includes/DatabasePostgres.php

   1 <?php
   2
   3 /**
   4  * This is the Postgres database abstraction layer.
   5  *
   6  * As it includes more generic version for DB functions,
   7  * than MySQL ones, some of them should be moved to parent
   8  * Database class.
   9  *
  10  * @package MediaWiki
  11  */
  12
  13 class DatabasePostgres extends Database {
  14         var $mInsertId = NULL;
  15         var $mLastResult = NULL;
  16         var $numeric_version = NULL;
  17
  18         function DatabasePostgres($server = false, $user = false, $password = false, $dbName = false,
  19                 $failFunction = false, $flags = 0 )
  20         {
  21
  22                 global $wgOut;
  23                 # Can't get a reference if it hasn't been set yet
  24                 if ( !isset( $wgOut ) ) {
  25                         $wgOut = NULL;
  26                 }
  27                 $this->mOut =& $wgOut;
  28                 $this->mFailFunction = $failFunction;
  29                 $this->mCascadingDeletes = true;
  30                 $this->mCleanupTriggers = true;
  31                 $this->mStrictIPs = true;
  32                 $this->mFlags = $flags;
  33                 $this->open( $server, $user, $password, $dbName);
  34
  35         }
  36
  37         function realTimestamps() {
  38                 return true;
  39         }
  40
  41         function implicitGroupby() {
  42                 return false;
  43         }
  44
  45         static function newFromParams( $server = false, $user = false, $password = false, $dbName = false,
  46                 $failFunction = false, $flags = 0)
  47         {
  48                 return new DatabasePostgres( $server, $user, $password, $dbName, $failFunction, $flags );
  49         }
  50
  51         /**
  52          * Usually aborts on failure
  53          * If the failFunction is set to a non-zero integer, returns success
  54          */
  55         function open( $server, $user, $password, $dbName ) {
  56                 # Test for Postgres support, to avoid suppressed fatal error
  57                 if ( !function_exists( 'pg_connect' ) ) {
  58                         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" );
  59                 }
  60
  61
  62                 global $wgDBport;
  63
  64                 $this->close();
  65                 $this->mServer = $server;
  66                 $port = $wgDBport;
  67                 $this->mUser = $user;
  68                 $this->mPassword = $password;
  69                 $this->mDBname = $dbName;
  70
  71                 $hstring="";
  72                 if ($server!=false && $server!="") {
  73                         $hstring="host=$server ";
  74                 }
  75                 if ($port!=false && $port!="") {
  76                         $hstring .= "port=$port ";
  77                 }
  78
  79                 if (!strlen($user)) { ## e.g. the class is being loaded
  80                         return;
  81                 }
  82
  83                 error_reporting( E_ALL );
  84                 @$this->mConn = pg_connect("$hstring dbname=$dbName user=$user password=$password");
  85
  86                 if ( $this->mConn == false ) {
  87                         wfDebug( "DB connection error\n" );
  88                         wfDebug( "Server: $server, Database: $dbName, User: $user, Password: " . substr( $password, 0, 3 ) . "...\n" );
  89                         wfDebug( $this->lastError()."\n" );
  90                         return false;
  91                 }
  92
  93                 $this->mOpened = true;
  94                 ## If this is the initial connection, setup the schema stuff and possibly create the user
  95                 if (defined('MEDIAWIKI_INSTALL')) {
  96                         global $wgDBname, $wgDBuser, $wgDBpassword, $wgDBsuperuser, $wgDBmwschema,
  97                                 $wgDBts2schema;
  98
  99                         print "<li>Checking the version of Postgres...";
 100                         $version = $this->getServerVersion();
 101                         $PGMINVER = "8.1";
 102                         if ($this->numeric_version < $PGMINVER) {
 103                                 print "<b>FAILED</b>. Required version is $PGMINVER. You have $this->numeric_version ($version)</li>\n";
 104                                 dieout("</ul>");
 105                         }
 106                         print "version $this->numeric_version is OK.</li>\n";
 107
 108                         $safeuser = $this->quote_ident($wgDBuser);
 109                         ## Are we connecting as a superuser for the first time?
