Build an index for substring search?

Question

I want to do general substring search among billions of strings. The requirement is a little different from general fulltext search because I want a query \"ubst\" also can

Answer 1

Sphinx does support effective substring searches since Version 2.0.1-beta, 22 apr 2011. Unfortunately as of today this support regards only beta versions, as mentioned here.

I made a try with 2.1.1 beta version. It seems to work correctly. See the manual entry for dictionary type, read about keywords type.

When I tried to use 2.0.6 release version, it fell back to inefficient crc index, giving the following warning during indexing:

WARNING: min_infix_len is not supported yet with dict=keywords; using dict=crc

My minimal configuration file:

source sour
{
  type = xmlpipe2
  xmlpipe_command = type C:\Temp\1\sphinx\input.xml
}

index inde
{
  source = sour
  path = testpa
  enable_star = 1
  dict = keywords
  charset_type = utf-8
  min_infix_len = 1
}