Turns out brute force is *much* faster than SQLite :-)

Author: xolox

README.md

@@ -12,7 +12,7 @@ The notes.vim plug-in for the [Vim text editor] [vim] makes it easy to manage yo
  * **Searching notes:** `:SearchNotes keyword …` searches for keywords and `:SearchNotes /pattern/` searches for regular expressions
    * **Smart defaults:** Without an argument `:SearchNotes` searches for the word under the cursor (if the word starts with `@` that character will be included in the search, this means you can easily search for *@tagged* notes)
    * **Back-references:** The `:RelatedNotes` command find all notes referencing the current file
-   * A [Python 2] [python] script is included that accelerates keyword searches using an [SQLite] [sqlite] database
+   * A [Python 2] [python] script is included that accelerates keyword searches using a keyword index
    * The `:RecentNotes` command lists your notes by modification date, starting with the most recently edited note
  * **Navigating between notes:** The included file type plug-in redefines [gf] [gf] to jump between notes and the syntax script highlights note names as hyper links
  * **Writing aids:** The included file type plug-in contains mappings for automatic curly quotes, arrows and list bullets and supports completion of note titles using Control-X Control-U and completion of tags using Control-X Control-O
@@ -135,11 +135,11 @@ If you don't pass any arguments to the `:SearchNotes` command it will search for
 
 These mappings are currently not enabled by default because they conflict with already useful key mappings, but if you have any suggestions for alternatives feel free to contact me through GitHub or at <peter@peterodding.com>.
 
-#### Accelerated searching with Python and SQLite
+#### Accelerated searching with Python
 
-After collecting a fair amount of notes (say more than 5 MB) you will probably start to get annoyed at how long it takes Vim to search through all of your notes. To make searching more scalable the notes plug-in includes a Python script which uses a full text index of your notes stored in an SQLite database.
+After collecting a fair amount of notes (say more than 5 MB) you will probably start to get annoyed at how long it takes Vim to search through all of your notes. To make searching more scalable the notes plug-in includes a Python script which uses a persistent full text index of your notes stored in a file.
 
-The first time the Python script is run it will need to build the complete index which can take a few minutes, but after the index has been initialized updates and searches should be more or less instantaneous.
+The first time the Python script is run it will need to build the complete index which can take a moment, but after the index has been initialized updates and searches should be more or less instantaneous.
 
 ### The `:RelatedNotes` command
 
@@ -187,7 +187,6 @@ This software is licensed under the [MIT license] [mit].
 [shell]: http://www.vim.org/scripts/script.php?script_id=3123
 [slate]: http://code.google.com/p/vim/source/browse/runtime/colors/slate.vim
 [split]: http://vimdoc.sourceforge.net/htmldoc/windows.html#:split
-[sqlite]: http://sqlite.org/
 [tabedit]: http://vimdoc.sourceforge.net/htmldoc/tabpage.html#:tabedit
 [update]: http://vimdoc.sourceforge.net/htmldoc/editing.html#:update
 [utl]: http://www.vim.org/scripts/script.php?script_id=293

autoload/xolox/notes.vim

@@ -1,12 +1,12 @@
 " Vim auto-load script
 " Author: Peter Odding <peter@peterodding.com>
-" Last Change: November 21, 2011
+" Last Change: November 22, 2011
 " URL: http://peterodding.com/code/vim/notes/
 
 " Note: This file is encoded in UTF-8 including a byte order mark so
 " that Vim loads the script using the right encoding transparently.
 
-let g:xolox#notes#version = '0.12.12'
+let g:xolox#notes#version = '0.14'
 
 function! xolox#notes#shortcut() " {{{1
   " The "note:" pseudo protocol is just a shortcut for the :Note command.
@@ -551,7 +551,7 @@ function! s:run_scanner(keywords, matches) " {{{2
   if !(executable(python) && filereadable(scanner))
     call xolox#misc#msg#debug("notes.vim %s: The %s script isn't executable.", g:xolox#notes#version, scanner)
   else
-    let arguments = [scanner, g:notes_indexfile, g:notes_directory, a:keywords]
+    let arguments = [scanner, '--database', g:notes_indexfile, '--notes', g:notes_directory, a:keywords]
     call map(arguments, 'xolox#misc#escape#shell(v:val)')
     let output = xolox#misc#str#trim(system(join([python] + arguments)))
     if !v:shell_error
@@ -582,7 +582,7 @@ function! xolox#notes#get_fnames(include_shadow_notes) " {{{3
     let starttime = xolox#misc#timer#start()
     let pattern = xolox#misc#path#merge(g:notes_directory, '*')
     let listing = glob(xolox#misc#path#absolute(pattern))
-    call extend(s:cached_fnames, split(listing, '\n'))
+    call extend(s:cached_fnames, filter(split(listing, '\n'), 'filereadable(v:val)'))
     let s:have_cached_names = 1
     call xolox#misc#timer#stop('notes.vim %s: Cached note filenames in %s.', g:xolox#notes#version, starttime)
   endif

doc/notes.txt

@@ -38,8 +38,8 @@ notes in Vim:
  - Back-references: The |:RelatedNotes| command find all notes referencing the
    current file
 
