Merge "Remove left-over use of wfMsg" into Wikidata
[lhc/web/wiklou.git] / includes / installer / PostgresInstaller.php
index 1e55737..3ac2b3a 100644 (file)
@@ -2,6 +2,21 @@
 /**
  * PostgreSQL-specific installer.
  *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ * http://www.gnu.org/copyleft/gpl.html
+ *
  * @file
  * @ingroup Deployment
  */
@@ -23,8 +38,14 @@ class PostgresInstaller extends DatabaseInstaller {
                'wgDBmwschema',
        );
 
+       protected $internalDefaults = array(
+               '_InstallUser' => 'postgres',
+       );
+
        var $minimumVersion = '8.3';
-       private $useAdmin = false;
+       var $maxRoleSearchDepth = 5;
+
+       protected $pgConns = array();
 
        function getName() {
                return 'postgres';
@@ -39,7 +60,7 @@ class PostgresInstaller extends DatabaseInstaller {
                        $this->getTextBox( 'wgDBserver', 'config-db-host', array(), $this->parent->getHelpBox( 'config-db-host-help' ) ) .
                        $this->getTextBox( 'wgDBport', 'config-db-port' ) .
                        Html::openElement( 'fieldset' ) .
-                       Html::element( 'legend', array(), wfMsg( 'config-db-wiki-settings' ) ) .
+                       Html::element( 'legend', array(), wfMessage( 'config-db-wiki-settings' )->text() ) .
                        $this->getTextBox( 'wgDBname', 'config-db-name', array(), $this->parent->getHelpBox( 'config-db-name-help' ) ) .
                        $this->getTextBox( 'wgDBmwschema', 'config-db-schema', array(), $this->parent->getHelpBox( 'config-db-schema-help' ) ) .
                        Html::closeElement( 'fieldset' ) .
@@ -70,48 +91,53 @@ class PostgresInstaller extends DatabaseInstaller {
                        return $status;
                }
 
-               $this->useAdmin = true;
-               // Try to connect
-               $status->merge( $this->getConnection() );
-               if ( !$status->isOK() ) {
-                       return $status;
-               }
-
-               //Make sure install user can create
-               if( !$this->canCreateAccounts() ) {
-                       $status->fatal( 'config-pg-no-create-privs' );
-               }
+               $status = $this->getPgConnection( 'create-db' );
                if ( !$status->isOK() ) {
                        return $status;
                }
+               /**
+                * @var $conn DatabaseBase
+                */
+               $conn = $status->value;
 
                // Check version
-               $version = $this->db->getServerVersion();
+               $version = $conn->getServerVersion();
                if ( version_compare( $version, $this->minimumVersion ) < 0 ) {
                        return Status::newFatal( 'config-postgres-old', $this->minimumVersion, $version );
                }
 
                $this->setVar( 'wgDBuser', $this->getVar( '_InstallUser' ) );
                $this->setVar( 'wgDBpassword', $this->getVar( '_InstallPassword' ) );
+               return Status::newGood();
+       }
+
+       public function getConnection() {
+               $status = $this->getPgConnection( 'create-tables' );
+               if ( $status->isOK() ) {
+                       $this->db = $status->value;
+               }
                return $status;
        }
 
        public function openConnection() {
+               return $this->openPgConnection( 'create-tables' );
+       }
+
+       /**
+        * Open a PG connection with given parameters
+        * @param $user string User name
+        * @param $password string Password
+        * @param $dbName string Database name
+        * @return Status
+        */
+       protected function openConnectionWithParams( $user, $password, $dbName ) {
                $status = Status::newGood();
                try {
-                       if ( $this->useAdmin ) {
-                               $db = new DatabasePostgres(
-                                       $this->getVar( 'wgDBserver' ),
-                                       $this->getVar( '_InstallUser' ),
-                                       $this->getVar( '_InstallPassword' ),
-                                       'template1' );
-                       } else {
-                               $db = new DatabasePostgres(
-                                       $this->getVar( 'wgDBserver' ),
-                                       $this->getVar( 'wgDBuser' ),
-                                       $this->getVar( 'wgDBpassword' ),
-                                       $this->getVar( 'wgDBname' ) );
-                       }
+                       $db = new DatabasePostgres(
+                               $this->getVar( 'wgDBserver' ),
+                               $user,
+                               $password,
+                               $dbName);
                        $status->value = $db;
                } catch ( DBConnectionError $e ) {
                        $status->fatal( 'config-connection-error', $e->getMessage() );
@@ -119,29 +145,144 @@ class PostgresInstaller extends DatabaseInstaller {
                return $status;
        }
 
