USING SQL FOR LOOKUPS, LOG/REPORTING AND QUARANTINE
===================================================

This text only describes SQL specifics for a MySQL database
and provides a schema.

For general aspects of lookups, please see README.lookups.
For general SQL notes and further examples please see README.sql.
For PostgreSQL-specific notes and schema please see README.sql-pg
(which in most respects also applies to a SQLite database).

SERIAL can be used instead of INT UNSIGNED NOT NULL AUTO_INCREMENT
with databases which do not recognize AUTO_INCREMENT;
The attribute SERIAL was introduced with MySQL 4.1.0, but it
implicitly creates an additional UNIQUE index, which is redundant.

Instead of declaring a time_iso field in table msgs as a string:
  time_iso char(16) NOT NULL,
one may want to declare is as:
  time_iso TIMESTAMP NOT NULL DEFAULT 0,
in which case $timestamp_fmt_mysql *MUST* be set to 1 in amavisd.conf
to avoid MySQL inability to accept ISO 8601 timestamps with zone Z
and ISO date/time delimiter T; failing to set $timestamp_fmt_mysql
makes MySQL store zero time on INSERT and write current local time
on UPDATE if auto-update is allowed, which is different from the
intended mail timestamp (localtime vs. UTC, off by seconds)

Field quarantine.mail_text should be of data type 'blob' and not 'text'
as suggested in earlier documentation; this is to prevent it from being
unjustifiably associated with a character set, and to be able to
store any byte value; to convert existing field from type 'text'
to type 'blob' the following clause may be used:
  ALTER TABLE quarantine CHANGE mail_text mail_text blob;

Although MySQL is not particularly picky in checking and enforcing data
types, it is appropriate to declare fields users.email, mailaddr.email,
and maddr.email as byte strings with no associated character set (which is
what these fields are, according to RFC 2821) instead of CHAR or VARCHAR.
The following clauses convert pre-2.6.0 tables into the now recommended form:
  ALTER TABLE users      CHANGE email email varbinary(255);
  ALTER TABLE mailaddr   CHANGE email email varbinary(255);
  ALTER TABLE maddr      CHANGE email email varbinary(255);
If VARBINARY data type is chosen for these three fields, the setting
$sql_allow_8bit_address should be set to true to let the amavisd program
use the appropriate data type in SQL commands:
  $sql_allow_8bit_address = 1; # maddr.email: VARCHAR (0), VARBINARY/BYTEA (1)

Similarly, semantics of some other fields is strings of octets too, with
no associated character set (which is a characteristic of char and varchar
data types), so the following alternations to pre-2.6.2 schema may be
beneficial to prevent SQL server from checking validity of octets data
against non-applicable arbitrary character set constraints:
  ALTER table msgs       CHANGE mail_id mail_id varbinary(16);
  ALTER table msgs       CHANGE secret_id secret_id varbinary(16);
  ALTER table msgs       CHANGE quar_loc quar_loc varbinary(255);
  ALTER table msgrcpt    CHANGE mail_id mail_id varbinary(16);
  ALTER table quarantine CHANGE mail_id mail_id varbinary(16);
and for good measure:
  ALTER table msgrcpt    CHANGE rid rid bigint unsigned;
  ALTER table msgs       CHANGE sid sid bigint unsigned;

Starting with amavisd-new-2.7.0, three fields need to be added
to table msgrcpt and one to table msgs:
  ALTER TABLE msgrcpt ADD rseqnum     integer  DEFAULT 0   NOT NULL;
  ALTER TABLE msgrcpt ADD content     char(1)  DEFAULT ' ' NOT NULL;
  ALTER TABLE msgrcpt ADD is_local    char(1)  DEFAULT ' ' NOT NULL;
  ALTER TABLE msgs    ADD originating char(1)  DEFAULT ' ' NOT NULL;

