NAME

       Mail::SpamAssassin::BayesStore::PgSQL - PostgreSQL Specific Bayesian Storage Module
       Implementation

DESCRIPTION

       This module implements a PostgreSQL specific bayesian storage module.

       It subclasses Mail::SpamAssassin::BayesStore::SQL and overrides any methods which makes
       SQL calls involving the token column.  Since PostgreSQL uses BYTEA for the token column
       type you must make sure that the DBD driver does the proper quoting.  You can accomplish
       this by binding the token column to a specific type.

       In versions 8.3 and up, synchronous_commit is disabled for faster performance.  Data is
       not guaranteed to be stored until (3 * wal_writer_delay) (default: 0.6s) after it is
       written. This tradeoff works for Bayes because we care about aggregate data and a small
       period of time can be lost without sacrificing accuracy.

METHODS

   token_expiration
       public instance (Integer, Integer,
                        Integer, Integer) token_expiration(\% $opts,
                                                           Integer $newdelta,
                                                           @ @vars)

       Description: This method performs the database specific expiration of tokens based on the
       passed in $newdelta and @vars.

   seen_put
       public (Boolean) seen_put (string $msgid, char $flag)

       Description: This method records $msgid as the type given by $flag.  $flag is one of two
       values 's' for spam and 'h' for ham.

   seen_delete
       public instance (Boolean) seen_delete (string $msgid)

       Description: This method removes $msgid from the database.

   set_last_expire
       public instance (Boolean) set_last_expire (Integer $time)

       Description: This method sets the last expire time.

   set_running_expire_tok
       public instance (String $time) set_running_expire_tok ()

       Description: This method sets the time that an expire starts running.

   remove_running_expire_tok
       public instance (Boolean) remove_running_expire_tok ()

       Description: This method removes the row in the database that indicates that and expire is
       currently running.

   tok_get
       public instance (Integer, Integer, Integer) tok_get (String $token)

       Description: This method retrieves a specificed token ($token) from the database and
       returns it's spam_count, ham_count and last access time.

   tok_get_all
       public instance (\@) tok_get (@ $tokens)

       Description: This method retrieves the specified tokens ($tokens) from storage and returns
       an array ref of arrays spam count, ham acount and last access time.

   nspam_nham_change
       public instance (Boolean) nspam_nham_change (Integer $num_spam,
                                                    Integer $num_ham)

       Description: This method updates the number of spam and the number of ham in the database.

   tok_touch
       public instance (Boolean) tok_touch (String $token,
                                            String $atime)

       Description: This method updates the given tokens ($token) atime.

       The assumption is that the token already exists in the database.

   tok_touch_all
       public instance (Boolean) tok_touch (\@ $tokens
                                            String $atime)

       Description: This method does a mass update of the given list of tokens $tokens, if the
       existing token atime is < $atime.

       The assumption is that the tokens already exist in the database.

       We should never be touching more than N_SIGNIFICANT_TOKENS, so we can make some
       assumptions about how to handle the data (ie no need to batch like we do in tok_get_all)

   cleanup
       public instance (Boolean) cleanup ()

       Description: This method perfoms any cleanup necessary before moving onto the next
       operation.

   clear_database
       public instance (Boolean) clear_database ()

       Description: This method deletes all records for a particular user.

       Callers should be aware that any errors returned by this method could causes the database
       to be inconsistent for the given user.

Private Methods

   _connect_db
       private instance (Boolean) _connect_db ()

       Description: This method connects to the SQL database.

   _put_token
       private instance (Boolean) _put_token (string $token,
                                              integer $spam_count,
                                              integer $ham_count,
       string $atime)

       Description: This method performs the work of either inserting or updating a token in the
       database.

   _put_tokens
       private instance (Boolean) _put_tokens (\% $token,
                                               integer $spam_count,
                                               integer $ham_count,
       string $atime)

       Description: This method performs the work of either inserting or updating tokens in the
       database.

   _token_select_string
       private instance (String) _token_select_string

       Description: This method returns the string to be used in SELECT statements to represent
       the token column.