Documentation Source Text

are the more significant and bits taken from the later bytes. </p>

<p>The format of a cell depends on which kind of b-tree page the cell
appears on.  The following table shows the elements of a cell, in
order of appearance, for the various b-tree page types.</p>

<blockquote><dl>
<dt><p>Table B-Tree Leaf Cell (header 0x0d):</p></dt>
<dd><p><ul>
<li>A varint which is the total number of bytes of payload, including any
overflow
<li>A varint which is the integer key, a.k.a. "[rowid]"
<li>The initial portion of the payload that does not spill to overflow
pages.
<li>A 4-byte big-endian integer page number for the first page of the
overflow page list - omitted if all payload fits on the b-tree page.
</ul></p></dd>

<dt><p>Table B-Tree Interior Cell (header 0x05):</p></dt>
<dd><p><ul>
<li>A 4-byte big-endian page number which is the left child pointer.
<li>A varint which is the integer key
</ul></p></dd>

<dt><p>Index B-Tree Leaf Cell (header 0x0a):</p></dt>
<dd><p><ul>
<li>A varint which is the total number of bytes of key payload, including any
overflow
<li>The initial portion of the payload that does not spill to overflow
pages.
<li>A 4-byte big-endian integer page number for the first page of the
overflow page list - omitted if all payload fits on the b-tree page.
</ul></p></dd>

<dt><p>Index B-Tree Interior Cell (header 0x02):</p></dt>
<dd><p><ul>
<li>A 4-byte big-endianpage number which is the left child pointer.
<li>A varint which is the total number of bytes of key payload, including any
overflow
<li>The initial portion of the payload that does not spill to overflow
pages.
<li>A 4-byte big-endian integer page number for the first page of the
overflow page list - omitted if all payload fits on the b-tree page.
</ul></p></dd>
</dl></blockquote>

<p>The information above can be recast into a table format as follows:</p>

<tcl>hd_fragment cellformat {cell format summary}</tcl>
<center>
<i>B-tree Cell Format</i>
<table border=1 width="80%">
<tr><th rowspan=2>Datatype
    <th colspan=4>Appears in...
    <th rowspan=2>Description
<tr><th>Table Leaf (0x0d)
    <th>Table Interior (0x05)
    <th>Index Leaf (0x0a)
    <th>Index Interior (0x02)
<tr><td align=center valign=top>4-byte integer
    <td align=center valign=top>&nbsp;
    <td align=center valign=top>&#x2714;
    <td align=center valign=top>&nbsp;
    <td align=center valign=top>&#x2714;
    <td align=left>Page number of left child
<tr><td align=center valign=top>varint

Within an FTS expression a <b>string</b> may be specified in one of two ways:

<ul>
  <li> <p>By enclosing it in double quotes ("). Within a string, any embedded
       double quote characters may be escaped SQL-style - by adding a second
       double-quote character.


  <li> <p>As an FTS5 bareword that is not "AND", "OR" or "NOT" (case sensitive). 
       An FTS5 bareword is a string of one or more consecutive characters that
       are all either:
       

       <ul>
         <li> Non-ASCII range characters (i.e. unicode codepoints greater 
              than 127), or 
         <li> One of the 52 upper and lower case ASCII characters, or
         <li> One of the 10 decimal digit ASCII characters, or
         <li> The underscore character (unicode codepoint 96).
       </ul>


       Strings that include any other characters must be quoted.
</ul>

<p>
FTS queries are made up of <b>phrases</b>. A phrase is an ordered list of 
one or more tokens. A string is transformed into a phrase by passing it to
the FTS table tokenizer. Two phrases can be concatenated into a single 
large phrase using the "+" operator. For example, assuming the tokenizer

  }
}
</tcl>
</ul></td></tr></table>
<p>Notes:
<ol>
<li>Pragmas whose names are marked through in the list above
are deprecated.  They are not maintained.  They continue to exist
for historical compatibility only.
Do not use the deprecated pragmas in new applications.
Remove deprecated pragmas
from existing applications at your earliest opportunity.</blockquote>
<li>These pragmas are used for debugging SQLite and
are only available when SQLite is compiled using [SQLITE_DEBUG].
<li>These pragmas are used for testing SQLite and are not recommended
for use in application programs.</ol></p>