If you need to create a primary key on table msgrcpt for some reason
(clustering?), try something like:
  UPDATE msgrcpt SET rseqnum=1+floor(999999999*rand()) WHERE rseqnum=0;
  ALTER TABLE msgrcpt ADD PRIMARY KEY (partition_tag,mail_id,rseqnum);


-- local users
CREATE TABLE users (
  id         int unsigned NOT NULL AUTO_INCREMENT PRIMARY KEY,  -- unique id
  priority   integer      NOT NULL DEFAULT '7',  -- sort field, 0 is low prior.
  policy_id  integer unsigned NOT NULL DEFAULT '1',  -- JOINs with policy.id
  email      varbinary(255) NOT NULL UNIQUE,
  fullname   varchar(255) DEFAULT NULL    -- not used by amavisd-new
  -- local   char(1)      -- Y/N  (optional field, see note further down)
);

-- any e-mail address (non- rfc2822-quoted), external or local,
-- used as senders in wblist
CREATE TABLE mailaddr (
  id         int unsigned NOT NULL AUTO_INCREMENT PRIMARY KEY,
  priority   integer      NOT NULL DEFAULT '7',  -- 0 is low priority
  email      varbinary(255) NOT NULL UNIQUE
);

-- per-recipient whitelist and/or blacklist,
-- puts sender and recipient in relation wb  (white or blacklisted sender)
CREATE TABLE wblist (
  rid        integer unsigned NOT NULL,  -- recipient: users.id
  sid        integer unsigned NOT NULL,  -- sender: mailaddr.id
  wb         varchar(10)  NOT NULL,  -- W or Y / B or N / space=neutral / score
  PRIMARY KEY (rid,sid)
);

CREATE TABLE policy (
  id  int unsigned NOT NULL AUTO_INCREMENT PRIMARY KEY,
                                    -- 'id' this is the _only_ required field
  policy_name      varchar(32),     -- not used by amavisd-new, a comment

  virus_lover           char(1) default NULL,     -- Y/N
  spam_lover            char(1) default NULL,     -- Y/N
  unchecked_lover       char(1) default NULL,     -- Y/N
  banned_files_lover    char(1) default NULL,     -- Y/N
  bad_header_lover      char(1) default NULL,     -- Y/N

  bypass_virus_checks   char(1) default NULL,     -- Y/N
  bypass_spam_checks    char(1) default NULL,     -- Y/N
  bypass_banned_checks  char(1) default NULL,     -- Y/N
  bypass_header_checks  char(1) default NULL,     -- Y/N

  virus_quarantine_to      varchar(64) default NULL,
  spam_quarantine_to       varchar(64) default NULL,
  banned_quarantine_to     varchar(64) default NULL,
  unchecked_quarantine_to  varchar(64) default NULL,
  bad_header_quarantine_to varchar(64) default NULL,
  clean_quarantine_to      varchar(64) default NULL,
  archive_quarantine_to    varchar(64) default NULL,

  spam_tag_level  float default NULL, -- higher score inserts spam info headers
  spam_tag2_level float default NULL, -- inserts 'declared spam' header fields
  spam_tag3_level float default NULL, -- inserts 'blatant spam' header fields
  spam_kill_level float default NULL, -- higher score triggers evasive actions
                                      -- e.g. reject/drop, quarantine, ...
                                     -- (subject to final_spam_destiny setting)
  spam_dsn_cutoff_level        float default NULL,
  spam_quarantine_cutoff_level float default NULL,

  addr_extension_virus      varchar(64) default NULL,
  addr_extension_spam       varchar(64) default NULL,
  addr_extension_banned     varchar(64) default NULL,
  addr_extension_bad_header varchar(64) default NULL,