-       protected function canCreateAccounts() {
-               $this->useAdmin = true;
-               $status = $this->getConnection();
+       /**
+        * Get a special type of connection
+        * @param $type string See openPgConnection() for details.
+        * @return Status
+        */
+       protected function getPgConnection( $type ) {
+               if ( isset( $this->pgConns[$type] ) ) {
+                       return Status::newGood( $this->pgConns[$type] );
+               }
+               $status = $this->openPgConnection( $type );
+
+               if ( $status->isOK() ) {
+                       /**
+                        * @var $conn DatabaseBase
+                        */
+                       $conn = $status->value;
+                       $conn->clearFlag( DBO_TRX );
+                       $conn->commit( __METHOD__ );
+                       $this->pgConns[$type] = $conn;
+               }
+               return $status;
+       }
+
+       /**
+        * Get a connection of a specific PostgreSQL-specific type. Connections
+        * of a given type are cached.
+        *
+        * PostgreSQL lacks cross-database operations, so after the new database is
+        * created, you need to make a separate connection to connect to that
+        * database and add tables to it.
+        *
+        * New tables are owned by the user that creates them, and MediaWiki's
+        * PostgreSQL support has always assumed that the table owner will be
+        * $wgDBuser. So before we create new tables, we either need to either
+        * connect as the other user or to execute a SET ROLE command. Using a
+        * separate connection for this allows us to avoid accidental cross-module
+        * dependencies.
+        *
+        * @param $type string The type of connection to get:
+        *    - create-db:     A connection for creating DBs, suitable for pre-
+        *                     installation.
+        *    - create-schema: A connection to the new DB, for creating schemas and
+        *                     other similar objects in the new DB.
+        *    - create-tables: A connection with a role suitable for creating tables.
+        *
+        * @return Status object. On success, a connection object will be in the
+        *   value member.
+        */
+       protected function openPgConnection( $type ) {
+               switch ( $type ) {
+                       case 'create-db':
+                               return $this->openConnectionToAnyDB(
+                                       $this->getVar( '_InstallUser' ),
+                                       $this->getVar( '_InstallPassword' ) );
+                       case 'create-schema':
+                               return $this->openConnectionWithParams(
+                                       $this->getVar( '_InstallUser' ),
+                                       $this->getVar( '_InstallPassword' ),
+                                       $this->getVar( 'wgDBname' ) );
+                       case 'create-tables':
+                               $status = $this->openPgConnection( 'create-schema' );
+                               if ( $status->isOK() ) {
+                                       /**
+                                        * @var $conn DatabaseBase
+                                        */
+                                       $conn = $status->value;
+                                       $safeRole = $conn->addIdentifierQuotes( $this->getVar( 'wgDBuser' ) );
+                                       $conn->query( "SET ROLE $safeRole" );
+                               }
+                               return $status;
+                       default:
+                               throw new MWException( "Invalid special connection type: \"$type\"" );
+               }
+       }
+
+       public function openConnectionToAnyDB( $user, $password ) {
+               $dbs = array(
+                       'template1',
+                       'postgres',
+               );
+               if ( !in_array( $this->getVar( 'wgDBname' ), $dbs ) ) {
+                       array_unshift( $dbs, $this->getVar( 'wgDBname' ) );
+               }
+               $conn = false;
+               $status = Status::newGood();
+               foreach ( $dbs as $db ) {
+                       try {
+                               $conn = new DatabasePostgres(
+                                       $this->getVar( 'wgDBserver' ),
+                                       $user,
+                                       $password,
+                                       $db );
+                       } catch ( DBConnectionError $error ) {
+                               $conn = false;
+                               $status->fatal( 'config-pg-test-error', $db,
+                                       $error->getMessage() );
+                       }
+                       if ( $conn !== false ) {
+                               break;
+                       }
+               }
+               if ( $conn !== false ) {
+                       return Status::newGood( $conn );
+               } else {
+                       return $status;
+               }
+       }
+
+       protected function getInstallUserPermissions() {
+               $status = $this->getPgConnection( 'create-db' );
                if ( !$status->isOK() ) {
                        return false;
                }
+               /**
+                * @var $conn DatabaseBase
+                */
                $conn = $status->value;
-
                $superuser = $this->getVar( '_InstallUser' );
 
