Just wondered why I got no results after executing a search via Sphinx and Thinking Sphinx. The problem was, that I used a negative value in a filter attribute and that Sphinx only supports unsigned integers:

Attributes are named. Attribute names are case insensitive. Attributes are not full-text indexed; they are stored in the index as is. Currently supported attribute types are:

  • unsigned integers (1-bit to 32-bit wide);
  • UNIX timestamps;
  • floating point values (32-bit, IEEE 754 single precision);
  • string ordinals (specially computed integers);
  • strings (since 1.10-beta);
  • MVA, multi-value attributes (variable-length lists of 32-bit unsigned integers).