  warnvirusrecip      char(1)     default NULL, -- Y/N
  warnbannedrecip     char(1)     default NULL, -- Y/N
  warnbadhrecip       char(1)     default NULL, -- Y/N
  newvirus_admin      varchar(64) default NULL,
  virus_admin         varchar(64) default NULL,
  banned_admin        varchar(64) default NULL,
  bad_header_admin    varchar(64) default NULL,
  spam_admin          varchar(64) default NULL,
  spam_subject_tag    varchar(64) default NULL,
  spam_subject_tag2   varchar(64) default NULL,
  spam_subject_tag3   varchar(64) default NULL,
  message_size_limit  integer     default NULL, -- max size in bytes, 0 disable
  banned_rulenames    varchar(64) default NULL, -- comma-separated list of ...
        -- names mapped through %banned_rules to actual banned_filename tables
  disclaimer_options  varchar(64) default NULL,
  forward_method      varchar(64) default NULL,
  sa_userconf         varchar(64) default NULL,
  sa_username         varchar(64) default NULL
);


-- R/W part of the dataset (optional)
--   May reside in the same or in a separate database as lookups database;
--   REQUIRES SUPPORT FOR TRANSACTIONS; specified in @storage_sql_dsn
--
--   MySQL note ( http://dev.mysql.com/doc/mysql/en/storage-engines.html ):
--     ENGINE is the preferred term, but cannot be used before MySQL 4.0.18.
--     TYPE is available beginning with MySQL 3.23.0, the first version of
--     MySQL for which multiple storage engines were available. If you omit
--     the ENGINE or TYPE option, the default storage engine is used.
--     By default this is MyISAM.
--
--  Please create additional indexes on keys when needed, or drop suggested
--  ones as appropriate to optimize queries needed by a management application.
--  See your database documentation for further optimization hints. With MySQL
--  see Chapter 15 of the reference manual. For example the chapter 15.17 says:
--  InnoDB does not keep an internal count of rows in a table. To process a
--  SELECT COUNT(*) FROM T statement, InnoDB must scan an index of the table,
--  which takes some time if the index is not entirely in the buffer pool.
--
--  Wayne Smith adds: When using MySQL with InnoDB one might want to
--  increase buffer size for both pool and log, and might also want
--  to change flush settings for a little better performance. Example:
--    innodb_buffer_pool_size = 384M
--    innodb_log_buffer_size = 8M
--    innodb_flush_log_at_trx_commit = 0
--  The big performance increase is the first two, the third just helps with
--  lowering disk activity. Consider also adjusting the key_buffer_size.

-- provide unique id for each e-mail address, avoids storing copies
CREATE TABLE maddr (
  partition_tag integer      DEFAULT 0, -- see $partition_tag
  id         bigint unsigned NOT NULL AUTO_INCREMENT PRIMARY KEY,
  email      varbinary(255)  NOT NULL,  -- full mail address
  domain     varchar(255)    NOT NULL,  -- only domain part of the email address
                                        -- with subdomain fields in reverse
  CONSTRAINT part_email UNIQUE (partition_tag,email)
) ENGINE=InnoDB;

