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Tom Lane 5fcb079858 Add sample text search dictionary templates and parsers, to replace the hard-to-maintain textual examples currently in the SGML docs. From Sergey Karpov.		18 years ago
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README.dict_int

Dictionary for integers
=======================

The motivation for this example dictionary is to control the indexing of
integers (signed and unsigned), and, consequently, to minimize the number of
unique words which greatly affect the performance of searching.

* Configuration

The dictionary accepts two options: 

  - The MAXLEN parameter specifies the maximum length (number of digits)
    allowed in an integer word.  The default value is 6.

  - The REJECTLONG parameter specifies if an overlength integer should be
    truncated or ignored. If REJECTLONG=FALSE (default), the dictionary returns
    the first MAXLEN digits of the integer. If REJECTLONG=TRUE, the
    dictionary treats an overlength integer as a stop word, so that it will
    not be indexed.

* Usage

1. Compile and install

2. Load dictionary

   psql mydb < dict_int.sql

3. Test it
 
   mydb# select ts_lexize('intdict', '12345678');
    ts_lexize
   -----------
    {123456}

4. Change its options as you wish

   mydb# ALTER TEXT SEARCH DICTIONARY intdict (MAXLEN = 4, REJECTLONG = true);
   ALTER TEXT SEARCH DICTIONARY

That's all.