- - A Python 2 [1] script is included that accelerates keyword searches using an
-   SQLite [2] database
+ - A Python 2 [1] script is included that accelerates keyword searches using a
+   keyword index
 
  - The |:RecentNotes| command lists your notes by modification date, starting
    with the most recently edited note
@@ -57,15 +57,15 @@ notes in Vim:
    highlighting using blocks marked with '{{{type … }}}' which allows you to
    embed highlighted code and configuration snippets in your notes
 
-Here's a screen shot of the syntax mode using the slate [3] color scheme:
+Here's a screen shot of the syntax mode using the slate [2] color scheme:
 
-    Syntax mode screen shot, see reference [4]
+    Syntax mode screen shot, see reference [3]
 
 ===============================================================================
                                                            *notes-install-usage*
 Install & usage ~
 
-Unzip the most recent ZIP archive [5] file inside your Vim profile directory
+Unzip the most recent ZIP archive [4] file inside your Vim profile directory
 (usually this is '~/.vim' on UNIX and '%USERPROFILE%\vimfiles' on Windows),
 restart Vim and execute the command ':helptags ~/.vim/doc' (use ':helptags
 ~\vimfiles\doc' instead on Windows). To get started execute |:Note| or ':edit
@@ -257,16 +257,16 @@ already useful key mappings, but if you have any suggestions for alternatives
 feel free to contact me through GitHub or at peter@peterodding.com.
 
 -------------------------------------------------------------------------------
-Accelerated searching with Python and SQLite ~
+                                       *notes-accelerated-searching-with-python*
+Accelerated searching with Python ~
 
 After collecting a fair amount of notes (say more than 5 MB) you will probably
 start to get annoyed at how long it takes Vim to search through all of your
 notes. To make searching more scalable the notes plug-in includes a Python
-script which uses a full text index of your notes stored in an SQLite
-database.
+script which uses a persistent full text index of your notes stored in a file.
 
 The first time the Python script is run it will need to build the complete
-index which can take a few minutes, but after the index has been initialized
+index which can take a moment, but after the index has been initialized
 updates and searches should be more or less instantaneous.
 
 -------------------------------------------------------------------------------
@@ -317,14 +317,14 @@ If for any reason you want to recreate the list of tags you can execute the
 ===============================================================================
 Other plug-ins that work well with the notes plug-in ~
 
- - The utl.vim [6] universal text linking plug-in enables links between your
+ - The utl.vim [5] universal text linking plug-in enables links between your
    notes, other local files and remote resources like web pages
 
- - My shell.vim [7] plug-in also enables easy navigation between your notes and
+ - My shell.vim [6] plug-in also enables easy navigation between your notes and
    environment like local files and directories, web pages and e-mail
    addresses
 
- - The VOoM [8] outlining plug-in should work well for notes if you use the
+ - The VOoM [7] outlining plug-in should work well for notes if you use the
    Markdown style headers starting with '#', however it has been reported that
    this combination may not always work so well in practice (sometimes losing
    notes!)
@@ -336,28 +336,27 @@ Contact ~
 If you have questions, bug reports, suggestions, etc. the author can be
 contacted at peter@peterodding.com. The latest version is available at
 http://peterodding.com/code/vim/notes/ and http://github.com/xolox/vim-notes.
-If you like the script please vote for it on Vim Online [9].
+If you like the script please vote for it on Vim Online [8].
 
 ===============================================================================
                                                                  *notes-license*
 License ~
 
-This software is licensed under the MIT license [10]. Copyright 2011 Peter
+This software is licensed under the MIT license [9]. Copyright 2011 Peter
 Odding <peter@peterodding.com>.
 
 ===============================================================================
                                                               *notes-references*
 References ~
 
 [1] http://python.org/
-[2] http://sqlite.org/
-[3] http://code.google.com/p/vim/source/browse/runtime/colors/slate.vim
-[4] http://peterodding.com/code/vim/notes/syntax.png
-[5] http://peterodding.com/code/vim/downloads/notes.zip
-[6] http://www.vim.org/scripts/script.php?script_id=293
-[7] http://www.vim.org/scripts/script.php?script_id=3123
-[8] http://www.vim.org/scripts/script.php?script_id=2657
-[9] http://www.vim.org/scripts/script.php?script_id=3375
-[10] http://en.wikipedia.org/wiki/MIT_License
+[2] http://code.google.com/p/vim/source/browse/runtime/colors/slate.vim
+[3] http://peterodding.com/code/vim/notes/syntax.png
+[4] http://peterodding.com/code/vim/downloads/notes.zip
+[5] http://www.vim.org/scripts/script.php?script_id=293
+[6] http://www.vim.org/scripts/script.php?script_id=3123
+[7] http://www.vim.org/scripts/script.php?script_id=2657
+[8] http://www.vim.org/scripts/script.php?script_id=3375
+[9] http://en.wikipedia.org/wiki/MIT_License
 
 vim: ft=help