 110                         if ($wgDBsuperuser) {
 111                                 ## Are we really a superuser? Check out our rights
 112                                 $SQL = "SELECT
 113                                                 CASE WHEN usesuper IS TRUE THEN
 114                                                         CASE WHEN usecreatedb IS TRUE THEN 3 ELSE 1 END
 115                                                         ELSE CASE WHEN usecreatedb IS TRUE THEN 2 ELSE 0 END
 116                         END AS rights
 117                                                 FROM pg_catalog.pg_user WHERE usename = " . $this->addQuotes($wgDBsuperuser);
 118                                 $rows = $this->numRows($res = $this->doQuery($SQL));
 119                                 if (!$rows) {
 120                                         print "<li>ERROR: Could not read permissions for user \"$wgDBsuperuser\"</li>\n";
 121                                         dieout('</ul>');
 122                                 }
 123                                 $perms = pg_fetch_result($res, 0, 0);
 124
 125                                 $SQL = "SELECT 1 FROM pg_catalog.pg_user WHERE usename = " . $this->addQuotes($wgDBuser);
 126                                 $rows = $this->numRows($this->doQuery($SQL));
 127                                 if ($rows) {
 128                                         print "<li>User \"$wgDBuser\" already exists, skipping account creation.</li>";
 129                                 }
 130                                 else {
 131                                         if ($perms != 1 and $perms != 3) {
 132                                                 print "<li>ERROR: the user \"$wgDBsuperuser\" cannot create other users. ";
 133                                                 print 'Please use a different Postgres user.</li>';
 134                                                 dieout('</ul>');
 135                                         }
 136                                         print "<li>Creating user <b>$wgDBuser</b>...";
 137                                         $safepass = $this->addQuotes($wgDBpassword);
 138                                         $SQL = "CREATE USER $safeuser NOCREATEDB PASSWORD $safepass";
 139                                         $this->doQuery($SQL);
 140                                         print "OK</li>\n";
 141                                 }
 142                                 ## User now exists, check out the database
 143                                 if ($dbName != $wgDBname) {
 144                                         $SQL = "SELECT 1 FROM pg_catalog.pg_database WHERE datname = " . $this->addQuotes($wgDBname);
 145                                         $rows = $this->numRows($this->doQuery($SQL));
 146                                         if ($rows) {
 147                                                 print "<li>Database \"$wgDBname\" already exists, skipping database creation.</li>";
 148                                         }
 149                                         else {
 150                                                 if ($perms < 2) {
 151                                                         print "<li>ERROR: the user \"$wgDBsuperuser\" cannot create databases. ";
 152                                                         print 'Please use a different Postgres user.</li>';
 153                                                         dieout('</ul>');
 154                                                 }
 155                                                 print "<li>Creating database <b>$wgDBname</b>...";
 156                                                 $safename = $this->quote_ident($wgDBname);
 157                                                 $SQL = "CREATE DATABASE $safename OWNER $safeuser ";
 158                                                 $this->doQuery($SQL);
 159                                                 print "OK</li>\n";
 160                                                 ## Hopefully tsearch2 and plpgsql are in template1...
 161                                         }
 162
 163                                         ## Reconnect to check out tsearch2 rights for this user
 164                                         print "<li>Connecting to \"$wgDBname\" as superuser \"$wgDBsuperuser\" to check rights...";
 165                                         @$this->mConn = pg_connect("$hstring dbname=$wgDBname user=$user password=$password");
 166                                         if ( $this->mConn == false ) {
 167                                                 print "<b>FAILED TO CONNECT!</b></li>";
 168                                                 dieout("</ul>");
 169                                         }
 170                                         print "OK</li>\n";
 171                                 }
 172
 173                                 ## Tsearch2 checks
 174                                 print "<li>Checking that tsearch2 is installed in the database \"$wgDBname\"...";
 175                                 if (! $this->tableExists("pg_ts_cfg", $wgDBts2schema)) {
 176                                         print "<b>FAILED</b>. tsearch2 must be installed in the database \"$wgDBname\".";
 177                                         print "Please see <a href='http://www.devx.com/opensource/Article/21674/0/page/2'>this article</a>";
 178                                         print " for instructions or ask on #postgresql on irc.freenode.net</li>\n";
 179                                         dieout("</ul>");
 180                                 }
 181                                 print "OK</li>\n";
 182                                 print "<li>Ensuring that user \"$wgDBuser\" has select rights on the tsearch2 tables...";
 183                                 foreach (array('cfg','cfgmap','dict','parser') as $table) {
 184                                         $SQL = "GRANT SELECT ON pg_ts_$table TO $safeuser";
 185                                         $this->doQuery($SQL);
 186                                 }
 187                                 print "OK</li>\n";
 188
 189
 190                                 ## Setup the schema for this user if needed
 191                                 $result = $this->schemaExists($wgDBmwschema);
 192                                 $safeschema = $this->quote_ident($wgDBmwschema);
 193                                 if (!$result) {
 194                                         print "<li>Creating schema <b>$wgDBmwschema</b> ...";
 195                                         $result = $this->doQuery("CREATE SCHEMA $safeschema AUTHORIZATION $safeuser");
 196                                         if (!$result) {
 197                                                 print "<b>FAILED</b>.</li>\n";
 198                                                 dieout("</ul>");
 199                                         }
 200                                         print "OK</li>\n";
 201                                 }
 202                                 else {
 203                                         print "<li>Schema already exists, explicitly granting rights...\n";
 204                                         $safeschema2 = $this->addQuotes($wgDBmwschema);
 205                                         $SQL = "SELECT 'GRANT ALL ON '||pg_catalog.quote_ident(relname)||' TO $safeuser;'\n".
 206                                                         "FROM pg_catalog.pg_class p, pg_catalog.pg_namespace n\n".
 207                                                         "WHERE relnamespace = n.oid AND n.nspname = $safeschema2\n".
 208                                                         "AND p.relkind IN ('r','S','v')\n";
 209                                         $SQL .= "UNION\n";
 210                                         $SQL .= "SELECT 'GRANT ALL ON FUNCTION '||pg_catalog.quote_ident(proname)||'('||\n".
 211                                                         "pg_catalog.oidvectortypes(p.proargtypes)||') TO $safeuser;'\n".
 212                                                         "FROM pg_catalog.pg_proc p, pg_catalog.pg_namespace n\n".
