includes/db/DatabasePostgres.php

   1 <?php
   2 /**
   3  * This is the Postgres database abstraction layer.
   4  *
   5  * @file
   6  * @ingroup Database
   7  */
   8
   9 class PostgresField implements Field {
  10         private $name, $tablename, $type, $nullable, $max_length, $deferred, $deferrable, $conname;
  11
  12         static function fromText($db, $table, $field) {
  13         global $wgDBmwschema;
  14
  15                 $q = <<<SQL
  16 SELECT
  17  attnotnull, attlen, COALESCE(conname, '') AS conname,
  18  COALESCE(condeferred, 'f') AS deferred,
  19  COALESCE(condeferrable, 'f') AS deferrable,
  20  CASE WHEN typname = 'int2' THEN 'smallint'
  21   WHEN typname = 'int4' THEN 'integer'
  22   WHEN typname = 'int8' THEN 'bigint'
  23   WHEN typname = 'bpchar' THEN 'char'
  24  ELSE typname END AS typname
  25 FROM pg_class c
  26 JOIN pg_namespace n ON (n.oid = c.relnamespace)
  27 JOIN pg_attribute a ON (a.attrelid = c.oid)
  28 JOIN pg_type t ON (t.oid = a.atttypid)
  29 LEFT JOIN pg_constraint o ON (o.conrelid = c.oid AND a.attnum = ANY(o.conkey) AND o.contype = 'f')
  30 WHERE relkind = 'r'
  31 AND nspname=%s
  32 AND relname=%s
  33 AND attname=%s;
  34 SQL;
  35
  36                 $table = $db->tableName( $table );
  37                 $res = $db->query(
  38                         sprintf( $q,
  39                                 $db->addQuotes( $wgDBmwschema ),
  40                                 $db->addQuotes( $table ),
  41                                 $db->addQuotes( $field )
  42                         )
  43                 );
  44                 $row = $db->fetchObject( $res );
  45                 if ( !$row ) {
  46                         return null;
  47                 }
  48                 $n = new PostgresField;
  49                 $n->type = $row->typname;
  50                 $n->nullable = ( $row->attnotnull == 'f' );
  51                 $n->name = $field;
  52                 $n->tablename = $table;
  53                 $n->max_length = $row->attlen;
  54                 $n->deferrable = ( $row->deferrable == 't' );
  55                 $n->deferred = ( $row->deferred == 't' );
  56                 $n->conname = $row->conname;
  57                 return $n;
  58         }
  59
  60         function name() {
  61                 return $this->name;
  62         }
  63
  64         function tableName() {
  65                 return $this->tablename;
  66         }
  67
  68         function type() {
  69                 return $this->type;
  70         }
  71
  72         function isNullable() {
  73                 return $this->nullable;
  74         }
  75
  76         function maxLength() {
  77                 return $this->max_length;
  78         }
  79
  80         function is_deferrable() {
  81                 return $this->deferrable;
  82         }
  83
  84         function is_deferred() {
  85                 return $this->deferred;
  86         }
  87
  88         function conname() {
  89                 return $this->conname;
  90         }
  91
  92 }
  93
  94 /**
  95  * @ingroup Database
  96  */
  97 class DatabasePostgres extends DatabaseBase {
  98         var $mInsertId = null;
  99         var $mLastResult = null;
 100         var $numeric_version = null;
 101         var $mAffectedRows = null;
 102
 103         function __construct( $server = false, $user = false, $password = false, $dbName = false,
 104                 $flags = 0 )
 105         {
 106                 $this->mFlags = $flags;
 107                 $this->open( $server, $user, $password, $dbName );
 108         }
 109
 110         function getType() {
 111                 return 'postgres';
 112         }
 113
 114         function cascadingDeletes() {
 115                 return true;
 116         }
 117         function cleanupTriggers() {
 118                 return true;
 119         }
 120         function strictIPs() {
 121                 return true;
 122         }
 123         function realTimestamps() {
 124                 return true;
 125         }
 126         function implicitGroupby() {
 127                 return false;
 128         }
 129         function implicitOrderby() {
 130                 return false;
 131         }
 132         function searchableIPs() {
 133                 return true;
 134         }
 135         function functionalIndexes() {
 136                 return true;
 137         }
 138
 139         function hasConstraint( $name ) {
 140                 global $wgDBmwschema;
 141                 $SQL = "SELECT 1 FROM pg_catalog.pg_constraint c, pg_catalog.pg_namespace n WHERE c.connamespace = n.oid AND conname = '" .
 142                                 pg_escape_string( $this->mConn, $name ) . "' AND n.nspname = '" . pg_escape_string( $this->mConn, $wgDBmwschema ) ."'";
 143                 $res = $this->doQuery( $SQL );
 144                 return $this->numRows( $res );
 145         }
 146
 147         static function newFromParams( $server, $user, $password, $dbName, $flags = 0 ) {
 148                 return new DatabasePostgres( $server, $user, $password, $dbName, $flags );
 149         }
 150
 151         /**
 152          * Usually aborts on failure
 153          */
 154         function open( $server, $user, $password, $dbName ) {
 155                 # Test for Postgres support, to avoid suppressed fatal error
 156                 if ( !function_exists( 'pg_connect' ) ) {
 157                         throw new DBConnectionError( $this, "Postgres functions missing, have you compiled PHP with the --with-pgsql option?\n (Note: if you recently installed PHP, you may need to restart your webserver and database)\n" );
 158                 }
 159
 160                 global $wgDBport;
 161
 162                 if ( !strlen( $user ) ) { # e.g. the class is being loaded
 163                         return;
 164                 }
 165                 $this->close();
 166                 $this->mServer = $server;
 167                 $this->mPort = $port = $wgDBport;
 168                 $this->mUser = $user;
 169                 $this->mPassword = $password;
 170                 $this->mDBname = $dbName;
 171
 172                 $connectVars = array(
 173                         'dbname' => $dbName,
 174                         'user' => $user,
 175                         'password' => $password
 176                 );
 177                 if ( $server != false && $server != '' ) {
 178                         $connectVars['host'] = $server;
 179                 }
 180                 if ( $port != false && $port != '' ) {
 181                         $connectVars['port'] = $port;
 182                 }
 183                 $connectString = $this->makeConnectionString( $connectVars, PGSQL_CONNECT_FORCE_NEW );
 184
 185                 $this->installErrorHandler();
 186                 $this->mConn = pg_connect( $connectString );
 187                 $phpError = $this->restoreErrorHandler();
 188
 189                 if ( !$this->mConn ) {
 190                         wfDebug( "DB connection error\n" );
 191                         wfDebug( "Server: $server, Database: $dbName, User: $user, Password: " . substr( $password, 0, 3 ) . "...\n" );
 192                         wfDebug( $this->lastError() . "\n" );
 193                         throw new DBConnectionError( $this, $phpError );
 194                 }
 195
 196                 $this->mOpened = true;
 197
 198                 global $wgCommandLineMode;
 199                 # If called from the command-line (e.g. importDump), only show errors
 200                 if ( $wgCommandLineMode ) {
 201                         $this->doQuery( "SET client_min_messages = 'ERROR'" );
 202                 }
 203
 204                 $this->doQuery( "SET client_encoding='UTF8'" );
 205
 206                 global $wgDBmwschema, $wgDBts2schema;
 207                 if ( isset( $wgDBmwschema ) && isset( $wgDBts2schema )
 208                         && $wgDBmwschema !== 'mediawiki'
 209                         && preg_match( '/^\w+$/', $wgDBmwschema )
 210                         && preg_match( '/^\w+$/', $wgDBts2schema )
 211                 ) {
 212                         $safeschema = $this->addIdentifierQuotes( $wgDBmwschema );
 213                         $this->doQuery( "SET search_path = $safeschema, $wgDBts2schema, public" );
 214                 }
 215
 216                 return $this->mConn;
 217         }
 218
 219         function makeConnectionString( $vars ) {
 220                 $s = '';
 221                 foreach ( $vars as $name => $value ) {
 222                         $s .= "$name='" . str_replace( "'", "\\'", $value ) . "' ";
 223                 }
 224                 return $s;
 225         }
 226
 227
 228         function initial_setup( $superuser, $password, $dbName ) {
 229                 // If this is the initial connection, setup the schema stuff and possibly create the user
 230                 global $wgDBname, $wgDBuser, $wgDBpassword, $wgDBmwschema, $wgDBts2schema;
 231
 232                 $safeuser = $this->addIdentifierQuotes( $wgDBuser );
 233                 // Are we connecting as a superuser for the first time?
