Acoustid Index
==============

Acoustid Index is a "number search engine". It's similar to text search
engines, but instead of searching in documents that consist of words,
it searches in documents that consist of 32-bit integers.

It's a simple inverted index data structure that doesn't do any kind of
processing on the indexed documents. This is useful for searching in
Chromaprint[1] audio fingerprints, which are nothing more than 32-bit
integer arrays.

  [1] http://acoustid.org/chromaprint

Reindexing from the Acoustid database:

 $ echo "COPY (SELECT id, acoustid_extract_query(fingerprint) FROM fingerprint) TO stdout DELIMITER '|' " \
       | psql -U acoustid acoustid | ./fpi-import -d idx/ -c -o

 1. Stop importing
 2. UPDATE fingerprint_index_queue SET fingerprint_id = (SELECT max(id) FROM fingerprint);
 3. Index the database
 4. Start importing

Running the server:

$ ./fpi-server 
Listening on "127.0.0.1" port 6080 

Simple client session:

$ telnet 127.0.0.1 6080
Trying 127.0.0.1...
Connected to 127.0.0.1.
Escape character is '^]'.
begin
OK 
insert 1 368308215,364034037,397576085,397509509,393249669,389054869
OK 
insert 2 1574172159,1598222797,1564660173,1564656069,1564537317,1565584741
OK 
insert 3 1130316157,1096749341,1075786015,1075655999,1075656047,1079977343
OK 
commit
OK 
search 1130316157,397509509,393249669,389054869
OK 1:3 3:1
quit
OK
Connection closed by foreign host.