-               $rights = $conn->selectField( 'pg_catalog.pg_user',
-                       'CASE WHEN usesuper IS TRUE THEN
-                               CASE WHEN usecreatedb IS TRUE THEN 3 ELSE 1 END
-                               ELSE CASE WHEN usecreatedb IS TRUE THEN 2 ELSE 0 END
-                               END AS rights',
-                       array( 'usename' => $superuser ), __METHOD__
-               );
+               $row = $conn->selectRow( '"pg_catalog"."pg_roles"', '*',
+                       array( 'rolname' => $superuser ), __METHOD__ );
+               return $row;
+       }
 
-               if( !$rights || ( $rights != 1 && $rights != 3 ) ) {
+       protected function canCreateAccounts() {
+               $perms = $this->getInstallUserPermissions();
+               if ( !$perms ) {
                        return false;
                }
+               return $perms->rolsuper === 't' || $perms->rolcreaterole === 't';
+       }
 
-               return true;
+       protected function isSuperUser() {
+               $perms = $this->getInstallUserPermissions();
+               if ( !$perms ) {
+                       return false;
+               }
+               return $perms->rolsuper === 't';
        }
 
        public function getSettingsForm() {
@@ -161,103 +302,188 @@ class PostgresInstaller extends DatabaseInstaller {
                        return $status;
                }
 
+               $same = $this->getVar( 'wgDBuser' ) === $this->getVar( '_InstallUser' );
+
+               if ( $same ) {
+                       $exists = true;
+               } else {
+                       // Check if the web user exists
+                       // Connect to the database with the install user
+                       $status = $this->getPgConnection( 'create-db' );
+                       if ( !$status->isOK() ) {
+                               return $status;
+                       }
+                       $exists = $status->value->roleExists( $this->getVar( 'wgDBuser' ) );
+               }
+
                // Validate the create checkbox
-               $canCreate = $this->canCreateAccounts();
-               if ( $canCreate ) {
+               if ( $this->canCreateAccounts() && !$same && !$exists ) {
+                       $create = $this->getVar( '_CreateDBAccount' );
+               } else {
                        $this->setVar( '_CreateDBAccount', false );
                        $create = false;
-               } else {
-                       $create = $this->getVar( '_CreateDBAccount' );
                }
 
-               // Don't test the web account if it is the same as the admin.
-               if ( !$create && $this->getVar( 'wgDBuser' ) != $this->getVar( '_InstallUser' ) ) {
-                       // Test the web account
-                       try {
-                               $this->useAdmin = false;
-                               return $this->openConnection();
-                       } catch ( DBConnectionError $e ) {
-                               return Status::newFatal( 'config-connection-error', $e->getMessage() );
+               if ( !$create && !$exists ) {
+                       if ( $this->canCreateAccounts() ) {
+                               $msg = 'config-install-user-missing-create';
+                       } else {
+                               $msg = 'config-install-user-missing';
                        }
+                       return Status::newFatal( $msg, $this->getVar( 'wgDBuser' ) );
                }
 