 234                 if ( $superuser ) {
 235                         // Are we really a superuser? Check out our rights
 236                         $SQL = "SELECT
 237                       CASE WHEN usesuper IS TRUE THEN
 238                       CASE WHEN usecreatedb IS TRUE THEN 3 ELSE 1 END
 239                       ELSE CASE WHEN usecreatedb IS TRUE THEN 2 ELSE 0 END
 240                     END AS rights
 241                     FROM pg_catalog.pg_user WHERE usename = " . $this->addQuotes( $superuser );
 242                         $rows = $this->numRows( $res = $this->doQuery( $SQL ) );
 243                         if ( !$rows ) {
 244                                 print '<li>ERROR: Could not read permissions for user "' . htmlspecialchars( $superuser ) . "\"</li>\n";
 245                                 dieout( );
 246                         }
 247                         $perms = pg_fetch_result( $res, 0, 0 );
 248
 249                         $SQL = "SELECT 1 FROM pg_catalog.pg_user WHERE usename = " . $this->addQuotes( $wgDBuser );
 250                         $rows = $this->numRows( $this->doQuery( $SQL ) );
 251                         if ( $rows ) {
 252                                 print '<li>User "' . htmlspecialchars( $wgDBuser ) . '" already exists, skipping account creation.</li>';
 253                         } else {
 254                                 if ( $perms != 1 && $perms != 3 ) {
 255                                         print '<li>ERROR: the user "' . htmlspecialchars( $superuser ) . '" cannot create other users. ';
 256                                         print 'Please use a different Postgres user.</li>';
 257                                         dieout( );
 258                                 }
 259                                 print '<li>Creating user <b>' . htmlspecialchars( $wgDBuser ) . '</b>...';
 260                                 $safepass = $this->addQuotes( $wgDBpassword );
 261                                 $SQL = "CREATE USER $safeuser NOCREATEDB PASSWORD $safepass";
 262                                 $this->doQuery( $SQL );
 263                                 print "OK</li>\n";
 264                         }
 265                         // User now exists, check out the database
 266                         if ( $dbName != $wgDBname ) {
 267                                 $SQL = "SELECT 1 FROM pg_catalog.pg_database WHERE datname = " . $this->addQuotes( $wgDBname );
 268                                 $rows = $this->numRows( $this->doQuery( $SQL ) );
 269                                 if ( $rows ) {
 270                                         print '<li>Database "' . htmlspecialchars( $wgDBname ) . '" already exists, skipping database creation.</li>';
 271                                 } else {
 272                                         if ( $perms < 1 ) {
 273                                                 print '<li>ERROR: the user "' . htmlspecialchars( $superuser ) . '" cannot create databases. ';
 274                                                 print 'Please use a different Postgres user.</li>';
 275                                                 dieout( );
 276                                         }
 277                                         print '<li>Creating database <b>' . htmlspecialchars( $wgDBname ) . '</b>...';
 278                                         $safename = $this->addIdentifierQuotes( $wgDBname );
 279                                         $SQL = "CREATE DATABASE $safename OWNER $safeuser ";
 280                                         $this->doQuery( $SQL );
 281                                         print "OK</li>\n";
 282                                         // Hopefully tsearch2 and plpgsql are in template1...
 283                                 }
 284
 285                                 // Reconnect to check out tsearch2 rights for this user
 286                                 print '<li>Connecting to "' . htmlspecialchars( $wgDBname ) . '" as superuser "' .
 287                                         htmlspecialchars( $superuser ) . '" to check rights...';
 288
 289                                 $connectVars = array();
 290                                 if ( $this->mServer != false && $this->mServer != '' ) {
 291                                         $connectVars['host'] = $this->mServer;
 292                                 }
 293                                 if ( $this->mPort != false && $this->mPort != '' ) {
 294                                         $connectVars['port'] = $this->mPort;
 295                                 }
 296                                 $connectVars['dbname'] = $wgDBname;
 297                                 $connectVars['user'] = $superuser;
 298                                 $connectVars['password'] = $password;
 299
 300                                 @$this->mConn = pg_connect( $this->makeConnectionString( $connectVars ) );
 301                                 if ( !$this->mConn ) {
 302                                         print "<b>FAILED TO CONNECT!</b></li>";
 303                                         dieout( );
 304                                 }
 305                                 print "OK</li>\n";
 306                         }
 307
 308                         if ( $this->numeric_version < 8.3 ) {
 309                                 // Tsearch2 checks
 310                                 print '<li>Checking that tsearch2 is installed in the database "' .
 311                                         htmlspecialchars( $wgDBname ) . '"...';
 312                                 if ( !$this->tableExists( 'pg_ts_cfg', $wgDBts2schema ) ) {
 313                                         print '<b>FAILED</b>. tsearch2 must be installed in the database "' .
 314                                                 htmlspecialchars( $wgDBname ) . '".';
 315                                         print 'Please see <a href="http://www.devx.com/opensource/Article/21674/0/page/2">this article</a>';
 316                                         print " for instructions or ask on #postgresql on irc.freenode.net</li>\n";
 317                                         dieout( );
 318                                 }
 319                                 print "OK</li>\n";
 320                                 print '<li>Ensuring that user "' . htmlspecialchars( $wgDBuser ) .