 213                                                         "WHERE p.pronamespace = n.oid AND n.nspname = $safeschema2";
 214                                         $res = $this->doQuery($SQL);
 215                                         if (!$res) {
 216                                                 print "<b>FAILED</b>. Could not set rights for the user.</li>\n";
 217                                                 dieout("</ul>");
 218                                         }
 219                                         $this->doQuery("SET search_path = $safeschema");
 220                                         $rows = $this->numRows($res);
 221                                         while ($rows) {
 222                                                 $rows--;
 223                                                 $this->doQuery(pg_fetch_result($res, $rows, 0));
 224                                         }
 225                                         print "OK</li>";
 226                                 }
 227
 228                                 $wgDBsuperuser = '';
 229                                 return true; ## Reconnect as regular user
 230                         }
 231
 232                 if (!defined('POSTGRES_SEARCHPATH')) {
 233
 234                         ## Do we have the basic tsearch2 table?
 235                         print "<li>Checking for tsearch2 in the schema \"$wgDBts2schema\"...";
 236                         if (! $this->tableExists("pg_ts_dict", $wgDBts2schema)) {
 237                                 print "<b>FAILED</b>. Make sure tsearch2 is installed. See <a href=";
 238                                 print "'http://www.devx.com/opensource/Article/21674/0/page/2'>this article</a>";
 239                                 print " for instructions.</li>\n";
 240                                 dieout("</ul>");
 241                         }
 242                         print "OK</li>\n";
 243
 244                         ## Does this user have the rights to the tsearch2 tables?
 245                         $ctype = pg_fetch_result($this->doQuery("SHOW lc_ctype"),0,0);
 246                         print "<li>Checking tsearch2 permissions...";
 247                         ## Let's check all four, just to be safe
 248                         error_reporting( 0 );
 249                         $ts2tables = array('cfg','cfgmap','dict','parser');
 250                         foreach ( $ts2tables AS $tname ) {
 251                                 $SQL = "SELECT count(*) FROM $wgDBts2schema.pg_ts_$tname";
 252                                 $res = $this->doQuery($SQL);
 253                                 if (!$res) {
 254                                         print "<b>FAILED</b> to access pg_ts_$tname. Make sure that the user ".
 255                                         "\"$wgDBuser\" has SELECT access to all four tsearch2 tables</li>\n";
 256                                         dieout("</ul>");
 257                                 }
 258                         }
 259                         $SQL = "SELECT ts_name FROM $wgDBts2schema.pg_ts_cfg WHERE locale = '$ctype'";
 260                         $SQL .= " ORDER BY CASE WHEN ts_name <> 'default' THEN 1 ELSE 0 END";
 261                         $res = $this->doQuery($SQL);
 262                         error_reporting( E_ALL );
 263                         if (!$res) {
 264                                 print "<b>FAILED</b>. Could not determine the tsearch2 locale information</li>\n";
 265                                 dieout("</ul>");
 266                         }
 267                         print "OK</li>";
 268
 269                         ## Will the current locale work? Can we force it to?
 270                         print "<li>Verifying tsearch2 locale with $ctype...";
 271                         $rows = $this->numRows($res);
 272                         $resetlocale = 0;
 273                         if (!$rows) {
 274                                 print "<b>not found</b></li>\n";
 275                                 print "<li>Attempting to set default tsearch2 locale to \"$ctype\"...";
 276                                 $resetlocale = 1;
 277                         }
 278                         else {
 279                                 $tsname = pg_fetch_result($res, 0, 0);
 280                                 if ($tsname != 'default') {
 281                                         print "<b>not set to default ($tsname)</b>";
 282                                         print "<li>Attempting to change tsearch2 default locale to \"$ctype\"...";
 283                                         $resetlocale = 1;
 284                                 }
 285                         }
 286                         if ($resetlocale) {
 287                                 $SQL = "UPDATE $wgDBts2schema.pg_ts_cfg SET locale = '$ctype' WHERE ts_name = 'default'";
 288                                 $res = $this->doQuery($SQL);
 289                                 if (!$res) {
 290                                         print "<b>FAILED</b>. ";
 291                                         print "Please make sure that the locale in pg_ts_cfg for \"default\" is set to \"ctype\"</li>\n";
 292                                         dieout("</ul>");
 293                                 }
 294                                 print "OK</li>";
 295                         }
 296
 297                         ## Final test: try out a simple tsearch2 query
 298                         $SQL = "SELECT $wgDBts2schema.to_tsvector('default','MediaWiki tsearch2 testing')";
 299                         $res = $this->doQuery($SQL);
 300                         if (!$res) {
 301                                 print "<b>FAILED</b>. Specifically, \"$SQL\" did not work.</li>";
 302                                 dieout("</ul>");
 303                         }
 304                         print "OK</li>";
 305
 306                         ## Do we have plpgsql installed?
 307                         print "<li>Checking for Pl/Pgsql ...";
 308                         $SQL = "SELECT 1 FROM pg_catalog.pg_language WHERE lanname = 'plpgsql'";
 309                         $rows = $this->numRows($this->doQuery($SQL));
 310                         if ($rows < 1) {
 311                                 // plpgsql is not installed, but if we have a pg_pltemplate table, we should be able to create it
 312                                 print "not installed. Attempting to install Pl/Pgsql ...";
 313                                 $SQL = "SELECT 1 FROM pg_catalog.pg_class c JOIN pg_catalog.pg_namespace n ON (n.oid = c.relnamespace) ".
