>     SELECT zonefile_write(<file>, <table> [, <parameters>]);

where &lt;file&gt; is the name of the file to create on disk, &lt;table&gt; 
is the name of the database table to read and optional argument 
&lt;parameters&gt; is a JSON object containing various attributes that
influence creation of the zonefile file. 

Currently the only &lt;parameters&gt; attribute supported is 
<i>maxAutoFrameSize</i> (default value 65536), which sets the maximum 




uncompressed frame size in bytes for automatically generated zonefile 
frames.

























For example, to create a zonefile named "test.zonefile" based on the
contents of database table "test_input" and with a maximum automatic
frame size of 4096 bytes:

>     SELECT zonefile_write('test.zonefile', 'test_input',
>       '{"maxAutoFrameSize":4096}'
................................................................................

>     CREATE VIRTUAL TABLE z1 USING zonefile;

This creates two virtual tables in the database schema. One read-only table
named "z1", with a schema equivalent to:

>     CREATE TABLE z1(  -- this whole table is read-only
>       k INTEGER PRIMARY KEY,
>       v BLOB,
>       fileid INTEGER,
>       frame INTEGER,
>       ofst INTEGER,
>       sz INTEGER
>     );

And a read-write table named "z1_files" with a schema like:

>     CREATE TABLE z1_files(
>       filename TEXT PRIMARY KEY,
>       ekey BLOB,         -- encryption key

>     SELECT zonefile_write(<file>, <table> [, <parameters>]);

where &lt;file&gt; is the name of the file to create on disk, &lt;table&gt; 
is the name of the database table to read and optional argument 
&lt;parameters&gt; is a JSON object containing various attributes that
influence creation of the zonefile file. 

Currently, the following &lt;parameters&gt; attributes are supported:


<table border=1>
<tr align=left><th>Attribute<th>Default<th>Interpretation
<tr valign=top><td>maxAutoFrameSize<td>65536
<td>The maximum uncompressed frame size in bytes for automatically generated
zonefile frames.

<tr valign=top><td>compressionTypeContent<td>"none"
<td>The compression type used to compress each frame in the zonefile. 
Valid values are "none" (no compression), "zstd", "zstd_global_dict",
"zlib", "brotli", "lz4" and "lz4hc". Not all compression methods are
supported by all builds. The compression method supported by a build
depends on the combination of SQLITE_HAVE_ZSTD, SQLITE_HAVE_ZLIB,
SQLITE_HAVE_BROTLI and SQLITE_HAVE_LZ4 pre-processor symbols defined
at build time.

<tr valign=top><td>compressionTypeIndexData<td>"none"
<td>The compression type used to compress the zonefile index structure.
All values that are valid for the <i>compressionTypeContent</i> parameter,
except for "zstd_global_dict", are also valid for this option.

<tr valign=top><td>encryptionType<td>"none"
<td>The encryption type to use. At present the only valid values are
"none" (no encryption) and "xor" (an insecure mock encryption method
useful for testing only).

<tr valign=top><td>encryptionKey<td>""
<td>The encryption key (a string) to use. The value of this option is
ignored if <i>encryptionType</i> is set to "none".
</table>

For example, to create a zonefile named "test.zonefile" based on the
contents of database table "test_input" and with a maximum automatic
frame size of 4096 bytes:

>     SELECT zonefile_write('test.zonefile', 'test_input',
>       '{"maxAutoFrameSize":4096}'
................................................................................

>     CREATE VIRTUAL TABLE z1 USING zonefile;

This creates two virtual tables in the database schema. One read-only table
named "z1", with a schema equivalent to:

>     CREATE TABLE z1(  -- this whole table is read-only
>       k INTEGER PRIMARY KEY,     -- key value
>       v BLOB,                    -- associated blob of data
>       file TEXT,                 -- file this key is read from 


>       sz INTEGER                 -- size of blob of data in bytes
>     );

And a read-write table named "z1_files" with a schema like:

>     CREATE TABLE z1_files(
>       filename TEXT PRIMARY KEY,
>       ekey BLOB,         -- encryption key