 321                                         '" has select rights on the tsearch2 tables...';
 322                                 foreach ( array( 'cfg', 'cfgmap', 'dict', 'parser' ) as $table ) {
 323                                         $SQL = "GRANT SELECT ON pg_ts_$table TO $safeuser";
 324                                         $this->doQuery( $SQL );
 325                                 }
 326                                 print "OK</li>\n";
 327                         }
 328
 329                         // Setup the schema for this user if needed
 330                         $result = $this->schemaExists( $wgDBmwschema );
 331                         $safeschema = $this->addIdentifierQuotes( $wgDBmwschema );
 332                         if ( !$result ) {
 333                                 print '<li>Creating schema <b>' . htmlspecialchars( $wgDBmwschema ) . '</b> ...';
 334                                 $result = $this->doQuery( "CREATE SCHEMA $safeschema AUTHORIZATION $safeuser" );
 335                                 if ( !$result ) {
 336                                         print "<b>FAILED</b>.</li>\n";
 337                                         dieout( );
 338                                 }
 339                                 print "OK</li>\n";
 340                         } else {
 341                                 print "<li>Schema already exists, explicitly granting rights...\n";
 342                                 $safeschema2 = $this->addQuotes( $wgDBmwschema );
 343                                 $SQL = "SELECT 'GRANT ALL ON '||pg_catalog.quote_ident(relname)||' TO $safeuser;'\n".
 344                                         "FROM pg_catalog.pg_class p, pg_catalog.pg_namespace n\n".
 345                                         "WHERE relnamespace = n.oid AND n.nspname = $safeschema2\n".
 346                                         "AND p.relkind IN ('r','S','v')\n";
 347                                 $SQL .= "UNION\n";
 348                                 $SQL .= "SELECT 'GRANT ALL ON FUNCTION '||pg_catalog.quote_ident(proname)||'('||\n".
 349                                         "pg_catalog.oidvectortypes(p.proargtypes)||') TO $safeuser;'\n".
 350                                         "FROM pg_catalog.pg_proc p, pg_catalog.pg_namespace n\n".
 351                                         "WHERE p.pronamespace = n.oid AND n.nspname = $safeschema2";
 352                                 $res = $this->doQuery( $SQL );
 353                                 if ( !$res ) {
 354                                         print "<b>FAILED</b>. Could not set rights for the user.</li>\n";
 355                                         dieout( );
 356                                 }
 357                                 $this->doQuery( "SET search_path = $safeschema" );
 358                                 $rows = $this->numRows( $res );
 359                                 while ( $rows ) {
 360                                         $rows--;
 361                                         $this->doQuery( pg_fetch_result( $res, $rows, 0 ) );
 362                                 }
 363                                 print "OK</li>";
 364                         }
 365
 366                         // Install plpgsql if needed
 367                         $this->setup_plpgsql();
 368
 369                         return true; // Reconnect as regular user
 370
 371                 } // end superuser
 372
 373                 if ( !defined( 'POSTGRES_SEARCHPATH' ) ) {
 374
 375                         if ( $this->numeric_version < 8.3 ) {
 376                                 // Do we have the basic tsearch2 table?
 377                                 print '<li>Checking for tsearch2 in the schema "' . htmlspecialchars( $wgDBts2schema ) . '"...';
 378                                 if ( !$this->tableExists( 'pg_ts_dict', $wgDBts2schema ) ) {
 379                                         print '<b>FAILED</b>. Make sure tsearch2 is installed. See <a href="';
 380                                         print 'http://www.devx.com/opensource/Article/21674/0/page/2">this article</a>';
 381                                         print " for instructions.</li>\n";
 382                                         dieout( );
 383                                 }
 384                                 print "OK</li>\n";
 385
 386                                 // Does this user have the rights to the tsearch2 tables?
 387                                 $ctype = pg_fetch_result( $this->doQuery( 'SHOW lc_ctype' ), 0, 0 );
 388                                 print '<li>Checking tsearch2 permissions...';
 389                                 // Let's check all four, just to be safe
 390                                 error_reporting( 0 );
 391                                 $ts2tables = array( 'cfg', 'cfgmap', 'dict', 'parser' );
 392                                 $safetsschema = $this->addIdentifierQuotes( $wgDBts2schema );
 393                                 foreach ( $ts2tables as $tname ) {
 394                                         $SQL = "SELECT count(*) FROM $safetsschema.pg_ts_$tname";
 395                                         $res = $this->doQuery( $SQL );
 396                                         if ( !$res ) {
 397                                                 print "<b>FAILED</b> to access " . htmlspecialchars( "pg_ts_$tname" ) .
 398                                                         ". Make sure that the user \"". htmlspecialchars( $wgDBuser ) .
 399                                                         "\" has SELECT access to all four tsearch2 tables</li>\n";
 400                                                 dieout( );
 401                                         }
 402                                 }
 403                                 $SQL = "SELECT ts_name FROM $safetsschema.pg_ts_cfg WHERE locale = " . $this->addQuotes( $ctype ) ;
 404                                 $SQL .= " ORDER BY CASE WHEN ts_name <> 'default' THEN 1 ELSE 0 END";
 405                                 $res = $this->doQuery( $SQL );
 406                                 error_reporting( E_ALL );
 407                                 if ( !$res ) {
 408                                         print "<b>FAILED</b>. Could not determine the tsearch2 locale information</li>\n";
 409                                         dieout("</ul>");
 410                                 }
 411                                 print 'OK</li>';
 412
 413                                 // Will the current locale work? Can we force it to?
 414                                 print '<li>Verifying tsearch2 locale with ' . htmlspecialchars( $ctype ) . '...';
 415                                 $rows = $this->numRows( $res );
 416                                 $resetlocale = 0;
 417                                 if ( !$rows ) {
 418                                         print "<b>not found</b></li>\n";
 419                                         print '<li>Attempting to set default tsearch2 locale to "' . htmlspecialchars( $ctype ) . '"...';
 420                                         $resetlocale = 1;
 421                                 } else {
 422                                         $tsname = pg_fetch_result( $res, 0, 0 );
 423                                         if ( $tsname != 'default' ) {
 424                                                 print "<b>not set to default (" . htmlspecialchars( $tsname ) . ")</b>";
 425                                                 print "<li>Attempting to change tsearch2 default locale to \"" .
 426                                                         htmlspecialchars( $ctype ) . "\"...";
 427                                                 $resetlocale = 1;
 428                                         }
 429                                 }
 430                                 if ( $resetlocale ) {
 431                                         $SQL = "UPDATE $safetsschema.pg_ts_cfg SET locale = " . $this->addQuotes( $ctype ) . " WHERE ts_name = 'default'";
 432                                         $res = $this->doQuery( $SQL );
 433                                         if ( !$res ) {
 434                                                 print '<b>FAILED</b>. ';
 435                                                 print 'Please make sure that the locale in pg_ts_cfg for "default" is set to "' .
 436                                                         htmlspecialchars( $ctype ) . "\"</li>\n";
 437                                                 dieout( );
 438                                         }
 439                                         print 'OK</li>';
 440                                 }
 441
 442                                 // Final test: try out a simple tsearch2 query
 443                                 $SQL = "SELECT $safetsschema.to_tsvector('default','MediaWiki tsearch2 testing')";
 444                                 $res = $this->doQuery( $SQL );
 445                                 if ( !$res ) {
 446                                         print '<b>FAILED</b>. Specifically, "' . htmlspecialchars( $SQL ) . '" did not work.</li>';
 447                                         dieout( );
 448                                 }
 449                                 print 'OK</li>';
 450                         }
 451
 452                         // Install plpgsql if needed
 453                         $this->setup_plpgsql();
 454
 455                         // Does the schema already exist? Who owns it?