 314                                         "WHERE relname = 'pg_pltemplate' AND nspname='pg_catalog'";
 315                                 $rows = $this->numRows($this->doQuery($SQL));
 316                                 if ($rows >= 1) {
 317                                         $result = $this->doQuery("CREATE LANGUAGE plpgsql");
 318                                         if (!$result) {
 319                                                 print "<b>FAILED</b>. You need to install the language plpgsql in the database <tt>$wgDBname</tt></li>";
 320                                                 dieout("</ul>");
 321                                         }
 322                                 }
 323                                 else {
 324                                         print "<b>FAILED</b>. You need to install the language plpgsql in the database <tt>$wgDBname</tt></li>";
 325                                         dieout("</ul>");
 326                                 }
 327                         }
 328                         print "OK</li>\n";
 329
 330                         ## Does the schema already exist? Who owns it?
 331                         $result = $this->schemaExists($wgDBmwschema);
 332                         if (!$result) {
 333                                 print "<li>Creating schema <b>$wgDBmwschema</b> ...";
 334                                 error_reporting( 0 );
 335                                 $result = $this->doQuery("CREATE SCHEMA $wgDBmwschema");
 336                                 error_reporting( E_ALL );
 337                                 if (!$result) {
 338                                         print "<b>FAILED</b>. The user \"$wgDBuser\" must be able to access the schema. ".
 339                                         "You can try making them the owner of the database, or try creating the schema with a ".
 340                                         "different user, and then grant access to the \"$wgDBuser\" user.</li>\n";
 341                                         dieout("</ul>");
 342                                 }
 343                                 print "OK</li>\n";
 344                         }
 345                         else if ($result != $user) {
 346                                 print "<li>Schema \"$wgDBmwschema\" exists but is not owned by \"$user\". Not ideal.</li>\n";
 347                         }
 348                         else {
 349                                 print "<li>Schema \"$wgDBmwschema\" exists and is owned by \"$user\". Excellent.</li>\n";
 350                         }
 351
 352                         ## Fix up the search paths if needed
 353                         print "<li>Setting the search path for user \"$user\" ...";
 354                         $path = $this->quote_ident($wgDBmwschema);
 355                         if ($wgDBts2schema !== $wgDBmwschema)
 356                                 $path .= ", ". $this->quote_ident($wgDBts2schema);
 357                         if ($wgDBmwschema !== 'public' and $wgDBts2schema !== 'public')
 358                                 $path .= ", public";
 359                         $SQL = "ALTER USER $safeuser SET search_path = $path";
 360                         $result = pg_query($this->mConn, $SQL);
 361                         if (!$result) {
 362                                 print "<b>FAILED</b>.</li>\n";
 363                                 dieout("</ul>");
 364                         }
 365                         print "OK</li>\n";
 366                         ## Set for the rest of this session
 367                         $SQL = "SET search_path = $path";
 368                         $result = pg_query($this->mConn, $SQL);
 369                         if (!$result) {
 370                                 print "<li>Failed to set search_path</li>\n";
 371                                 dieout("</ul>");
 372                         }
 373                         define( "POSTGRES_SEARCHPATH", $path );
 374                 }}
 375
 376                 global $wgCommandLineMode;
 377                 ## If called from the command-line (e.g. importDump), only show errors
 378                 if ($wgCommandLineMode) {
 379                         $this->doQuery("SET client_min_messages = 'ERROR'");
 380                 }
 381
 382                 return $this->mConn;
 383         }
 384
 385         /**
 386          * Closes a database connection, if it is open
 387          * Returns success, true if already closed
 388          */
 389         function close() {
 390                 $this->mOpened = false;
 391                 if ( $this->mConn ) {
 392                         return pg_close( $this->mConn );
 393                 } else {
 394                         return true;
 395                 }
 396         }
 397
 398         function doQuery( $sql ) {
 399                 return $this->mLastResult=pg_query( $this->mConn , $sql);
 400         }
 401
 402         function queryIgnore( $sql, $fname = '' ) {
 403                 return $this->query( $sql, $fname, true );
 404         }
 405
 406         function freeResult( $res ) {
 407                 if ( !@pg_free_result( $res ) ) {
 408                         throw new DBUnexpectedError($this,  "Unable to free Postgres result\n" );
 409                 }
 410         }
 411
 412         function fetchObject( $res ) {
 413                 @$row = pg_fetch_object( $res );
 414                 # FIXME: HACK HACK HACK HACK debug
 415
 416                 # TODO:
 417                 # hashar : not sure if the following test really trigger if the object
 418                 #          fetching failled.
