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| author | Tom Lane <tgl@sss.pgh.pa.us> | 2016-11-13 13:12:35 -0500 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2016-11-13 13:12:50 -0500 |
| commit | 6f932cac7a20995e07d8c546143c45793a5072a0 (patch) | |
| tree | 87234e6498a88b32ad2a9d21bce66ca6b011936c | |
| parent | cc302f375aed9c8987df6f6951e6b9da19fd4ada (diff) | |
| download | postgresql-6f932cac7a20995e07d8c546143c45793a5072a0.tar.gz postgresql-6f932cac7a20995e07d8c546143c45793a5072a0.zip | |
Doc: remove obsolete example.
The documentation for ts_headline() recommends using a sub-select to
avoid extra evaluations of ts_headline() in a query with ORDER BY+LIMIT.
Since commit 9118d03a8 this contortionism is unnecessary, so remove the
recommendation. Noted by Oleg Bartunov.
Discussion: <CAF4Au4w6rrH_j1bvVhzpOsRiHCog7sGJ3LSX0tY8ZdwhHT88LQ@mail.gmail.com>
| -rw-r--r-- | doc/src/sgml/textsearch.sgml | 14 |
1 files changed, 1 insertions, 13 deletions
diff --git a/doc/src/sgml/textsearch.sgml b/doc/src/sgml/textsearch.sgml index 5a70d7db802..2da75955d0b 100644 --- a/doc/src/sgml/textsearch.sgml +++ b/doc/src/sgml/textsearch.sgml @@ -1290,19 +1290,7 @@ query.', <para> <function>ts_headline</> uses the original document, not a <type>tsvector</type> summary, so it can be slow and should be used with - care. A typical mistake is to call <function>ts_headline</function> for - <emphasis>every</emphasis> matching document when only ten documents are - to be shown. <acronym>SQL</acronym> subqueries can help; here is an - example: - -<programlisting> -SELECT id, ts_headline(body, q), rank -FROM (SELECT id, body, q, ts_rank_cd(ti, q) AS rank - FROM apod, to_tsquery('stars') q - WHERE ti @@ q - ORDER BY rank DESC - LIMIT 10) AS foo; -</programlisting> + care. </para> </sect2> |