-               return Status::newGood();
+               if ( !$exists ) {
+                       // No more checks to do
+                       return Status::newGood();
+               }
+
+               // Existing web account. Test the connection.
+               $status = $this->openConnectionToAnyDB(
+                       $this->getVar( 'wgDBuser' ),
+                       $this->getVar( 'wgDBpassword' ) );
+               if ( !$status->isOK() ) {
+                       return $status;
+               }
+
+               // The web user is conventionally the table owner in PostgreSQL
+               // installations. Make sure the install user is able to create
+               // objects on behalf of the web user.
+               if ( $same || $this->canCreateObjectsForWebUser() ) {
+                       return Status::newGood();
+               } else {
+                       return Status::newFatal( 'config-pg-not-in-role' );
+               }
+       }
+
+       /**
+        * Returns true if the install user is able to create objects owned
+        * by the web user, false otherwise.
+        * @return bool
+        */
+       protected function canCreateObjectsForWebUser() {
+               if ( $this->isSuperUser() ) {
+                       return true;
+               }
+
+               $status = $this->getPgConnection( 'create-db' );
+               if ( !$status->isOK() ) {
+                       return false;
+               }
+               $conn = $status->value;
+               $installerId = $conn->selectField( '"pg_catalog"."pg_roles"', 'oid',
+                       array( 'rolname' => $this->getVar( '_InstallUser' ) ), __METHOD__ );
+               $webId = $conn->selectField( '"pg_catalog"."pg_roles"', 'oid',
+                       array( 'rolname' => $this->getVar( 'wgDBuser' ) ), __METHOD__ );
+
+               return $this->isRoleMember( $conn, $installerId, $webId, $this->maxRoleSearchDepth );
+       }
+
+       /**
+        * Recursive helper for canCreateObjectsForWebUser().
+        * @param $conn DatabaseBase object
+        * @param $targetMember int Role ID of the member to look for
+        * @param $group int Role ID of the group to look for
+        * @param $maxDepth int Maximum recursive search depth
+        * @return bool
+        */
+       protected function isRoleMember( $conn, $targetMember, $group, $maxDepth ) {
+               if ( $targetMember === $group ) {
+                       // A role is always a member of itself
+                       return true;
+               }
+               // Get all members of the given group
+               $res = $conn->select( '"pg_catalog"."pg_auth_members"', array( 'member' ),
+                       array( 'roleid' => $group ), __METHOD__ );
+               foreach ( $res as $row ) {
+                       if ( $row->member == $targetMember ) {
+                               // Found target member
+                               return true;
+                       }
+                       // Recursively search each member of the group to see if the target
+                       // is a member of it, up to the given maximum depth.
+                       if ( $maxDepth > 0 ) {
+                               if ( $this->isRoleMember( $conn, $targetMember, $row->member, $maxDepth - 1 ) ) {
+                                       // Found member of member
+                                       return true;
+                               }
+                       }
+               }
+               return false;
        }
 
        public function preInstall() {
+               $createDbAccount = array(
+                       'name' => 'user',
+                       'callback' => array( $this, 'setupUser' ),
+               );
                $commitCB = array(
                        'name' => 'pg-commit',
                        'callback' => array( $this, 'commitChanges' ),
                );
-               $userCB = array(
-                       'name' => 'user',
-                       'callback' => array( $this, 'setupUser' ),
-               );
                $plpgCB = array(
                        'name' => 'pg-plpgsql',
                        'callback' => array( $this, 'setupPLpgSQL' ),
                );
+               $schemaCB = array(
+                       'name' => 'schema',
+                       'callback' => array( $this, 'setupSchema' )
+               );
+
+               if( $this->getVar( '_CreateDBAccount' ) ) {
+                       $this->parent->addInstallStep( $createDbAccount, 'database' );
+               }
                $this->parent->addInstallStep( $commitCB, 'interwiki' );
-               $this->parent->addInstallStep( $userCB );
                $this->parent->addInstallStep( $plpgCB, 'database' );
+               $this->parent->addInstallStep( $schemaCB, 'database' );
        }
 
        function setupDatabase() {
-               $this->useAdmin = true;
-               $status = $this->getConnection();
+               $status = $this->getPgConnection( 'create-db' );
                if ( !$status->isOK() ) {
                        return $status;
                }
-               $this->setupSchemaVars();
                $conn = $status->value;
 
