, and it looks like the parser is making some assumptions about the data that
aren'ttrue in our case and I'm trying to figure out how to exclude a token type. I haven't been able to find the
answerto my question so far, so I thought I would ask here.
>
> The data I have are english words, and sometimes there are words separated by a / without spaces. The parser finds
thesethings and tokenizes them as files. I'm sure in some situations that's the right assumption, but based on my
data,I know there will never be a file name in the column.
>
> For example instead of the parser recognizing three asciiword it recognizes one asciiword and one file. I'd like a
wayto have the / just get parsed as blank.
>
> db=# select * from ts_debug('english','maybe five/six');
> alias | description | token | dictionaries | dictionary | lexemes
> -----------+-------------------+----------+----------------+--------------+------------
> asciiword | Word, all ASCII | maybe | {english_stem} | english_stem | {mayb}
> blank | Space symbols | | {} | |
> file | File or path name | five/six | {simple} | simple | {five/six}
> (3 rows)
>
> I thought that maybe I could create a new configuration and drop the file mapping, but that doesn't seem to work
either.
>
> db=# CREATE TEXT SEARCH CONFIGURATION public.testd ( COPY = pg_catalog.english );
> CREATE TEXT SEARCH CONFIGURATION
> db=# ALTER TEXT SEARCH CONFIGURATION testd DROP MAPPING FOR file;
> ALTER TEXT SEARCH CONFIGURATION
> db=# SELECT * FROM ts_debug('testd','mabye five/six');
> alias | description | token | dictionaries | dictionary | lexemes
> -----------+-------------------+----------+----------------+--------------+---------
> asciiword | Word, all ASCII | mabye | {english_stem} | english_stem | {maby}
> blank | Space symbols | | {} | |
> file | File or path name | five/six | {} | |
> (3 rows)
>
>
> Is there anyway to do this?
>
> Thanks for the help in advance. I'm running 8.4.4
>
Regards,
Oleg
_____________________________________________________________
Oleg Bartunov, Research Scientist, Head of AstroNet (www.astronet.ru),
Sternberg Astronomical Institute, Moscow University, Russia
Internet: oleg@sai.msu.su, http://www.sai.msu.su/~megera/
phone: +007(495)939-16-83, +007(495)939-23-83