 456                         $result = $this->schemaExists( $wgDBmwschema );
 457                         if ( !$result ) {
 458                                 print '<li>Creating schema <b>' . htmlspecialchars( $wgDBmwschema ) . '</b> ...';
 459                                 error_reporting( 0 );
 460                                 $safeschema = $this->addIdentifierQuotes( $wgDBmwschema );
 461                                 $result = $this->doQuery( "CREATE SCHEMA $safeschema" );
 462                                 error_reporting( E_ALL );
 463                                 if ( !$result ) {
 464                                         print '<b>FAILED</b>. The user "' . htmlspecialchars( $wgDBuser ) .
 465                                                 '" must be able to access the schema. '.
 466                                                 'You can try making them the owner of the database, or try creating the schema with a '.
 467                                                 'different user, and then grant access to the "' .
 468                                                 htmlspecialchars( $wgDBuser ) . "\" user.</li>\n";
 469                                         dieout( );
 470                                 }
 471                                 print "OK</li>\n";
 472                         } elseif ( $result != $wgDBuser ) {
 473                                 print '<li>Schema "' . htmlspecialchars( $wgDBmwschema ) . '" exists but is not owned by "' .
 474                                         htmlspecialchars( $wgDBuser ) . "\". Not ideal.</li>\n";
 475                         } else {
 476                                 print '<li>Schema "' . htmlspecialchars( $wgDBmwschema ) . '" exists and is owned by "' .
 477                                         htmlspecialchars( $wgDBuser ) . "\". Excellent.</li>\n";
 478                         }
 479
 480                         // Always return GMT time to accomodate the existing integer-based timestamp assumption
 481                         print "<li>Setting the timezone to GMT for user \"" . htmlspecialchars( $wgDBuser ) . '" ...';
 482                         $SQL = "ALTER USER $safeuser SET timezone = 'GMT'";
 483                         $result = pg_query( $this->mConn, $SQL );
 484                         if ( !$result ) {
 485                                 print "<b>FAILED</b>.</li>\n";
 486                                 dieout( );
 487                         }
 488                         print "OK</li>\n";
 489                         // Set for the rest of this session
 490                         $SQL = "SET timezone = 'GMT'";
 491                         $result = pg_query( $this->mConn, $SQL );
 492                         if ( !$result ) {
 493                                 print "<li>Failed to set timezone</li>\n";
 494                                 dieout( );
 495                         }
 496
 497                         print '<li>Setting the datestyle to ISO, YMD for user "' . htmlspecialchars( $wgDBuser ) . '" ...';
 498                         $SQL = "ALTER USER $safeuser SET datestyle = 'ISO, YMD'";
 499                         $result = pg_query( $this->mConn, $SQL );
 500                         if ( !$result ) {
 501                                 print "<b>FAILED</b>.</li>\n";
 502                                 dieout( );
 503                         }
 504                         print "OK</li>\n";
 505                         // Set for the rest of this session
 506                         $SQL = "SET datestyle = 'ISO, YMD'";
 507                         $result = pg_query( $this->mConn, $SQL );
 508                         if ( !$result ) {
 509                                 print "<li>Failed to set datestyle</li>\n";
 510                                 dieout( );
 511                         }
 512
 513                         // Fix up the search paths if needed
 514                         print '<li>Setting the search path for user "' . htmlspecialchars( $wgDBuser ) . '" ...';
 515                         $path = $this->addIdentifierQuotes( $wgDBmwschema );
 516                         if ( $wgDBts2schema !== $wgDBmwschema ) {
 517                                 $path .= ', '. $this->addIdentifierQuotes( $wgDBts2schema );
 518                         }
 519                         if ( $wgDBmwschema !== 'public' && $wgDBts2schema !== 'public' ) {
 520                                 $path .= ', public';
 521                         }
 522                         $SQL = "ALTER USER $safeuser SET search_path = $path";
 523                         $result = pg_query( $this->mConn, $SQL );
 524                         if ( !$result ) {
 525                                 print "<b>FAILED</b>.</li>\n";
 526                                 dieout( );
 527                         }
 528                         print "OK</li>\n";
 529                         // Set for the rest of this session
 530                         $SQL = "SET search_path = $path";
 531                         $result = pg_query( $this->mConn, $SQL );
 532                         if ( !$result ) {
 533                                 print "<li>Failed to set search_path</li>\n";
 534                                 dieout( );
 535                         }
 536                         define( 'POSTGRES_SEARCHPATH', $path );
 537                 }
 538         }
 539
 540         /**
 541          * Closes a database connection, if it is open
 542          * Returns success, true if already closed
 543          */
 544         function close() {
 545                 $this->mOpened = false;
 546                 if ( $this->mConn ) {
 547                         return pg_close( $this->mConn );
 548                 } else {
 549                         return true;
 550                 }
 551         }
 552
 553         function doQuery( $sql ) {
 554                 if ( function_exists( 'mb_convert_encoding' ) ) {
 555                         $sql = mb_convert_encoding( $sql, 'UTF-8' );
 556                 }
 557                 $this->mLastResult = pg_query( $this->mConn, $sql );
 558                 $this->mAffectedRows = null; // use pg_affected_rows(mLastResult)
 559                 return $this->mLastResult;
 560         }
 561
 562         function queryIgnore( $sql, $fname = 'DatabasePostgres::queryIgnore' ) {
 563                 return $this->query( $sql, $fname, true );
 564         }
 565
 566         function freeResult( $res ) {
 567                 if ( $res instanceof ResultWrapper ) {
 568                         $res = $res->result;
 569                 }
 570                 if ( !@pg_free_result( $res ) ) {
 571                         throw new DBUnexpectedError( $this, "Unable to free Postgres result\n" );
 572                 }
 573         }
 574
 575         function fetchObject( $res ) {
 576                 if ( $res instanceof ResultWrapper ) {
 577                         $res = $res->result;
 578                 }
 579                 @$row = pg_fetch_object( $res );
 580                 # FIXME: HACK HACK HACK HACK debug
 581
 582                 # TODO:
 583                 # hashar : not sure if the following test really trigger if the object
 584                 #          fetching failed.
