I see `VIRTUAL TABLE` like the following. I don't quite understand how it works. My understanding is that it does not hold the real data. The data are from other tables. But for this specific case how to figure out where the data of each field is from? ~~~ sqlite3 -separator $'\t' getsploit.db 'select * from sqlite_master where type="table";' table exploits exploits 0 CREATE VIRTUAL TABLE exploits USING FTS4(id text, title text, published DATE, description text, sourceData text, vhref text) table exploits_content exploits_content 2 CREATE TABLE 'exploits_content'(docid INTEGER PRIMARY KEY, 'c0id', 'c1title', 'c2published', 'c3description', 'c4sourceData', 'c5vhref') table exploits_segments exploits_segments 3 CREATE TABLE 'exploits_segments'(blockid INTEGER PRIMARY KEY, block BLOB) table exploits_segdir exploits_segdir 4 CREATE TABLE 'exploits_segdir'(level INTEGER,idx INTEGER,start_block INTEGER,leaves_end_block INTEGER,end_block INTEGER,root BLOB,PRIMARY KEY(level, idx)) table exploits_docsize exploits_docsize 6 CREATE TABLE 'exploits_docsize'(docid INTEGER PRIMARY KEY, size BLOB) table exploits_stat exploits_stat 7 CREATE TABLE 'exploits_stat'(id INTEGER PRIMARY KEY, value BLOB) ~~~ For FTS4, is it just to speed up the search? So the virtual table could be created by `CREATE VIRTUAL TABLE exploits (id text, title text, published DATE, description text, sourceData text, vhref text)`? The only drawback is the search speed is much slower but the results should be the same whether FTS4 is used or not? Thanks.