-- information pertaining to each processed message as a whole;
-- NOTE: records with NULL msgs.content should be ignored by utilities,
--   as such records correspond to messages just being processes, or were lost
-- NOTE: instead of a character field time_iso, one might prefer:
--   time_iso TIMESTAMP NOT NULL DEFAULT 0,
--   but the following MUST then be set in amavisd.conf: $timestamp_fmt_mysql=1
CREATE TABLE msgs (
  partition_tag integer     DEFAULT 0,   -- see $partition_tag
  mail_id     varbinary(16) NOT NULL,    -- long-term unique mail id, dflt 12 ch
  secret_id   varbinary(16) DEFAULT '',  -- authorizes release of mail_id, 12 ch
  am_id       varchar(20)   NOT NULL,    -- id used in the log
  time_num    integer unsigned NOT NULL, -- rx_time: seconds since Unix epoch
  time_iso    char(16)      NOT NULL,    -- rx_time: ISO8601 UTC ascii time
  sid         bigint unsigned NOT NULL,  -- sender: maddr.id
  policy      varchar(255)  DEFAULT '',  -- policy bank path (like macro %p)
  client_addr varchar(255)  DEFAULT '',  -- SMTP client IP address (IPv4 or v6)
  size        integer unsigned NOT NULL, -- message size in bytes
  originating char(1) DEFAULT ' ' NOT NULL,  -- sender from inside or auth'd
  content     char(1),                   -- content type: V/B/U/S/Y/M/H/O/T/C
    -- virus/banned/unchecked/spam(kill)/spammy(tag2)/
    -- /bad-mime/bad-header/oversized/mta-err/clean
    -- is NULL on partially processed mail
    -- (prior to 2.7.0 the CC_SPAMMY was logged as 's', now 'Y' is used;
    -- to avoid a need for case-insenstivity in queries)
  quar_type  char(1),                   -- quarantined as: ' '/F/Z/B/Q/M/L
                                        --  none/file/zipfile/bsmtp/sql/
                                        --  /mailbox(smtp)/mailbox(lmtp)
  quar_loc   varbinary(255) DEFAULT '', -- quarantine location (e.g. file)
  dsn_sent   char(1),                   -- was DSN sent? Y/N/q (q=quenched)
  spam_level float,                     -- SA spam level (no boosts)
  message_id varchar(255)  DEFAULT '',  -- mail Message-ID header field
  from_addr  varchar(255)  CHARACTER SET utf8mb4 COLLATE utf8mb4_bin  DEFAULT '',
                                        -- mail From header field,    UTF8
  subject    varchar(255)  CHARACTER SET utf8mb4 COLLATE utf8mb4_bin  DEFAULT '',
                                        -- mail Subject header field, UTF8
  host       varchar(255)  NOT NULL,    -- hostname where amavisd is running
  PRIMARY KEY (partition_tag,mail_id)
-- FOREIGN KEY (sid) REFERENCES maddr(id) ON DELETE RESTRICT
) ENGINE=InnoDB;
CREATE INDEX msgs_idx_sid      ON msgs (sid);
CREATE INDEX msgs_idx_mess_id  ON msgs (message_id); -- useful with pen pals
CREATE INDEX msgs_idx_time_num ON msgs (time_num);
-- alternatively when purging based on time_iso (instead of msgs_idx_time_num):
--   CREATE INDEX msgs_idx_time_iso ON msgs (time_iso);
-- When using FOREIGN KEY contraints, InnoDB requires index on a field
-- (an the field must be the first field in the index).  Hence create it:
--   CREATE INDEX msgs_idx_mail_id  ON msgs (mail_id);

-- per-recipient information related to each processed message;
-- NOTE: records in msgrcpt without corresponding msgs.mail_id record are
--  orphaned and should be ignored and eventually deleted by external utilities
CREATE TABLE msgrcpt (
  partition_tag integer    DEFAULT 0,    -- see $partition_tag
  mail_id    varbinary(16) NOT NULL,     -- (must allow duplicates)
  rseqnum    integer  DEFAULT 0   NOT NULL, -- recip's enumeration within msg
  rid        bigint unsigned NOT NULL,   -- recipient: maddr.id (dupl. allowed)
  is_local   char(1)  DEFAULT ' ' NOT NULL, -- recip is: Y=local, N=foreign
  content    char(1)  DEFAULT ' ' NOT NULL, -- content type V/B/U/S/Y/M/H/O/T/C
  ds         char(1)  NOT NULL,          -- delivery status: P/R/B/D/T
                                         -- pass/reject/bounce/discard/tempfail
  rs         char(1)  NOT NULL,          -- release status: initialized to ' '
  bl         char(1)  DEFAULT ' ',       -- sender blacklisted by this recip
  wl         char(1)  DEFAULT ' ',       -- sender whitelisted by this recip
  bspam_level float,                     -- per-recipient (total) spam level
  smtp_resp  varchar(255)  DEFAULT '',   -- SMTP response given to MTA
  PRIMARY KEY (partition_tag,mail_id,rseqnum)
-- FOREIGN KEY (rid)     REFERENCES maddr(id)     ON DELETE RESTRICT,
-- FOREIGN KEY (mail_id) REFERENCES msgs(mail_id) ON DELETE CASCADE
) ENGINE=InnoDB;
CREATE INDEX msgrcpt_idx_mail_id  ON msgrcpt (mail_id);
CREATE INDEX msgrcpt_idx_rid      ON msgrcpt (rid);