 419                 if( pg_last_error($this->mConn) ) {
 420                         throw new DBUnexpectedError($this,  'SQL error: ' . htmlspecialchars( pg_last_error($this->mConn) ) );
 421                 }
 422                 return $row;
 423         }
 424
 425         function fetchRow( $res ) {
 426                 @$row = pg_fetch_array( $res );
 427                 if( pg_last_error($this->mConn) ) {
 428                         throw new DBUnexpectedError($this,  'SQL error: ' . htmlspecialchars( pg_last_error($this->mConn) ) );
 429                 }
 430                 return $row;
 431         }
 432
 433         function numRows( $res ) {
 434                 @$n = pg_num_rows( $res );
 435                 if( pg_last_error($this->mConn) ) {
 436                         throw new DBUnexpectedError($this,  'SQL error: ' . htmlspecialchars( pg_last_error($this->mConn) ) );
 437                 }
 438                 return $n;
 439         }
 440         function numFields( $res ) { return pg_num_fields( $res ); }
 441         function fieldName( $res, $n ) { return pg_field_name( $res, $n ); }
 442
 443         /**
 444          * This must be called after nextSequenceVal
 445          */
 446         function insertId() {
 447                 return $this->mInsertId;
 448         }
 449
 450         function dataSeek( $res, $row ) { return pg_result_seek( $res, $row ); }
 451         function lastError() {
 452                 if ( $this->mConn ) {
 453                         return pg_last_error();
 454                 }
 455                 else {
 456                         return "No database connection";
 457                 }
 458         }
 459         function lastErrno() {
 460                 return pg_last_error() ? 1 : 0;
 461         }
 462
 463         function affectedRows() {
 464                 return pg_affected_rows( $this->mLastResult );
 465         }
 466
 467         /**
 468          * Returns information about an index
 469          * If errors are explicitly ignored, returns NULL on failure
 470          */
 471         function indexInfo( $table, $index, $fname = 'Database::indexExists' ) {
 472                 $sql = "SELECT indexname FROM pg_indexes WHERE tablename='$table'";
 473                 $res = $this->query( $sql, $fname );
 474                 if ( !$res ) {
 475                         return NULL;
 476                 }
 477
 478                 while ( $row = $this->fetchObject( $res ) ) {
 479                         if ( $row->indexname == $index ) {
 480                                 return $row;
 481
 482                                 // BUG: !!!! This code needs to be synced up with database.php
 483
 484                         }
 485                 }
 486                 return false;
 487         }
 488
 489         function indexUnique ($table, $index, $fname = 'Database::indexUnique' ) {
 490                 $sql = "SELECT indexname FROM pg_indexes WHERE tablename='{$table}'".
 491                         " AND indexdef LIKE 'CREATE UNIQUE%({$index})'";
 492                 $res = $this->query( $sql, $fname );
 493                 if ( !$res )
 494                         return NULL;
 495                 while ($row = $this->fetchObject( $res ))
 496                         return true;
 497                 return false;
 498
 499         }
 500
 501         function insert( $table, $a, $fname = 'Database::insert', $options = array() ) {
 502                 # Postgres doesn't support options
 503                 # We have a go at faking one of them
 504                 # TODO: DELAYED, LOW_PRIORITY
 505
 506                 if ( !is_array($options))
 507                         $options = array($options);
 508
 509                 if ( in_array( 'IGNORE', $options ) )
 510                         $oldIgnore = $this->ignoreErrors( true );
 511
 512                 # IGNORE is performed using single-row inserts, ignoring errors in each
 513                 # FIXME: need some way to distiguish between key collision and other types of error
 514                 $oldIgnore = $this->ignoreErrors( true );
 515                 if ( !is_array( reset( $a ) ) ) {
 516                         $a = array( $a );
 517                 }
 518                 foreach ( $a as $row ) {
 519                         parent::insert( $table, $row, $fname, array() );
 520                 }
 521                 $this->ignoreErrors( $oldIgnore );
 522                 $retVal = true;
 523
 524                 if ( in_array( 'IGNORE', $options ) )
 525                         $this->ignoreErrors( $oldIgnore );
 526
 527                 return $retVal;
 528         }
 529
 530         function tableName( $name ) {
 531                 # Replace reserved words with better ones
 532                 switch( $name ) {
 533                         case 'user':
 534                                 return 'mwuser';
 535                         case 'text':
 536                                 return 'pagecontent';
 537                         default:
 538                                 return $name;
 539                 }
 540         }
 541
 542         /**
 543          * Return the next in a sequence, save the value for retrieval via insertId()
 544          */
 545         function nextSequenceValue( $seqName ) {
 546                 $safeseq = preg_replace( "/'/", "''", $seqName );
 547                 $res = $this->query( "SELECT nextval('$safeseq')" );
 548                 $row = $this->fetchRow( $res );
 549                 $this->mInsertId = $row[0];
 550                 $this->freeResult( $res );
 551                 return $this->mInsertId;
 552         }
 553
 554         /**
 555          * Postgres does not have a "USE INDEX" clause, so return an empty string
 556          */
 557         function useIndexClause( $index ) {
 558                 return '';
 559         }
 560
 561         # REPLACE query wrapper
 562         # Postgres simulates this with a DELETE followed by INSERT
 563         # $row is the row to insert, an associative array
 564         # $uniqueIndexes is an array of indexes. Each element may be either a
 565         # field name or an array of field names
 566         #
 567         # It may be more efficient to leave off unique indexes which are unlikely to collide.
