-- Copyright (C) 2012-2013  Internet Systems Consortium.

-- Permission to use, copy, modify, and distribute this software for any
-- purpose with or without fee is hereby granted, provided that the above
-- copyright notice and this permission notice appear in all copies.

-- THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SYSTEMS CONSORTIUM
-- DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL
-- IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL
-- INTERNET SYSTEMS CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT,
-- INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING
-- FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
-- NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
-- WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

-- This is the BIND 10 DHCP schema specification for PostgreSQL.

-- The schema is reasonably portable (with the exception of some field types
-- specification, which are PostgreSQL-specific).  Minor changes might be needed
-- for other databases.

-- To create the schema, either type the command:

-- psql -U <user> -W <password> <database> < dhcpdb_create.pgsql

-- ... at the command prompt, or log in to the PostgreSQL database and at the "postgres=#"
-- prompt, issue the command:

-- @dhcpdb_create.pgsql


-- Holds the IPv4 leases.
CREATE TABLE lease4 (
    address BIGINT PRIMARY KEY NOT NULL,        -- IPv4 address
    hwaddr BYTEA,                               -- Hardware address
    client_id BYTEA,                            -- Client ID
    valid_lifetime BIGINT,                      -- Length of the lease (seconds)
    expire TIMESTAMP WITH TIME ZONE,            -- Expiration time of the lease
    subnet_id BIGINT,                           -- Subnet identification
    fqdn_fwd BOOLEAN,                           -- Has forward DNS update been performed by a server
    fqdn_rev BOOLEAN,                           -- Has reverse DNS update been performed by a server
    hostname VARCHAR(255)                       -- The FQDN of the client
    );


-- Create search indexes for lease4 table
-- index by hwaddr and subnet_id
CREATE INDEX lease4_by_hwaddr_subnet_id ON lease4 (hwaddr, subnet_id);

-- index by client_id and subnet_id
CREATE INDEX lease4_by_client_id_subnet_id ON lease4 (client_id, subnet_id);

-- Holds the IPv6 leases.
-- N.B. The use of a VARCHAR for the address is temporary for development:
-- it will eventually be replaced by BINARY(16).
CREATE TABLE lease6 (
    address VARCHAR(39) PRIMARY KEY NOT NULL,   -- IPv6 address
    duid BYTEA,                                 -- DUID
    valid_lifetime BIGINT,                      -- Length of the lease (seconds)
    expire TIMESTAMP WITH TIME ZONE,            -- Expiration time of the lease
    subnet_id BIGINT,                           -- Subnet identification
    pref_lifetime BIGINT,                       -- Preferred lifetime
    lease_type SMALLINT,                        -- Lease type (see lease6_types
                                                --    table for possible values)
    iaid INT,                                   -- See Section 10 of RFC 3315
    prefix_len SMALLINT,                        -- For IA_PD only
    fqdn_fwd BOOLEAN,                           -- Has forward DNS update been performed by a server
    fqdn_rev BOOLEAN,                           -- Has reverse DNS update been performed by a server
    hostname VARCHAR(255)                       -- The FQDN of the client
    );

-- Create search indexes for lease4 table
-- index by iaid, subnet_id, and duid
CREATE INDEX lease6_by_iaid_subnet_id_duid ON lease6 (iaid, subnet_id, duid);

-- ... and a definition of lease6 types.  This table is a convenience for
-- users of the database - if they want to view the lease table and use the
-- type names, they can join this table with the lease6 table
CREATE TABLE lease6_types (
    lease_type SMALLINT PRIMARY KEY NOT NULL,   -- Lease type code.
    name VARCHAR(5)                             -- Name of the lease type
    );
START TRANSACTION;
INSERT INTO lease6_types VALUES (0, 'IA_NA');   -- Non-temporary v6 addresses
INSERT INTO lease6_types VALUES (1, 'IA_TA');   -- Temporary v6 addresses
INSERT INTO lease6_types VALUES (2, 'IA_PD');   -- Prefix delegations
COMMIT;

-- Finally, the version of the schema.  We start at 0.1 during development.
-- This table is only modified during schema upgrades.  For historical reasons
-- (related to the names of the columns in the BIND 10 DNS database file), the
-- first column is called "version" and not "major".

-- NOTE: this MUST be kept in step with src/lib/dhcpsrv/tests/schema_copy.h,
--       which defines the schema for the unit tests.  If you are updating
--       the version number, the schema has changed: please ensure that
--       schema_copy.h has been updated as well.
CREATE TABLE schema_version (
    version INT PRIMARY KEY NOT NULL,       -- Major version number
    minor INT                               -- Minor version number
    );
START TRANSACTION;
INSERT INTO schema_version VALUES (1, 0);
COMMIT;

-- Notes:

-- Indexes
-- =======
-- It is likely that additional indexes will be needed.  However, the
-- increase in lookup performance from these will come at the expense
-- of a decrease in performance during insert operations due to the need
-- to update the indexes.  For this reason, the need for additional indexes
-- will be determined by experiment during performance tests.

-- The most likely additional indexes will cover the following columns:

-- expire
-- To speed up the deletion of expired leases from the database.

-- hwaddr and client_id
-- For lease stability: if a client requests a new lease, try to find an
-- existing or recently expired lease for it so that it can keep using the
-- same IP address.

-- Field Sizes
-- ===========
-- If any of the VARxxx field sizes are altered, the lengths in the MySQL
-- backend source file (mysql_lease_mgr.cc) must be correspondingly changed.

-- Portability
-- ===========
-- Some columns contain binary data so are stored as BYTEA instead of
-- VARCHAR.  This may be non-portable between databases: in this case, the
-- definition should be changed to VARCHAR.