-- mail quarantine in SQL, enabled by $*_quarantine_method='sql:'
-- NOTE: records in quarantine without corresponding msgs.mail_id record are
--  orphaned and should be ignored and eventually deleted by external utilities
CREATE TABLE quarantine (
  partition_tag integer    DEFAULT 0,    -- see $partition_tag
  mail_id    varbinary(16) NOT NULL,     -- long-term unique mail id
  chunk_ind  integer unsigned NOT NULL,  -- chunk number, starting with 1
  mail_text  blob          NOT NULL,     -- store mail as chunks of octets
  PRIMARY KEY (partition_tag,mail_id,chunk_ind)
-- FOREIGN KEY (mail_id) REFERENCES msgs(mail_id) ON DELETE CASCADE
) ENGINE=InnoDB;

-- field msgrcpt.rs is primarily intended for use by quarantine management
-- software; the value assigned by amavisd is a space;
-- a short _preliminary_ list of possible values:
--   'V' => viewed (marked as read)
--   'R' => released (delivered) to this recipient
--   'p' => pending (a status given to messages when the admin received the
--                   request but not yet released; targeted to banned parts)
--   'D' => marked for deletion; a cleanup script may delete it


-- =====================
-- Example data follows:
-- =====================
INSERT INTO users VALUES ( 1, 9, 5, 'user1+foo@y.example.com','Name1 Surname1', 'Y');
INSERT INTO users VALUES ( 2, 7, 5, 'user1@y.example.com', 'Name1 Surname1', 'Y');
INSERT INTO users VALUES ( 3, 7, 2, 'user2@y.example.com', 'Name2 Surname2', 'Y');
INSERT INTO users VALUES ( 4, 7, 7, 'user3@z.example.com', 'Name3 Surname3', 'Y');
INSERT INTO users VALUES ( 5, 7, 7, 'user4@example.com',   'Name4 Surname4', 'Y');
INSERT INTO users VALUES ( 6, 7, 1, 'user5@example.com',   'Name5 Surname5', 'Y');
INSERT INTO users VALUES ( 7, 5, 0, '@sub1.example.com', NULL, 'Y');
INSERT INTO users VALUES ( 8, 5, 7, '@sub2.example.com', NULL, 'Y');
INSERT INTO users VALUES ( 9, 5, 5, '@example.com',      NULL, 'Y');
INSERT INTO users VALUES (10, 3, 8, 'userA', 'NameA SurnameA anywhere', 'Y');
INSERT INTO users VALUES (11, 3, 9, 'userB', 'NameB SurnameB', 'Y');
INSERT INTO users VALUES (12, 3,10, 'userC', 'NameC SurnameC', 'Y');
INSERT INTO users VALUES (13, 3,11, 'userD', 'NameD SurnameD', 'Y');
INSERT INTO users VALUES (14, 3, 0, '@sub1.example.net', NULL, 'Y');
INSERT INTO users VALUES (15, 3, 7, '@sub2.example.net', NULL, 'Y');
INSERT INTO users VALUES (16, 3, 5, '@example.net',      NULL, 'Y');
INSERT INTO users VALUES (17, 7, 5, 'u1@example.org',    'u1', 'Y');
INSERT INTO users VALUES (18, 7, 6, 'u2@example.org',    'u2', 'Y');
INSERT INTO users VALUES (19, 7, 3, 'u3@example.org',    'u3', 'Y');

-- INSERT INTO users VALUES (20, 0, 5, '@.',             NULL, 'N');  -- catchall