 585                 if( pg_last_error( $this->mConn ) ) {
 586                         throw new DBUnexpectedError( $this, 'SQL error: ' . htmlspecialchars( pg_last_error( $this->mConn ) ) );
 587                 }
 588                 return $row;
 589         }
 590
 591         function fetchRow( $res ) {
 592                 if ( $res instanceof ResultWrapper ) {
 593                         $res = $res->result;
 594                 }
 595                 @$row = pg_fetch_array( $res );
 596                 if( pg_last_error( $this->mConn ) ) {
 597                         throw new DBUnexpectedError( $this, 'SQL error: ' . htmlspecialchars( pg_last_error( $this->mConn ) ) );
 598                 }
 599                 return $row;
 600         }
 601
 602         function numRows( $res ) {
 603                 if ( $res instanceof ResultWrapper ) {
 604                         $res = $res->result;
 605                 }
 606                 @$n = pg_num_rows( $res );
 607                 if( pg_last_error( $this->mConn ) ) {
 608                         throw new DBUnexpectedError( $this, 'SQL error: ' . htmlspecialchars( pg_last_error( $this->mConn ) ) );
 609                 }
 610                 return $n;
 611         }
 612
 613         function numFields( $res ) {
 614                 if ( $res instanceof ResultWrapper ) {
 615                         $res = $res->result;
 616                 }
 617                 return pg_num_fields( $res );
 618         }
 619
 620         function fieldName( $res, $n ) {
 621                 if ( $res instanceof ResultWrapper ) {
 622                         $res = $res->result;
 623                 }
 624                 return pg_field_name( $res, $n );
 625         }
 626
 627         /**
 628          * This must be called after nextSequenceVal
 629          */
 630         function insertId() {
 631                 return $this->mInsertId;
 632         }
 633
 634         function dataSeek( $res, $row ) {
 635                 if ( $res instanceof ResultWrapper ) {
 636                         $res = $res->result;
 637                 }
 638                 return pg_result_seek( $res, $row );
 639         }
 640
 641         function lastError() {
 642                 if ( $this->mConn ) {
 643                         return pg_last_error();
 644                 } else {
 645                         return 'No database connection';
 646                 }
 647         }
 648         function lastErrno() {
 649                 return pg_last_error() ? 1 : 0;
 650         }
 651
 652         function affectedRows() {
 653                 if ( !is_null( $this->mAffectedRows ) ) {
 654                         // Forced result for simulated queries
 655                         return $this->mAffectedRows;
 656                 }
 657                 if( empty( $this->mLastResult ) ) {
 658                         return 0;
 659                 }
 660                 return pg_affected_rows( $this->mLastResult );
 661         }
 662
 663         /**
 664          * Estimate rows in dataset
 665          * Returns estimated count, based on EXPLAIN output
 666          * This is not necessarily an accurate estimate, so use sparingly
 667          * Returns -1 if count cannot be found
 668          * Takes same arguments as Database::select()
 669          */
 670         function estimateRowCount( $table, $vars = '*', $conds='', $fname = 'DatabasePostgres::estimateRowCount', $options = array() ) {
 671                 $options['EXPLAIN'] = true;
 672                 $res = $this->select( $table, $vars, $conds, $fname, $options );
 673                 $rows = -1;
 674                 if ( $res ) {
 675                         $row = $this->fetchRow( $res );
 676                         $count = array();
 677                         if( preg_match( '/rows=(\d+)/', $row[0], $count ) ) {
 678                                 $rows = $count[1];
 679                         }
 680                 }
 681                 return $rows;
 682         }
 683
 684         /**
 685          * Returns information about an index
 686          * If errors are explicitly ignored, returns NULL on failure
 687          */
 688         function indexInfo( $table, $index, $fname = 'DatabasePostgres::indexInfo' ) {
 689                 $sql = "SELECT indexname FROM pg_indexes WHERE tablename='$table'";
 690                 $res = $this->query( $sql, $fname );
 691                 if ( !$res ) {
 692                         return null;
 693                 }
 694                 foreach ( $res as $row ) {
 695                         if ( $row->indexname == $this->indexName( $index ) ) {
 696                                 return $row;
 697                         }
 698                 }
 699                 return false;
 700         }
 701
 702         function indexUnique( $table, $index, $fname = 'DatabasePostgres::indexUnique' ) {
 703                 $sql = "SELECT indexname FROM pg_indexes WHERE tablename='{$table}'".
 704                         " AND indexdef LIKE 'CREATE UNIQUE%(" .
 705                         $this->strencode( $this->indexName( $index ) ) .
 706                         ")'";
 707                 $res = $this->query( $sql, $fname );
 708                 if ( !$res ) {
 709                         return null;
 710                 }
 711                 foreach ( $res as $row ) {
 712                         return true;
 713                 }
 714                 return false;
 715         }
 716
 717         /**
 718          * INSERT wrapper, inserts an array into a table
 719          *
 720          * $args may be a single associative array, or an array of these with numeric keys,
 721          * for multi-row insert (Postgres version 8.2 and above only).
 722          *
 723          * @param $table   String: Name of the table to insert to.
 724          * @param $args    Array: Items to insert into the table.
 725          * @param $fname   String: Name of the function, for profiling
 726          * @param $options String or Array. Valid options: IGNORE
 727          *
 728          * @return bool Success of insert operation. IGNORE always returns true.
 729          */
 730         function insert( $table, $args, $fname = 'DatabasePostgres::insert', $options = array() ) {
 731                 if ( !count( $args ) ) {
 732                         return true;
 733                 }
 734
 735                 $table = $this->tableName( $table );
 736                 if (! isset( $this->numeric_version ) ) {
 737                         $this->getServerVersion();
 738                 }
 739
 740                 if ( !is_array( $options ) ) {
 741                         $options = array( $options );
 742                 }
 743
 744                 if ( isset( $args[0] ) && is_array( $args[0] ) ) {
 745                         $multi = true;
 746                         $keys = array_keys( $args[0] );
 747                 } else {
 748                         $multi = false;
 749                         $keys = array_keys( $args );
 750                 }
 751
 752                 // If IGNORE is set, we use savepoints to emulate mysql's behavior
 753                 $ignore = in_array( 'IGNORE', $options ) ? 'mw' : '';
 754
 755                 // If we are not in a transaction, we need to be for savepoint trickery
 756                 $didbegin = 0;
 757                 if ( $ignore ) {
 758                         if ( !$this->mTrxLevel ) {
 759                                 $this->begin();
 760                                 $didbegin = 1;
 761                         }
 762                         $olde = error_reporting( 0 );
 763                         // For future use, we may want to track the number of actual inserts
 764                         // Right now, insert (all writes) simply return true/false
 765                         $numrowsinserted = 0;
 766                 }
 767
 768                 $sql = "INSERT INTO $table (" . implode( ',', $keys ) . ') VALUES ';
 769
 770                 if ( $multi ) {
 771                         if ( $this->numeric_version >= 8.2 && !$ignore ) {
 772                                 $first = true;
 773                                 foreach ( $args as $row ) {
 774                                         if ( $first ) {
 775                                                 $first = false;
 776                                         } else {
 777                                                 $sql .= ',';
 778                                         }
 779                                         $sql .= '(' . $this->makeList( $row ) . ')';
 780                                 }
 781                                 $res = (bool)$this->query( $sql, $fname, $ignore );
 782                         } else {
 783                                 $res = true;
 784                                 $origsql = $sql;
 785                                 foreach ( $args as $row ) {
 786                                         $tempsql = $origsql;
 787                                         $tempsql .= '(' . $this->makeList( $row ) . ')';
 788
 789                                         if ( $ignore ) {
 790                                                 pg_query( $this->mConn, "SAVEPOINT $ignore" );
 791                                         }
 792
 793                                         $tempres = (bool)$this->query( $tempsql, $fname, $ignore );
 794
 795                                         if ( $ignore ) {
 796                                                 $bar = pg_last_error();
 797                                                 if ( $bar != false ) {
 798                                                         pg_query( $this->mConn, "ROLLBACK TO $ignore" );
 799                                                 } else {
 800                                                         pg_query( $this->mConn, "RELEASE $ignore" );
 801                                                         $numrowsinserted++;
 802                                                 }
 803                                         }
 804
 805                                         // If any of them fail, we fail overall for this function call
 806                                         // Note that this will be ignored if IGNORE is set
 807                                         if ( !$tempres ) {
 808                                                 $res = false;
 809                                         }
 810                                 }
 811                         }
 812                 } else {
 813                         // Not multi, just a lone insert
 814                         if ( $ignore ) {
 815                                 pg_query($this->mConn, "SAVEPOINT $ignore");
 816                         }
 817
 818                         $sql .= '(' . $this->makeList( $args ) . ')';
 819                         $res = (bool)$this->query( $sql, $fname, $ignore );
 820                         if ( $ignore ) {
 821                                 $bar = pg_last_error();
 822                                 if ( $bar != false ) {
 823                                         pg_query( $this->mConn, "ROLLBACK TO $ignore" );
 824                                 } else {
 825                                         pg_query( $this->mConn, "RELEASE $ignore" );
 826                                         $numrowsinserted++;
 827                                 }
 828                         }
 829                 }
 830                 if ( $ignore ) {
 831                         $olde = error_reporting( $olde );
 832                         if ( $didbegin ) {
 833                                 $this->commit();
 834                         }
 835
 836                         // Set the affected row count for the whole operation
 837                         $this->mAffectedRows = $numrowsinserted;
 838
 839                         // IGNORE always returns true
 840                         return true;
 841                 }
 842
 843                 return $res;
 844         }
 845
 846         /**
 847          * INSERT SELECT wrapper
 848          * $varMap must be an associative array of the form array( 'dest1' => 'source1', ...)