 568         # However if you do this, you run the risk of encountering errors which wouldn't have
 569         # occurred in MySQL
 570         function replace( $table, $uniqueIndexes, $rows, $fname = 'Database::replace' ) {
 571                 $table = $this->tableName( $table );
 572
 573                 if (count($rows)==0) {
 574                         return;
 575                 }
 576
 577                 # Single row case
 578                 if ( !is_array( reset( $rows ) ) ) {
 579                         $rows = array( $rows );
 580                 }
 581
 582                 foreach( $rows as $row ) {
 583                         # Delete rows which collide
 584                         if ( $uniqueIndexes ) {
 585                                 $sql = "DELETE FROM $table WHERE ";
 586                                 $first = true;
 587                                 foreach ( $uniqueIndexes as $index ) {
 588                                         if ( $first ) {
 589                                                 $first = false;
 590                                                 $sql .= "(";
 591                                         } else {
 592                                                 $sql .= ') OR (';
 593                                         }
 594                                         if ( is_array( $index ) ) {
 595                                                 $first2 = true;
 596                                                 foreach ( $index as $col ) {
 597                                                         if ( $first2 ) {
 598                                                                 $first2 = false;
 599                                                         } else {
 600                                                                 $sql .= ' AND ';
 601                                                         }
 602                                                         $sql .= $col.'=' . $this->addQuotes( $row[$col] );
 603                                                 }
 604                                         } else {
 605                                                 $sql .= $index.'=' . $this->addQuotes( $row[$index] );
 606                                         }
 607                                 }
 608                                 $sql .= ')';
 609                                 $this->query( $sql, $fname );
 610                         }
 611
 612                         # Now insert the row
 613                         $sql = "INSERT INTO $table (" . $this->makeList( array_keys( $row ), LIST_NAMES ) .') VALUES (' .
 614                                 $this->makeList( $row, LIST_COMMA ) . ')';
 615                         $this->query( $sql, $fname );
 616                 }
 617         }
 618
 619         # DELETE where the condition is a join
 620         function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds, $fname = "Database::deleteJoin" ) {
 621                 if ( !$conds ) {
 622                         throw new DBUnexpectedError($this,  'Database::deleteJoin() called with empty $conds' );
 623                 }
 624
 625                 $delTable = $this->tableName( $delTable );
 626                 $joinTable = $this->tableName( $joinTable );
 627                 $sql = "DELETE FROM $delTable WHERE $delVar IN (SELECT $joinVar FROM $joinTable ";
 628                 if ( $conds != '*' ) {
 629                         $sql .= 'WHERE ' . $this->makeList( $conds, LIST_AND );
 630                 }
 631                 $sql .= ')';
 632
 633                 $this->query( $sql, $fname );
 634         }
 635
 636         # Returns the size of a text field, or -1 for "unlimited"
 637         function textFieldSize( $table, $field ) {
 638                 $table = $this->tableName( $table );
 639                 $sql = "SELECT t.typname as ftype,a.atttypmod as size
 640                         FROM pg_class c, pg_attribute a, pg_type t
 641                         WHERE relname='$table' AND a.attrelid=c.oid AND
 642                                 a.atttypid=t.oid and a.attname='$field'";
 643                 $res =$this->query($sql);
 644                 $row=$this->fetchObject($res);
 645                 if ($row->ftype=="varchar") {
 646                         $size=$row->size-4;
 647                 } else {
 648                         $size=$row->size;
 649                 }
 650                 $this->freeResult( $res );
 651                 return $size;
 652         }
 653
 654         function lowPriorityOption() {
 655                 return '';
 656         }
 657
 658         function limitResult($sql, $limit,$offset) {
 659                 return "$sql LIMIT $limit ".(is_numeric($offset)?" OFFSET {$offset} ":"");
 660         }
 661
 662         /**
 663          * Returns an SQL expression for a simple conditional.
 664          * Uses CASE on Postgres
 665          *
 666          * @param string $cond SQL expression which will result in a boolean value
 667          * @param string $trueVal SQL expression to return if true
 668          * @param string $falseVal SQL expression to return if false
 669          * @return string SQL fragment
 670          */
 671         function conditional( $cond, $trueVal, $falseVal ) {
 672                 return " (CASE WHEN $cond THEN $trueVal ELSE $falseVal END) ";
 673         }
 674
 675         function wasDeadlock() {
 676                 return $this->lastErrno() == '40P01';
 677         }
 678
 679         function timestamp( $ts=0 ) {
 680                 return wfTimestamp(TS_POSTGRES,$ts);
 681         }
 682
 683         /**
 684          * Return aggregated value function call
 685          */
 686         function aggregateValue ($valuedata,$valuename='value') {
 687                 return $valuedata;
 688         }
 689
 690
 691         function reportQueryError( $error, $errno, $sql, $fname, $tempIgnore = false ) {
 692                 # Ignore errors during error handling to avoid infinite recursion
 693                 $ignore = $this->ignoreErrors( true );
 694                 ++$this->mErrorCount;
 695
 696                 if ($ignore || $tempIgnore) {
 697                         wfDebug("SQL ERROR (ignored): $error\n");
 698                         $this->ignoreErrors( $ignore );
 699                 }
 700                 else {
 701                         $message = "A database error has occurred\n" .
 702                                 "Query: $sql\n" .
 703                                 "Function: $fname\n" .