INSERT INTO policy (id, policy_name,
  virus_lover, spam_lover, banned_files_lover, bad_header_lover,
  bypass_virus_checks, bypass_spam_checks,
  bypass_banned_checks, bypass_header_checks, spam_modifies_subj,
  spam_tag_level, spam_tag2_level, spam_kill_level) VALUES
  (1, 'Non-paying',    'N','N','N','N', 'Y','Y','Y','N', 'Y', 3.0,   7, 10),
  (2, 'Uncensored',    'Y','Y','Y','Y', 'N','N','N','N', 'N', 3.0, 999, 999),
  (3, 'Wants all spam','N','Y','N','N', 'N','N','N','N', 'Y', 3.0, 999, 999),
  (4, 'Wants viruses', 'Y','N','Y','Y', 'N','N','N','N', 'Y', 3.0, 6.9, 6.9),
  (5, 'Normal',        'N','N','N','N', 'N','N','N','N', 'Y', 3.0, 6.9, 6.9),
  (6, 'Trigger happy', 'N','N','N','N', 'N','N','N','N', 'Y', 3.0,   5, 5),
  (7, 'Permissive',    'N','N','N','Y', 'N','N','N','N', 'Y', 3.0,  10, 20),
  (8, '6.5/7.8',       'N','N','N','N', 'N','N','N','N', 'N', 3.0, 6.5, 7.8),
  (9, 'userB',         'N','N','N','Y', 'N','N','N','N', 'Y', 3.0, 6.3, 6.3),
  (10,'userC',         'N','N','N','N', 'N','N','N','N', 'N', 3.0, 6.0, 6.0),
  (11,'userD',         'Y','N','Y','Y', 'N','N','N','N', 'N', 3.0,   7, 7);

-- sender envelope addresses needed for white/blacklisting
INSERT INTO mailaddr VALUES (1, 5, '@example.com');
INSERT INTO mailaddr VALUES (2, 9, 'owner-postfix-users@postfix.org');
INSERT INTO mailaddr VALUES (3, 9, 'amavis-user-admin@lists.sourceforge.net');
INSERT INTO mailaddr VALUES (4, 9, 'makemoney@example.com');
INSERT INTO mailaddr VALUES (5, 5, '@example.net');
INSERT INTO mailaddr VALUES (6, 9, 'spamassassin-talk-admin@lists.sourceforge.net');
INSERT INTO mailaddr VALUES (7, 9, 'spambayes-bounces@python.org');

-- whitelist for user 14, i.e. default for recipients in domain sub1.example.net
INSERT INTO wblist VALUES (14, 1, 'W');
INSERT INTO wblist VALUES (14, 3, 'W');

-- whitelist and blacklist for user 17, i.e. u1@example.org
INSERT INTO wblist VALUES (17, 2, 'W');
INSERT INTO wblist VALUES (17, 3, 'W');
INSERT INTO wblist VALUES (17, 6, 'W');
INSERT INTO wblist VALUES (17, 7, 'W');
INSERT INTO wblist VALUES (17, 5, 'B');
INSERT INTO wblist VALUES (17, 4, 'B');

-- $sql_select_policy setting in amavisd.conf tells amavisd
-- how to fetch per-recipient policy settings.
-- See comments there. Example:
--
-- SELECT *,users.id FROM users,policy
--   WHERE (users.policy_id=policy.id) AND (users.email IN (%k))
--   ORDER BY users.priority DESC;
--
-- $sql_select_white_black_list in amavisd.conf tells amavisd
-- how to check sender in per-recipient whitelist/blacklist.
-- See comments there. Example:
--
-- SELECT wb FROM wblist,mailaddr
--   WHERE (wblist.rid=?) AND (wblist.sid=mailaddr.id) AND (mailaddr.email IN (%k))
--   ORDER BY mailaddr.priority DESC;



-- NOTE: the SELECT, INSERT and UPDATE clauses as used by the amavisd-new
-- program are configurable through %sql_clause; see amavisd.conf-default



Some examples of a query:

-- mail from last two minutes:
SELECT
  UNIX_TIMESTAMP()-msgs.time_num AS age, SUBSTRING(policy,1,2) as pb,
  msgrcpt.content AS c, dsn_sent as dsn, ds, bspam_level AS level, size,
  SUBSTRING(sender.email,1,18) AS s,
  SUBSTRING(recip.email,1,18)  AS r,
  SUBSTRING(msgs.subject,1,10) AS subj
  FROM msgs LEFT JOIN msgrcpt         ON msgs.mail_id=msgrcpt.mail_id
            LEFT JOIN maddr AS sender ON msgs.sid=sender.id
            LEFT JOIN maddr AS recip  ON msgrcpt.rid=recip.id
  WHERE msgrcpt.content IS NOT NULL AND UNIX_TIMESTAMP()-msgs.time_num < 120
  ORDER BY msgs.time_num DESC;

-- clean messages ordered by count, grouped by domain:
SELECT count(*) as cnt, avg(bspam_level), sender.domain
  FROM msgs
  LEFT JOIN msgrcpt ON msgs.mail_id=msgrcpt.mail_id
  LEFT JOIN maddr AS sender ON msgs.sid=sender.id
  LEFT JOIN maddr AS recip ON msgrcpt.rid=recip.id
  WHERE msgrcpt.content='C'
  GROUP BY sender.domain ORDER BY cnt DESC LIMIT 50;

-- top spamy domains with >10 messages, sorted by spam average,
-- grouped by domain:
SELECT count(*) as cnt, avg(bspam_level) as spam_avg, sender.domain
  FROM msgs
  LEFT JOIN msgrcpt ON msgs.mail_id=msgrcpt.mail_id
  LEFT JOIN maddr AS sender ON msgs.sid=sender.id
  LEFT JOIN maddr AS recip ON msgrcpt.rid=recip.id
  WHERE bspam_level IS NOT NULL
  GROUP BY sender.domain HAVING count(*) > 10
  ORDER BY spam_avg DESC LIMIT 50;

-- sender domains with >100 messages, sorted on sender.domain:
SELECT count(*) as cnt, avg(bspam_level) as spam_avg, sender.domain
  FROM msgs
  LEFT JOIN msgrcpt ON msgs.mail_id=msgrcpt.mail_id
  LEFT JOIN maddr AS sender ON msgs.sid=sender.id
  LEFT JOIN maddr AS recip ON msgrcpt.rid=recip.id
  GROUP BY sender.domain HAVING count(*) > 100
  ORDER BY sender.domain DESC LIMIT 100;




Upgrading from pre 2.4.0 amavisd-new SQL schema to the 2.4.0 schema requires
adding column 'quar_loc' to table msgs, and creating FOREIGN KEY constraint
to facilitate deletion of expired records.

The following clauses should be executed for upgrading pre-2.4.0 amavisd-new
SQL schema to the 2.4.0 schema. Creating a FOREIGN KEY ... ON DELETE CASCADE
constraint may (or may not) facilitate deletion of expired records.

-- mandatory change:
  ALTER TABLE msgs ADD quar_loc varchar(255) DEFAULT '';

-- optional, avoids need to purge tables msgrcpt and quarantine explicitly:
  ALTER TABLE quarantine
    ADD FOREIGN KEY (mail_id) REFERENCES msgs(mail_id) ON DELETE CASCADE;
  ALTER TABLE msgrcpt
    ADD FOREIGN KEY (mail_id) REFERENCES msgs(mail_id) ON DELETE CASCADE;

-- the following two ALTERs are not essential; if data type of maddr.id is
-- incompatible with msgs.sid and msgs.rid (e.g. BIGINT vs. INT) and MySQL
-- complains, don't bother to apply the constraint:
  ALTER TABLE msgs
    ADD FOREIGN KEY (sid) REFERENCES maddr(id) ON DELETE RESTRICT;
  ALTER TABLE msgrcpt
    ADD FOREIGN KEY (rid) REFERENCES maddr(id) ON DELETE RESTRICT;