 849          * Source items may be literals rather then field names, but strings should be quoted with Database::addQuotes()
 850          * $conds may be "*" to copy the whole table
 851          * srcTable may be an array of tables.
 852          * @todo FIXME: implement this a little better (seperate select/insert)?
 853          */
 854         function insertSelect( $destTable, $srcTable, $varMap, $conds, $fname = 'DatabasePostgres::insertSelect',
 855                 $insertOptions = array(), $selectOptions = array() )
 856         {
 857                 $destTable = $this->tableName( $destTable );
 858
 859                 // If IGNORE is set, we use savepoints to emulate mysql's behavior
 860                 $ignore = in_array( 'IGNORE', $insertOptions ) ? 'mw' : '';
 861
 862                 if( is_array( $insertOptions ) ) {
 863                         $insertOptions = implode( ' ', $insertOptions );
 864                 }
 865                 if( !is_array( $selectOptions ) ) {
 866                         $selectOptions = array( $selectOptions );
 867                 }
 868                 list( $startOpts, $useIndex, $tailOpts ) = $this->makeSelectOptions( $selectOptions );
 869                 if( is_array( $srcTable ) ) {
 870                         $srcTable = implode( ',', array_map( array( &$this, 'tableName' ), $srcTable ) );
 871                 } else {
 872                         $srcTable = $this->tableName( $srcTable );
 873                 }
 874
 875                 // If we are not in a transaction, we need to be for savepoint trickery
 876                 $didbegin = 0;
 877                 if ( $ignore ) {
 878                         if( !$this->mTrxLevel ) {
 879                                 $this->begin();
 880                                 $didbegin = 1;
 881                         }
 882                         $olde = error_reporting( 0 );
 883                         $numrowsinserted = 0;
 884                         pg_query( $this->mConn, "SAVEPOINT $ignore");
 885                 }
 886
 887                 $sql = "INSERT INTO $destTable (" . implode( ',', array_keys( $varMap ) ) . ')' .
 888                                 " SELECT $startOpts " . implode( ',', $varMap ) .
 889                                 " FROM $srcTable $useIndex";
 890
 891                 if ( $conds != '*' ) {
 892                         $sql .= ' WHERE ' . $this->makeList( $conds, LIST_AND );
 893                 }
 894
 895                 $sql .= " $tailOpts";
 896
 897                 $res = (bool)$this->query( $sql, $fname, $ignore );
 898                 if( $ignore ) {
 899                         $bar = pg_last_error();
 900                         if( $bar != false ) {
 901                                 pg_query( $this->mConn, "ROLLBACK TO $ignore" );
 902                         } else {
 903                                 pg_query( $this->mConn, "RELEASE $ignore" );
 904                                 $numrowsinserted++;
 905                         }
 906                         $olde = error_reporting( $olde );
 907                         if( $didbegin ) {
 908                                 $this->commit();
 909                         }
 910
 911                         // Set the affected row count for the whole operation
 912                         $this->mAffectedRows = $numrowsinserted;
 913
 914                         // IGNORE always returns true
 915                         return true;
 916                 }
 917
 918                 return $res;
 919         }
 920
 921         function tableName( $name ) {
 922                 # Replace reserved words with better ones
 923                 switch( $name ) {
 924                         case 'user':
 925                                 return 'mwuser';
 926                         case 'text':
 927                                 return 'pagecontent';
 928                         default:
 929                                 return $name;
 930                 }
 931         }
 932
 933         /**
 934          * Return the next in a sequence, save the value for retrieval via insertId()
 935          */
 936         function nextSequenceValue( $seqName ) {
 937                 $safeseq = str_replace( "'", "''", $seqName );
 938                 $res = $this->query( "SELECT nextval('$safeseq')" );
 939                 $row = $this->fetchRow( $res );
 940                 $this->mInsertId = $row[0];
 941                 return $this->mInsertId;
 942         }
 943
 944         /**
 945          * Return the current value of a sequence. Assumes it has been nextval'ed in this session.
 946          */
 947         function currentSequenceValue( $seqName ) {
 948                 $safeseq = str_replace( "'", "''", $seqName );
 949                 $res = $this->query( "SELECT currval('$safeseq')" );
 950                 $row = $this->fetchRow( $res );
 951                 $currval = $row[0];
 952                 return $currval;
 953         }
 954
 955         /**
 956          * REPLACE query wrapper
 957          * Postgres simulates this with a DELETE followed by INSERT
 958          * $row is the row to insert, an associative array
 959          * $uniqueIndexes is an array of indexes. Each element may be either a
 960          * field name or an array of field names
 961          *
 962          * It may be more efficient to leave off unique indexes which are unlikely to collide.
 963          * However if you do this, you run the risk of encountering errors which wouldn't have
 964          * occurred in MySQL
 965          */
 966         function replace( $table, $uniqueIndexes, $rows, $fname = 'DatabasePostgres::replace' ) {
 967                 $table = $this->tableName( $table );
 968
 969                 if ( count( $rows ) == 0 ) {
 970                         return;
 971                 }
 972
 973                 # Single row case
 974                 if ( !is_array( reset( $rows ) ) ) {
 975                         $rows = array( $rows );
 976                 }
 977
 978                 foreach( $rows as $row ) {
 979                         # Delete rows which collide
 980                         if ( $uniqueIndexes ) {
 981                                 $sql = "DELETE FROM $table WHERE ";
 982                                 $first = true;
 983                                 foreach ( $uniqueIndexes as $index ) {
 984                                         if ( $first ) {
 985                                                 $first = false;
 986                                                 $sql .= '(';
 987                                         } else {
 988                                                 $sql .= ') OR (';
 989                                         }
 990                                         if ( is_array( $index ) ) {
 991                                                 $first2 = true;
 992                                                 foreach ( $index as $col ) {
 993                                                         if ( $first2 ) {
 994                                                                 $first2 = false;
 995                                                         } else {
 996                                                                 $sql .= ' AND ';
 997                                                         }
 998                                                         $sql .= $col.'=' . $this->addQuotes( $row[$col] );
 999                                                 }
1000                                         } else {
1001                                                 $sql .= $index.'=' . $this->addQuotes( $row[$index] );
1002                                         }
1003                                 }
1004                                 $sql .= ')';
1005                                 $this->query( $sql, $fname );
1006                         }
1007
1008                         # Now insert the row
1009                         $sql = "INSERT INTO $table (" . $this->makeList( array_keys( $row ), LIST_NAMES ) .') VALUES (' .
