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