 704                                 "Error: $errno $error\n";
 705                         throw new DBUnexpectedError($this, $message);
 706                 }
 707         }
 708
 709         /**
 710          * @return string wikitext of a link to the server software's web site
 711          */
 712         function getSoftwareLink() {
 713                 return "[http://www.postgresql.org/ PostgreSQL]";
 714         }
 715
 716         /**
 717          * @return string Version information from the database
 718          */
 719         function getServerVersion() {
 720                 $version = pg_fetch_result($this->doQuery("SELECT version()"),0,0);
 721                 $thisver = array();
 722                 if (!preg_match('/PostgreSQL (\d+\.\d+)(\S+)/', $version, $thisver)) {
 723                         die("Could not determine the numeric version from $version!");
 724                 }
 725                 $this->numeric_version = $thisver[1];
 726                 return $version;
 727         }
 728
 729
 730         /**
 731          * Query whether a given table exists (in the given schema, or the default mw one if not given)
 732          */
 733         function tableExists( $table, $schema = false ) {
 734                 global $wgDBmwschema;
 735                 if (! $schema )
 736                         $schema = $wgDBmwschema;
 737                 $etable = preg_replace("/'/", "''", $table);
 738                 $eschema = preg_replace("/'/", "''", $schema);
 739                 $SQL = "SELECT 1 FROM pg_catalog.pg_class c, pg_catalog.pg_namespace n "
 740                         . "WHERE c.relnamespace = n.oid AND c.relname = '$etable' AND n.nspname = '$eschema' "
 741                         . "AND c.relkind IN ('r','v')";
 742                 $res = $this->query( $SQL );
 743                 $count = $res ? pg_num_rows($res) : 0;
 744                 if ($res)
 745                         $this->freeResult( $res );
 746                 return $count;
 747         }
 748
 749
 750         /**
 751          * Query whether a given schema exists. Returns the name of the owner
 752          */
 753         function schemaExists( $schema ) {
 754                 $eschema = preg_replace("/'/", "''", $schema);
 755                 $SQL = "SELECT rolname FROM pg_catalog.pg_namespace n, pg_catalog.pg_roles r "
 756                                 ."WHERE n.nspowner=r.oid AND n.nspname = '$eschema'";
 757                 $res = $this->query( $SQL );
 758                 $owner = $res ? pg_num_rows($res) ? pg_fetch_result($res, 0, 0) : false : false;
 759                 if ($res)
 760                         $this->freeResult($res);
 761                 return $owner;
 762         }
 763
 764         /**
 765          * Query whether a given column exists in the mediawiki schema
 766          */
 767         function fieldExists( $table, $field ) {
 768                 global $wgDBmwschema;
 769                 $etable = preg_replace("/'/", "''", $table);
 770                 $eschema = preg_replace("/'/", "''", $wgDBmwschema);
 771                 $ecol = preg_replace("/'/", "''", $field);
 772                 $SQL = "SELECT 1 FROM pg_catalog.pg_class c, pg_catalog.pg_namespace n, pg_catalog.pg_attribute a "
 773                         . "WHERE c.relnamespace = n.oid AND c.relname = '$etable' AND n.nspname = '$eschema' "
 774                         . "AND a.attrelid = c.oid AND a.attname = '$ecol'";
 775                 $res = $this->query( $SQL );
 776                 $count = $res ? pg_num_rows($res) : 0;
 777                 if ($res)
 778                         $this->freeResult( $res );
 779                 return $count;
 780         }
 781
 782         function fieldInfo( $table, $field ) {
 783                 $res = $this->query( "SELECT $field FROM $table LIMIT 1" );
 784                 $type = pg_field_type( $res, 0 );
 785                 return $type;
 786         }
 787
 788         function begin( $fname = 'DatabasePostgrs::begin' ) {
 789                 $this->query( 'BEGIN', $fname );
 790                 $this->mTrxLevel = 1;
 791         }
 792         function immediateCommit( $fname = 'DatabasePostgres::immediateCommit' ) {
 793                 return true;
 794         }
 795         function commit( $fname = 'DatabasePostgres::commit' ) {
 796                 $this->query( 'COMMIT', $fname );
 797                 $this->mTrxLevel = 0;
 798         }
 799
 800         /* Not even sure why this is used in the main codebase... */
 801         function limitResultForUpdate($sql, $num) {
 802                 return $sql;
 803         }
 804
 805         function setup_database() {
 806                 global $wgVersion, $wgDBmwschema, $wgDBts2schema, $wgDBport, $wgDBuser;
 807
 808                 ## Make sure that we can write to the correct schema
 809                 ## If not, Postgres will happily and silently go to the next search_path item
 810                 $SQL = "CREATE TABLE $wgDBmwschema.mw_test_table(a int)";
 811                 error_reporting( 0 );
 812                 $res = $this->doQuery($SQL);
 813                 error_reporting( E_ALL );
 814                 if (!$res) {
 815                         print "<b>FAILED</b>. Make sure that the user \"$wgDBuser\" can write to the schema \"wgDBmwschema\"</li>\n";
 816                         dieout("</ul>");
 817                 }
 818
 819                 dbsource( "../maintenance/postgres/tables.sql", $this);
 820
 821                 ## Version-specific stuff
 822                 if ($this->numeric_version == 8.1) {
 823                         $this->doQuery("CREATE INDEX ts2_page_text ON pagecontent USING gist(textvector)");
 824                         $this->doQuery("CREATE INDEX ts2_page_title ON page USING gist(titlevector)");
 825                 }
 826                 else {
 827                         $this->doQuery("CREATE INDEX ts2_page_text ON pagecontent USING gin(textvector)");
 828                         $this->doQuery("CREATE INDEX ts2_page_title ON page USING gin(titlevector)");
 829                 }
 830
 831                 ## Update version information
 832                 $mwv = $this->addQuotes($wgVersion);
 833                 $pgv = $this->addQuotes($this->getServerVersion());
 834                 $pgu = $this->addQuotes($this->mUser);
 835                 $mws = $this->addQuotes($wgDBmwschema);
 836                 $tss = $this->addQuotes($wgDBts2schema);
 837                 $pgp = $this->addQuotes($wgDBport);
 838                 $dbn = $this->addQuotes($this->mDBname);
 839                 $ctype = pg_fetch_result($this->doQuery("SHOW lc_ctype"),0,0);
 840
 841                 $SQL = "UPDATE mediawiki_version SET mw_version=$mwv, pg_version=$pgv, pg_user=$pgu, ".