1010                                 $this->makeList( $row, LIST_COMMA ) . ')';
1011                         $this->query( $sql, $fname );
1012                 }
1013         }
1014
1015         # DELETE where the condition is a join
1016         function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds, $fname = 'DatabasePostgres::deleteJoin' ) {
1017                 if ( !$conds ) {
1018                         throw new DBUnexpectedError( $this, 'DatabasePostgres::deleteJoin() called with empty $conds' );
1019                 }
1020
1021                 $delTable = $this->tableName( $delTable );
1022                 $joinTable = $this->tableName( $joinTable );
1023                 $sql = "DELETE FROM $delTable WHERE $delVar IN (SELECT $joinVar FROM $joinTable ";
1024                 if ( $conds != '*' ) {
1025                         $sql .= 'WHERE ' . $this->makeList( $conds, LIST_AND );
1026                 }
1027                 $sql .= ')';
1028
1029                 $this->query( $sql, $fname );
1030         }
1031
1032         # Returns the size of a text field, or -1 for "unlimited"
1033         function textFieldSize( $table, $field ) {
1034                 $table = $this->tableName( $table );
1035                 $sql = "SELECT t.typname as ftype,a.atttypmod as size
1036                         FROM pg_class c, pg_attribute a, pg_type t
1037                         WHERE relname='$table' AND a.attrelid=c.oid AND
1038                                 a.atttypid=t.oid and a.attname='$field'";
1039                 $res =$this->query( $sql );
1040                 $row = $this->fetchObject( $res );
1041                 if ( $row->ftype == 'varchar' ) {
1042                         $size = $row->size - 4;
1043                 } else {
1044                         $size = $row->size;
1045                 }
1046                 return $size;
1047         }
1048
1049         function limitResult( $sql, $limit, $offset = false ) {
1050                 return "$sql LIMIT $limit " . ( is_numeric( $offset ) ? " OFFSET {$offset} " : '' );
1051         }
1052
1053         function wasDeadlock() {
1054                 return $this->lastErrno() == '40P01';
1055         }
1056
1057         function duplicateTableStructure( $oldName, $newName, $temporary = false, $fname = 'DatabasePostgres::duplicateTableStructure' ) {
1058                 return $this->query( 'CREATE ' . ( $temporary ? 'TEMPORARY ' : '' ) . " TABLE $newName (LIKE $oldName INCLUDING DEFAULTS)", $fname );
1059         }
1060
1061         function timestamp( $ts = 0 ) {
1062                 return wfTimestamp( TS_POSTGRES, $ts );
1063         }
1064
1065         /**
1066          * Return aggregated value function call
1067          */
1068         function aggregateValue( $valuedata, $valuename = 'value' ) {
1069                 return $valuedata;
1070         }
1071
1072         function reportQueryError( $error, $errno, $sql, $fname, $tempIgnore = false ) {
1073                 // Ignore errors during error handling to avoid infinite recursion
1074                 $ignore = $this->ignoreErrors( true );
1075                 $this->mErrorCount++;
1076
1077                 if ( $ignore || $tempIgnore ) {
1078                         wfDebug( "SQL ERROR (ignored): $error\n" );
1079                         $this->ignoreErrors( $ignore );
1080                 } else {
1081                         $message = "A database error has occurred.  Did you forget to run maintenance/update.php after upgrading?  See: http://www.mediawiki.org/wiki/Manual:Upgrading#Run_the_update_script\n" .
1082                                 "Query: $sql\n" .
1083                                 "Function: $fname\n" .
1084                                 "Error: $errno $error\n";
1085                         throw new DBUnexpectedError( $this, $message );
1086                 }
1087         }
1088
1089         /**
1090          * @return string wikitext of a link to the server software's web site
1091          */
1092         public static function getSoftwareLink() {
1093                 return '[http://www.postgresql.org/ PostgreSQL]';
1094         }
1095
1096         /**
1097          * @return string Version information from the database
1098          */
1099         function getServerVersion() {
1100                 if ( !isset( $this->numeric_version ) ) {
1101                         $versionInfo = pg_version( $this->mConn );
1102                         if ( version_compare( $versionInfo['client'], '7.4.0', 'lt' ) ) {
1103                                 // Old client, abort install
1104                                 $this->numeric_version = '7.3 or earlier';
1105                         } elseif ( isset( $versionInfo['server'] ) ) {
1106                                 // Normal client
1107                                 $this->numeric_version = $versionInfo['server'];
1108                         } else {
1109                                 // Bug 16937: broken pgsql extension from PHP<5.3
1110                                 $this->numeric_version = pg_parameter_status( $this->mConn, 'server_version' );
1111                         }
1112                 }
1113                 return $this->numeric_version;
1114         }
1115
1116         /**
1117          * Query whether a given relation exists (in the given schema, or the
1118          * default mw one if not given)
1119          */
1120         function relationExists( $table, $types, $schema = false ) {
1121                 global $wgDBmwschema;
1122                 if ( !is_array( $types ) ) {
1123                         $types = array( $types );
1124                 }
1125                 if ( !$schema ) {
1126                         $schema = $wgDBmwschema;
1127                 }
1128                 $etable = $this->addQuotes( $table );
1129                 $eschema = $this->addQuotes( $schema );
1130                 $SQL = "SELECT 1 FROM pg_catalog.pg_class c, pg_catalog.pg_namespace n "
1131                         . "WHERE c.relnamespace = n.oid AND c.relname = $etable AND n.nspname = $eschema "
1132                         . "AND c.relkind IN ('" . implode( "','", $types ) . "')";
1133                 $res = $this->query( $SQL );
1134                 $count = $res ? $res->numRows() : 0;
1135                 return (bool)$count;
1136         }
1137
1138         /**
1139          * For backward compatibility, this function checks both tables and
1140          * views.