EXAMPLE of a log/report/quarantine database housekeeping
========================================================

Using a changing partition_tag, perhaps by using an ISO 8601 week number
(value 1 to 53) as a partition_tag:

  $partition_tag =
    sub { my($msginfo)=@_; sprintf("%02d",iso8601_week($msginfo->rx_time)) };

allows for probably the fastest method of purging old records, e.g.:

DELETE FROM msgs       WHERE partition_tag >= 13 AND partition_tag <= 23;
DELETE FROM msgrcpt    WHERE partition_tag >= 13 AND partition_tag <= 23;
DELETE FROM quarantine WHERE partition_tag >= 13 AND partition_tag <= 23;
DELETE FROM maddr      WHERE partition_tag >= 13 AND partition_tag <= 23;

  Note: using native SQL table partitioning as offered by MySQL, the above
  may be even faster by dropping entire partitions. Not documented here.


Alternatively, purge records from table msgs by their creation time:

DELETE FROM msgs WHERE time_num < UNIX_TIMESTAMP() - 21*24*3600;
DELETE FROM msgs WHERE time_num < UNIX_TIMESTAMP() - 3600 AND content IS NULL;

Optionally certain content types may be given shorter lifetime:

DELETE FROM msgs WHERE time_num < UNIX_TIMESTAMP() - 7*24*3600
  AND (content='V' OR (content='S' AND spam_level > 20));

( or equivalently, if a data type of msgs.time_iso is TIMESTAMPS
  and in amavisd.conf the $timestamp_fmt_mysql is set to true:
  DELETE FROM msgs WHERE time_iso < UTC_TIMESTAMP() - INTERVAL 21 day;
  DELETE FROM msgs WHERE time_iso < UTC_TIMESTAMP() - INTERVAL 1 hour
    AND content IS NULL;
  DELETE FROM msgs WHERE time_iso < UTC_TIMESTAMP() - INTERVAL 7 day
    AND (content='V' OR (content='S' AND spam_level > 20));
)


Then delete unreferenced records from tables msgrcpt and quarantine,
unless they were already automatically deleted while purging the msgs
table and FOREIGN KEY ... ON DELETE CASCADE is in place:

DELETE FROM msgrcpt
  WHERE NOT EXISTS (SELECT 1 FROM msgs WHERE mail_id=msgrcpt.mail_id);

DELETE FROM quarantine
  WHERE NOT EXISTS (SELECT 1 FROM msgs WHERE mail_id=quarantine.mail_id);

( or equivalently:
  DELETE msgrcpt FROM msgrcpt LEFT JOIN msgs USING(mail_id)
    WHERE msgs.mail_id IS NULL;
  DELETE quarantine FROM quarantine LEFT JOIN msgs USING(mail_id)
    WHERE msgs.mail_id IS NULL;
)


Finally delete unreferenced records from table maddr:

DELETE FROM maddr
  WHERE NOT EXISTS (SELECT 1 FROM msgs    WHERE sid=id)
    AND NOT EXISTS (SELECT 1 FROM msgrcpt WHERE rid=id);



SOME FURTHER THOUGHTS on a log/report/quarantine database housekeeping
======================================================================

Discarding indexes makes deletion faster; if we expect a large proportion
of records to be deleted it may be quicker to discard index, do deletions,
and re-create index; for daily maintenance this does not pay off

DROP INDEX msgs_idx_sid         ON msgs;
DROP INDEX msgrcpt_idx_rid      ON msgrcpt;
DROP INDEX msgrcpt_idx_mail_id  ON msgrcpt;

Re-create indexes (if they were removed in the first step):

CREATE INDEX msgs_idx_sid        ON msgs    (sid);
CREATE INDEX msgrcpt_idx_rid     ON msgrcpt (rid);
CREATE INDEX msgrcpt_idx_mail_id ON msgrcpt (mail_id);

Optionally, optimize tables once in a while:

OPTIMIZE TABLE msgs, msgrcpt, quarantine, maddr;