                $dbName = $this->getVar( 'wgDBname' );
-               $SQL = "SELECT 1 FROM pg_catalog.pg_database WHERE datname = " . $conn->addQuotes( $dbName );
-               $rows = $conn->numRows( $conn->query( $SQL ) );
-               if( !$rows ) {
-                       $schema = $this->getVar( 'wgDBmwschema' );
-                       $user = $this->getVar( 'wgDBuser' );
-
-                       $safeschema = $conn->addIdentifierQuotes( $schema );
-                       $safeuser = $conn->addIdentifierQuotes( $user );
 
+               $exists = $conn->selectField( '"pg_catalog"."pg_database"', '1',
+                       array( 'datname' => $dbName ), __METHOD__ );
+               if ( !$exists ) {
                        $safedb = $conn->addIdentifierQuotes( $dbName );
+                       $conn->query( "CREATE DATABASE $safedb", __METHOD__ );
+               }
+               return Status::newGood();
+       }
 
-                       $conn->query( "CREATE DATABASE $safedb OWNER $safeuser", __METHOD__ );
-
-                       $this->useAdmin = false;
-                       $status = $this->getConnection();
-                       if ( !$status->isOK() ) {
-                               return $status;
-                       }
-                       $conn = $status->value;
+       function setupSchema() {
+               // Get a connection to the target database
+               $status = $this->getPgConnection( 'create-schema' );
+               if ( !$status->isOK() ) {
+                       return $status;
+               }
+               $conn = $status->value;
 
-                       $result = $conn->schemaExists( $schema );
-                       if( !$result ) {
-                               $result = $conn->query( "CREATE SCHEMA $safeschema AUTHORIZATION $safeuser" );
-                               if( !$result ) {
-                                       $status->fatal( 'config-install-pg-schema-failed', $user, $schema );
-                               }
-                       } else {
-                               $safeschema2 = $conn->addQuotes( $schema );
-                               $SQL = "SELECT 'GRANT ALL ON '||pg_catalog.quote_ident(relname)||' TO $safeuser;'\n".
-                                       "FROM pg_catalog.pg_class p, pg_catalog.pg_namespace n\n" .
-                                       "WHERE relnamespace = n.oid AND n.nspname = $safeschema2\n" .
-                                       "AND p.relkind IN ('r','S','v')\n";
-                               $SQL .= "UNION\n";
-                               $SQL .= "SELECT 'GRANT ALL ON FUNCTION '||pg_catalog.quote_ident(proname)||'('||\n".
-                                       "pg_catalog.oidvectortypes(p.proargtypes)||') TO $safeuser;'\n" .
-                                       "FROM pg_catalog.pg_proc p, pg_catalog.pg_namespace n\n" .
-                                       "WHERE p.pronamespace = n.oid AND n.nspname = $safeschema2";
-                               $conn->query( "SET search_path = $safeschema" );
-                               $res = $conn->query( $SQL );
+               // Create the schema if necessary
+               $schema = $this->getVar( 'wgDBmwschema' );
+               $safeschema = $conn->addIdentifierQuotes( $schema );
+               $safeuser = $conn->addIdentifierQuotes( $this->getVar( 'wgDBuser' ) );
+               if( !$conn->schemaExists( $schema ) ) {
+                       try {
+                               $conn->query( "CREATE SCHEMA $safeschema AUTHORIZATION $safeuser" );
+                       } catch ( DBQueryError $e ) {
+                               return Status::newFatal( 'config-install-pg-schema-failed',
+                                       $this->getVar( '_InstallUser' ), $schema );
                        }
                }
-               return $status;
+
+               // Select the new schema in the current connection
+               $conn->determineCoreSchema( $schema );
+               return Status::newGood();
        }
 
        function commitChanges() {
-               $this->db->query( 'COMMIT' );
+               $this->db->commit( __METHOD__ );
                return Status::newGood();
        }
 
