Migration

From Cayley 0.6.1 to 0.7.x

First you need to dump all the data from the database via v0.6.1:

./cayley-0.6 dump --db <backend> --dbpath <address> --dump_type pquads --dump ./data.pq.gz

or using config file:

./cayley-0.6 dump --config <config> --dump_type pquads --dump ./data.pq.gz

And load the data into new database via v0.7.x (pq file extension is important):

./cayley load --init -d <new-backend> -a <new-address> -i ./data.pq.gz

or using config file:

./cayley load --init -c <new-config> -i ./data.pq.gz

Dump via text format

An above guide uses Cayley-specific binary format to avoid encoding and parsing overhead and to compress output file better.

As an alternative, a standard nquads file format can be used to dump and load data (note nq extension):

./cayley-0.6 dump --config <config> --dump ./data.nq.gz
./cayley load --init -c <new-config> -i ./data.nq.gz

Bolt, LevelDB, MongoDB

Cayley v0.7.0 is still able to read and write databases of these types in old format. It can be accessed by changing backend name from bolt/leveldb/mongo to bolt1/leveldb1/mongo1. Thus, you can use guide for moving data between different backends for v0.7.x (see below).

Note: support for old versions will be dropped starting from v0.7.1.

SQL

Data format for SQL between v0.6.1 and v0.7.x has not changed significantly. Database can be upgraded by executing the following SQL statements:

ALTER TABLE quads DROP id;
ALTER TABLE nodes ADD refs INT DEFAULT 0 NOT NULL;
ALTER TABLE nodes ALTER COLUMN refs DROP DEFAULT;
UPDATE nodes SET refs = 
  (SELECT count(1) FROM quads WHERE subject_hash = nodes.hash) +
  (SELECT count(1) FROM quads WHERE predicate_hash = nodes.hash) +
  (SELECT count(1) FROM quads WHERE object_hash = nodes.hash) +
  (SELECT count(1) FROM quads WHERE label_hash = nodes.hash);

From different backend (Cayley 0.7+)

First you need to dump all the data from old backend (pq extension is important):

./cayley dump -d <backend> -a <address> -o ./data.pq.gz

or using config file:

./cayley dump -c <config> -o ./data.pq.gz

And load the data into a new backend and/or database:

./cayley load --init -d <new-backend> -a <new-address> -i ./data.pq.gz

or using config file:

./cayley load --init -c <new-config> -i ./data.pq.gz

Dump via text format

An above guide uses Cayley-specific binary format to avoid encoding and parsing overhead and to compress output file better.

As an alternative, a standard nquads file format can be used to dump and load data (note nq extension):

./cayley dump -c <config> -o ./data.nq.gz
./cayley load --init -c <new-config> -i ./data.nq.gz