Documentation Source Text

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

chng {2018-02-00 (3.22.0)} {
<li> The output of [sqlite3_trace_v2()] now shows each individual SQL statement
     run within a trigger.
<li> Add the ability to read from [WAL mode] databases even if the application 
     lacks write permission on the database and its containing directory, as long as
     the -shm and -wal files exist in that directory.
<li> Added the [rtreecheck()] scalar SQL function to the [R-Tree extension].
<li> Added the [sqlite3_vtab_nochange()] and [sqlite3_value_nochange()] interfaces
     to help virtual table implementations optimize UPDATE operations.

  <li> The [https://sqlite.org/src/file/ext/misc/appendvfs.c|Append VFS] is a
       [VFS shim] that allows an SQLite database to be appended to some other
       file.  This allows (for example) a database to be appended to an
       executable that then opens and reads the database.
</ol>
<li> Query planner enhancements:
<ol type='a'>
  <li> The optimization that uses an index to quickly compute an
       aggregate min() or max() is extended to work with
       [indexes on expressions].
  <li> The decision of whether to implement a FROM-clause subquery
       as a co-routine or using [query flattener|query flattening]
       now considers whether
       the result set of the outer query is "complex" (if it
       contains functions or expression subqueries).  A complex result
       set biases the decision toward the use of co-routines.
  <li> The planner avoids query plans that use indexes with unknown
       collating functions.
  <li> The planner omits unused LEFT JOINs even if they are not the 
       right-most joins of a query.
</ol>
<li> Other performance optimizations:
<ol type='a'>
  <li> A smaller and faster implementation of text to floating-point
       conversion subroutine: sqlite3AtoF().
  <li> The [Lemon parser generator] creates a faster parser.
  <li> Use the strcspn() C-library routine to speed up the LIKE and

<tclscript>DisplayCode {
sqlite> (((.excel)))
sqlite> (((SELECT * FROM tab;)))
}</tclscript>

<p>
The command above writes the output of the query as CSV into a temporary
file, invokes the default handler for CSV files (usually the preferred
spreadsheet program such as Excel or LibreOffice), then deletes the
temporary file.  This is essentially a short-hand method of doing
the sequence of ".csv", ".once", and ".system" commands described above.

<p>
The ".excel" command is really an alias for ".once -x".  The -x option