Documentation Source Text

  set aChng($nChng) [list $date $desc $options]
  incr nChng
}

chng {2015-06-00 (3.8.10)} {
<li>Added the [sqldiff.exe] utility program for computing the differences between two
    SQLite database files.
<li>Added the <a href="fts3.html#matchinfo-y">y format string</a> to the 
    [matchinfo()] function of [FTS3].
<li>Performance optimizations for [ORDER BY], [VACUUM], [CREATE INDEX],
    [PRAGMA integrity_check], and [PRAGMA quick_check].
<li>Fix many obscure problems discovered while [SQL fuzzing].
<li>Identify all methods for important objects in the interface documentation.
    ([sqlite3_context|example])
<li>Made the [American Fuzzy Lop fuzzer]
    a standard part of SQLite's [testing|testing strategy].

  of integers in the returned array depends on both the query and the value
  of the second argument (if any) passed to the matchinfo function.

<p>
  The matchinfo function is called with either one or two arguments. As for
  all auxiliary functions, the first argument must be the special 
  [FTS hidden column]. The second argument, if it is specified, must be a text value
  comprised only of the characters 'p', 'c', 'n', 'a', 'l', 's', 'x', and 'y'.
  If no second argument is explicitly supplied, it defaults to "pcx". The
  second argument is referred to as the "format string" below.

<p>
  Characters in the matchinfo format string are processed from left to right. 
  Each character in the format string causes one or more 32-bit unsigned
  integer values to be added to the returned array. The "values" column in

      etc. In other words, the data for occurrences of phrase <i>p</i> in
      column <i>c</i> may be found using the following formula:
<pre>
          hits_this_row  = array&#91;3 * (c + p*cols) + 0&#93;
          hits_all_rows  = array&#91;3 * (c + p*cols) + 1&#93;
          docs_with_hits = array&#91;3 * (c + p*cols) + 2&#93;
</pre>
  <tr><td><a name="matchinfo-y">y</a> <td style="white-space:nowrap"><i>cols</i> * <i>phrases</i> 
    <td>
      For each distinct combination of a phrase and table column, the
      number of usable phrase matches that appear in the column. This is
      usually identical to the first value in each set of three returned by the
      'x' directive (see above). However, the number of hits reported by the
      'y' directive is zero for any phrase that is part of a sub-expression
      that does not match the current row. This makes a difference for