@@ -266,31 +492,37 @@ class PostgresInstaller extends DatabaseInstaller {
                        return Status::newGood();
                }
 
-               $this->useAdmin = true;
-               $status = $this->getConnection();
-
+               $status = $this->getPgConnection( 'create-db' );
                if ( !$status->isOK() ) {
                        return $status;
                }
+               $conn = $status->value;
 
-               $schema = $this->getVar( 'wgDBmwschema' );
-               $safeuser = $this->db->addIdentifierQuotes( $this->getVar( 'wgDBuser' ) );
-               $safeusercheck = $this->db->addQuotes( $this->getVar( 'wgDBuser' ) );
-               $safepass = $this->db->addQuotes( $this->getVar( 'wgDBpassword' ) );
-               $safeschema = $this->db->addIdentifierQuotes( $schema );
+               $safeuser = $conn->addIdentifierQuotes( $this->getVar( 'wgDBuser' ) );
+               $safepass = $conn->addQuotes( $this->getVar( 'wgDBpassword' ) );
 
-               $rows = $this->db->numRows(
-                       $this->db->query( "SELECT 1 FROM pg_catalog.pg_shadow WHERE usename = $safeusercheck" )
-               );
-               if ( $rows < 1 ) {
-                       $res = $this->db->query( "CREATE USER $safeuser NOCREATEDB PASSWORD $safepass", __METHOD__ );
-                       if ( $res !== true && !( $res instanceOf ResultWrapper ) ) {
-                               $status->fatal( 'config-install-user-failed', $this->getVar( 'wgDBuser' ), $res );
+               // Check if the user already exists
+               $userExists = $conn->roleExists( $this->getVar( 'wgDBuser' ) );
+               if ( !$userExists ) {
+                       // Create the user
+                       try {
+                               $sql = "CREATE ROLE $safeuser NOCREATEDB LOGIN PASSWORD $safepass";
+
+                               // If the install user is not a superuser, we need to make the install
+                               // user a member of the new user's group, so that the install user will
+                               // be able to create a schema and other objects on behalf of the new user.
+                               if ( !$this->isSuperUser() ) {
+                                       $sql .= ' ROLE' . $conn->addIdentifierQuotes( $this->getVar( '_InstallUser' ) );
+                               }
+
+                               $conn->query( $sql, __METHOD__ );
+                       } catch ( DBQueryError $e ) {
+                               return Status::newFatal( 'config-install-user-create-failed',
+                                       $this->getVar( 'wgDBuser' ), $e->getMessage() );
                        }
-                       $this->db->query("ALTER USER $safeuser SET search_path = $safeschema");
                }
 
-               return $status;
+               return Status::newGood();
        }
 
        function getLocalSettings() {
@@ -314,36 +546,35 @@ class PostgresInstaller extends DatabaseInstaller {
        public function createTables() {
                $schema = $this->getVar( 'wgDBmwschema' );
 
-               $this->db = null;
-               $this->useAdmin = false;
                $status = $this->getConnection();
                if ( !$status->isOK() ) {
                        return $status;
                }
-               $this->db->selectDB( $this->getVar( 'wgDBname' ) );
 
-               if( $this->db->tableExists( 'user' ) ) {
+               /**
+                * @var $conn DatabaseBase
+                */
+               $conn = $status->value;
+
+               if( $conn->tableExists( 'archive' ) ) {
                        $status->warning( 'config-install-tables-exist' );
+                       $this->enableLB();
                        return $status;
                }
 
-               $this->db->setFlag( DBO_DDLMODE ); // For Oracle's handling of schema files
-               $this->db->begin( __METHOD__ );
-
+               $conn->begin( __METHOD__ );
 