1141          */
1142         function tableExists( $table, $schema = false ) {
1143                 return $this->relationExists( $table, array( 'r', 'v' ), $schema );
1144         }
1145
1146         function sequenceExists( $sequence, $schema = false ) {
1147                 return $this->relationExists( $sequence, 'S', $schema );
1148         }
1149
1150         function triggerExists( $table, $trigger ) {
1151                 global $wgDBmwschema;
1152
1153                 $q = <<<SQL
1154         SELECT 1 FROM pg_class, pg_namespace, pg_trigger
1155                 WHERE relnamespace=pg_namespace.oid AND relkind='r'
1156                       AND tgrelid=pg_class.oid
1157                       AND nspname=%s AND relname=%s AND tgname=%s
1158 SQL;
1159                 $res = $this->query(
1160                         sprintf(
1161                                 $q,
1162                                 $this->addQuotes( $wgDBmwschema ),
1163                                 $this->addQuotes( $table ),
1164                                 $this->addQuotes( $trigger )
1165                         )
1166                 );
1167                 if ( !$res ) {
1168                         return null;
1169                 }
1170                 $rows = $res->numRows();
1171                 return $rows;
1172         }
1173
1174         function ruleExists( $table, $rule ) {
1175                 global $wgDBmwschema;
1176                 $exists = $this->selectField( 'pg_rules', 'rulename',
1177                         array(
1178                                 'rulename' => $rule,
1179                                 'tablename' => $table,
1180                                 'schemaname' => $wgDBmwschema
1181                         )
1182                 );
1183                 return $exists === $rule;
1184         }
1185
1186         function constraintExists( $table, $constraint ) {
1187                 global $wgDBmwschema;
1188                 $SQL = sprintf( "SELECT 1 FROM information_schema.table_constraints ".
1189                            "WHERE constraint_schema = %s AND table_name = %s AND constraint_name = %s",
1190                         $this->addQuotes( $wgDBmwschema ),
1191                         $this->addQuotes( $table ),
1192                         $this->addQuotes( $constraint )
1193                 );
1194                 $res = $this->query( $SQL );
1195                 if ( !$res ) {
1196                         return null;
1197                 }
1198                 $rows = $res->numRows();
1199                 return $rows;
1200         }
1201
1202         /**
1203          * Query whether a given schema exists. Returns the name of the owner
1204          */
1205         function schemaExists( $schema ) {
1206                 $eschema = str_replace( "'", "''", $schema );
1207                 $SQL = "SELECT rolname FROM pg_catalog.pg_namespace n, pg_catalog.pg_roles r "
1208                                 ."WHERE n.nspowner=r.oid AND n.nspname = '$eschema'";
1209                 $res = $this->query( $SQL );
1210                 if ( $res && $res->numRows() ) {
1211                         $row = $res->fetchObject();
1212                         $owner = $row->rolname;
1213                 } else {
1214                         $owner = false;
1215                 }
1216                 return $owner;
1217         }
1218
1219         function fieldInfo( $table, $field ) {
1220                 return PostgresField::fromText( $this, $table, $field );
1221         }
1222
1223         /**
1224          * pg_field_type() wrapper
1225          */
1226         function fieldType( $res, $index ) {
1227                 if ( $res instanceof ResultWrapper ) {
1228                         $res = $res->result;
1229                 }
1230                 return pg_field_type( $res, $index );
1231         }
1232
1233         /* Not even sure why this is used in the main codebase... */
1234         function limitResultForUpdate( $sql, $num ) {
1235                 return $sql;
1236         }
1237
1238         function encodeBlob( $b ) {
1239                 return new Blob( pg_escape_bytea( $this->mConn, $b ) );
1240         }
1241
1242         function decodeBlob( $b ) {
1243                 if ( $b instanceof Blob ) {
1244                         $b = $b->fetch();
1245                 }
1246                 return pg_unescape_bytea( $b );
1247         }
1248
1249         function strencode( $s ) { # Should not be called by us
1250                 return pg_escape_string( $this->mConn, $s );
1251         }
1252
1253         function addQuotes( $s ) {
1254                 if ( is_null( $s ) ) {
1255                         return 'NULL';
1256                 } elseif ( is_bool( $s ) ) {
1257                         return intval( $s );
1258                 } elseif ( $s instanceof Blob ) {
1259                         return "'" . $s->fetch( $s ) . "'";
1260                 }
1261                 return "'" . pg_escape_string( $this->mConn, $s ) . "'";
1262         }
1263
1264         /**
1265          * Postgres specific version of replaceVars.
1266          * Calls the parent version in Database.php
1267          *
1268          * @private
1269          *
1270          * @param $ins String: SQL string, read from a stream (usually tables.sql)
1271          *
1272          * @return string SQL string
1273          */
1274         protected function replaceVars( $ins ) {
1275                 $ins = parent::replaceVars( $ins );
1276
1277                 if ( $this->numeric_version >= 8.3 ) {
1278                         // Thanks for not providing backwards-compatibility, 8.3
1279                         $ins = preg_replace( "/to_tsvector\s*\(\s*'default'\s*,/", 'to_tsvector(', $ins );
1280                 }
1281
1282                 if ( $this->numeric_version <= 8.1 ) { // Our minimum version
1283                         $ins = str_replace( 'USING gin', 'USING gist', $ins );
1284                 }
1285
1286                 return $ins;
1287         }
1288
1289         /**
1290          * Various select options
1291          *
1292          * @private
1293          *
1294          * @param $options Array: an associative array of options to be turned into
1295          *              an SQL query, valid keys are listed in the function.
1296          * @return array
1297          */
1298         function makeSelectOptions( $options ) {
1299                 $preLimitTail = $postLimitTail = '';
1300                 $startOpts = $useIndex = '';
1301
1302                 $noKeyOptions = array();
1303                 foreach ( $options as $key => $option ) {
1304                         if ( is_numeric( $key ) ) {
1305                                 $noKeyOptions[$option] = true;
1306                         }
1307                 }
1308
1309                 if ( isset( $options['GROUP BY'] ) ) {
1310                         $preLimitTail .= ' GROUP BY ' . $options['GROUP BY'];
1311                 }
1312                 if ( isset( $options['HAVING'] ) ) {
1313                         $preLimitTail .= " HAVING {$options['HAVING']}";
1314                 }
1315                 if ( isset( $options['ORDER BY'] ) ) {
1316                         $preLimitTail .= ' ORDER BY ' . $options['ORDER BY'];
1317                 }
1318
1319                 //if ( isset( $options['LIMIT'] ) ) {
1320                 //      $tailOpts .= $this->limitResult( '', $options['LIMIT'],
1321                 //              isset( $options['OFFSET'] ) ? $options['OFFSET']
1322                 //              : false );
1323                 //}
1324
1325                 if ( isset( $noKeyOptions['FOR UPDATE'] ) ) {
1326                         $postLimitTail .= ' FOR UPDATE';
1327                 }
1328                 if ( isset( $noKeyOptions['LOCK IN SHARE MODE'] ) ) {
1329                         $postLimitTail .= ' LOCK IN SHARE MODE';
1330                 }
1331                 if ( isset( $noKeyOptions['DISTINCT'] ) || isset( $noKeyOptions['DISTINCTROW'] ) ) {
1332                         $startOpts .= 'DISTINCT';
1333                 }
1334
1335                 return array( $startOpts, $useIndex, $preLimitTail, $postLimitTail );
1336         }
1337
1338         function setFakeMaster( $enabled = true ) {}
1339
1340         function getDBname() {
1341                 return $this->mDBname;
1342         }
1343
1344         function getServer() {
1345                 return $this->mServer;
1346         }
1347
1348         function buildConcat( $stringList ) {
1349                 return implode( ' || ', $stringList );
1350         }
1351
1352         public function getSearchEngine() {
1353                 return 'SearchPostgres';
1354         }
1355 } // end DatabasePostgres class