Tagged Questions
1
vote
1answer
107 views
postgres GROUP BY and ORDER BY problem
I have two tables like this:
CREATE TABLE cmap5 (
name VARCHAR(2000),
lexemes TSQUERY
);
and
CREATE TABLE IF NOT EXISTS synonyms_all_gin_tsvcolumn (
cid int NOT NULL ...
3
votes
2answers
163 views
Full Text Search With PostgreSQL
i have a table with this rows:
Stickers
------------------------------------------------------
ID | Title |Keywords (ts_vector)
------------------------------------------------------
...
1
vote
1answer
73 views
Parse hyphenated word to unsigned integer
When tested to_tsvector on 'someword-123' with english full text config, I got the following result:
SELECT to_tsvector('someword-123');
to_tsvector
tsvector
--------------------
"'-123':2 ...
6
votes
1answer
105 views
Can I get the union of the a Postgres fulltext index?
I have a fulltext index on a table. Is it possible to retrieve the set of terms used in the index (gist or gin)? With weights if possible?
To clarify:
If I have the following table:
create table ...
3
votes
2answers
299 views
Slow ORDER BY with LIMIT
I have this query:
SELECT *
FROM location
WHERE to_tsvector('simple',unaccent2("city"))
@@ to_tsquery('simple',unaccent2('wroclaw'))
order by displaycount
I'm happy with it:
"Sort ...
3
votes
1answer
706 views
Postgres full text search with multiple columns, why concat in index and not at runtime?
I've come across full text search in postgres in the last few days, and I am a little confused about indexing when searching across multiple columns.
The postgres docs talk about creating a ts_vector ...
2
votes
2answers
251 views
What does “GIN doesn't support full index scans” mean?
I'm a RDBMS newbie and I have a PostgreSQL database of more than 50 millions lines, growing everyday. There is a column 'text', which contains human-generated text of around 20 words. I need to be ...
3
votes
2answers
364 views
ts_rank massively slows my query, how can I improve performance?
Here's the table definition
Table "public.kb_article_contents"
Column | Type | Modifiers
------------+----------+-----------
article_id | smallint | not null
contents | text | not ...
8
votes
3answers
669 views
How is LIKE implemented?
Can anyone explain how the LIKE operator is implemented in current database systems (e.g. MySQL or Postgres)? or point me to some references that explain it?
The naive approach would be to inspect ...