-               if( !$this->db->schemaExists( $schema ) ) {
-                       $status->error( 'config-install-pg-schema-not-exist' );
+               if( !$conn->schemaExists( $schema ) ) {
+                       $status->fatal( 'config-install-pg-schema-not-exist' );
                        return $status;
                }
-               $safeschema = $this->db->addIdentifierQuotes( $schema );
-               $this->db->query( "SET search_path = $safeschema" );
-               $error = $this->db->sourceFile( $this->db->getSchema() );
+               $error = $conn->sourceFile( $conn->getSchemaPath() );
                if( $error !== true ) {
-                       $this->db->reportQueryError( $error, 0, '', __METHOD__ );
-                       $this->db->rollback( __METHOD__ );
+                       $conn->reportQueryError( $error, 0, '', __METHOD__ );
+                       $conn->rollback( __METHOD__ );
                        $status->fatal( 'config-install-tables-failed', $error );
                } else {
-                       $this->db->commit( __METHOD__ );
+                       $conn->commit( __METHOD__ );
                }
                // Resume normal operations
                if( $status->isOk() ) {
@@ -353,29 +584,43 @@ class PostgresInstaller extends DatabaseInstaller {
        }
 
        public function setupPLpgSQL() {
-               $this->useAdmin = true;
-               $status = $this->getConnection();
+               // Connect as the install user, since it owns the database and so is
+               // the user that needs to run "CREATE LANGAUGE"
+               $status = $this->getPgConnection( 'create-schema' );
                if ( !$status->isOK() ) {
                        return $status;
                }
+               /**
+                * @var $conn DatabaseBase
+                */
+               $conn = $status->value;
 
-               $rows = $this->db->numRows(
-                       $this->db->query( "SELECT 1 FROM pg_catalog.pg_language WHERE lanname = 'plpgsql'" )
-               );
-               if ( $rows < 1 ) {
-                       // plpgsql is not installed, but if we have a pg_pltemplate table, we should be able to create it
-                       $SQL = "SELECT 1 FROM pg_catalog.pg_class c JOIN pg_catalog.pg_namespace n ON (n.oid = c.relnamespace) ".
-                               "WHERE relname = 'pg_pltemplate' AND nspname='pg_catalog'";
-                       $rows = $this->db->numRows( $this->db->query( $SQL ) );
-                       $dbName = $this->getVar( 'wgDBname' );
-                       if ( $rows >= 1 ) {
-                               $result = $this->db->query( 'CREATE LANGUAGE plpgsql' );
-                               if ( !$result ) {
-                                       return Status::newFatal( 'config-pg-no-plpgsql', $dbName );
-                               }
-                       } else {
-                               return Status::newFatal( 'config-pg-no-plpgsql', $dbName );
+               $exists = $conn->selectField( '"pg_catalog"."pg_language"', 1,
+                       array( 'lanname' => 'plpgsql' ), __METHOD__ );
+               if ( $exists ) {
+                       // Already exists, nothing to do
+                       return Status::newGood();
+               }
+
+               // plpgsql is not installed, but if we have a pg_pltemplate table, we
+               // should be able to create it
+               $exists = $conn->selectField(
+                       array( '"pg_catalog"."pg_class"', '"pg_catalog"."pg_namespace"' ),
+                       1,
+                       array(
+                               'pg_namespace.oid=relnamespace',
+                               'nspname' => 'pg_catalog',
+                               'relname' => 'pg_pltemplate',
+                       ),
+                       __METHOD__ );
+               if ( $exists ) {
+                       try {
+                               $conn->query( 'CREATE LANGUAGE plpgsql' );
+                       } catch ( DBQueryError $e ) {
+                               return Status::newFatal( 'config-pg-no-plpgsql', $this->getVar( 'wgDBname' ) );
                        }
+               } else {
+                       return Status::newFatal( 'config-pg-no-plpgsql', $this->getVar( 'wgDBname' ) );
                }
                return Status::newGood();
        }