 842                                 "mw_schema = $mws, ts2_schema = $tss, pg_port=$pgp, pg_dbname=$dbn, ".
 843                                 "ctype = '$ctype' ".
 844                                 "WHERE type = 'Creation'";
 845                 $this->query($SQL);
 846
 847                 ## Avoid the non-standard "REPLACE INTO" syntax
 848                 $f = fopen( "../maintenance/interwiki.sql", 'r' );
 849                 if ($f == false ) {
 850                         dieout( "<li>Could not find the interwiki.sql file");
 851                 }
 852                 ## We simply assume it is already empty as we have just created it
 853                 $SQL = "INSERT INTO interwiki(iw_prefix,iw_url,iw_local) VALUES ";
 854                 while ( ! feof( $f ) ) {
 855                         $line = fgets($f,1024);
 856                         $matches = array();
 857                         if (!preg_match('/^\s*(\(.+?),(\d)\)/', $line, $matches)) {
 858                                 continue;
 859                         }
 860                         $this->query("$SQL $matches[1],$matches[2])");
 861                 }
 862                 print " (table interwiki successfully populated)...\n";
 863         }
 864
 865         function encodeBlob($b) {
 866                 return array('bytea',pg_escape_bytea($b));
 867         }
 868         function decodeBlob($b) {
 869                 return pg_unescape_bytea( $b );
 870         }
 871
 872         function strencode( $s ) { ## Should not be called by us
 873                 return pg_escape_string( $s );
 874         }
 875
 876         function addQuotes( $s ) {
 877                 if ( is_null( $s ) ) {
 878                         return 'NULL';
 879                 } else if (is_array( $s )) { ## Assume it is bytea data
 880                         return "E'$s[1]'";
 881                 }
 882                 return "'" . pg_escape_string($s) . "'";
 883                 // Unreachable: return "E'" . pg_escape_string($s) . "'";
 884         }
 885
 886         function quote_ident( $s ) {
 887                 return '"' . preg_replace( '/"/', '""', $s) . '"';
 888         }
 889
 890         /* For now, does nothing */
 891         function selectDB( $db ) {
 892                 return true;
 893         }
 894
 895         /**
 896          * Returns an optional USE INDEX clause to go after the table, and a
 897          * string to go at the end of the query
 898          *
 899          * @private
 900          *
 901          * @param array $options an associative array of options to be turned into
 902          *              an SQL query, valid keys are listed in the function.
 903          * @return array
 904          */
 905         function makeSelectOptions( $options ) {
 906                 $tailOpts = '';
 907                 $startOpts = '';
 908
 909                 $noKeyOptions = array();
 910                 foreach ( $options as $key => $option ) {
 911                         if ( is_numeric( $key ) ) {
 912                                 $noKeyOptions[$option] = true;
 913                         }
 914                 }
 915
 916                 if ( isset( $options['GROUP BY'] ) ) $tailOpts .= " GROUP BY {$options['GROUP BY']}";
 917                 if ( isset( $options['ORDER BY'] ) ) $tailOpts .= " ORDER BY {$options['ORDER BY']}";
 918
 919                 if (isset($options['LIMIT'])) {
 920                         $tailOpts .= $this->limitResult('', $options['LIMIT'],
 921                                 isset($options['OFFSET']) ? $options['OFFSET'] : false);
 922                 }
 923
 924                 if ( isset( $noKeyOptions['FOR UPDATE'] ) ) $tailOpts .= ' FOR UPDATE';
 925                 if ( isset( $noKeyOptions['LOCK IN SHARE MODE'] ) ) $tailOpts .= ' LOCK IN SHARE MODE';
 926                 if ( isset( $noKeyOptions['DISTINCT'] ) && isset( $noKeyOptions['DISTINCTROW'] ) ) $startOpts .= 'DISTINCT';
 927
 928                 if ( isset( $options['USE INDEX'] ) && ! is_array( $options['USE INDEX'] ) ) {
 929                         $useIndex = $this->useIndexClause( $options['USE INDEX'] );
 930                 } else {
 931                         $useIndex = '';
 932                 }
 933
 934                 return array( $startOpts, $useIndex, $tailOpts );
 935         }
 936
 937         function ping() {
 938                 wfDebug( "Function ping() not written for DatabasePostgres.php yet");
 939                 return true;
 940         }
 941
 942
 943 } // end DatabasePostgres class
 944
 945 ?>