first commit

5 files changed, 1937 insertions, 0 deletions

diff --git a/www/wiki/includes/db/CloneDatabase.php b/www/wiki/includes/db/CloneDatabase.php
new file mode 100644
index 00000000..edb54aee
--- /dev/null
+++ b/www/wiki/includes/db/CloneDatabase.php
@@ -0,0 +1,140 @@
+<?php
+/**
+ * Helper class for making a copy of the database, mostly for unit testing.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ * http://www.gnu.org/copyleft/gpl.html
+ *
+ * @file
+ * @ingroup Database
+ */
+use MediaWiki\MediaWikiServices;
+use Wikimedia\Rdbms\IMaintainableDatabase;
+
+class CloneDatabase {
+	/** @var string Table prefix for cloning */
+	private $newTablePrefix = '';
+
+	/** @var string Current table prefix */
+	private $oldTablePrefix = '';
+
+	/** @var array List of tables to be cloned */
+	private $tablesToClone = [];
+
+	/** @var bool Should we DROP tables containing the new names? */
+	private $dropCurrentTables = true;
+
+	/** @var bool Whether to use temporary tables or not */
+	private $useTemporaryTables = true;
+
+	/** @var IMaintainableDatabase */
+	private $db;
+
+	/**
+	 * @param IMaintainableDatabase $db A database subclass
+	 * @param array $tablesToClone An array of tables to clone, unprefixed
+	 * @param string $newTablePrefix Prefix to assign to the tables
+	 * @param string $oldTablePrefix Prefix on current tables, if not $wgDBprefix
+	 * @param bool $dropCurrentTables
+	 */
+	public function __construct( IMaintainableDatabase $db, array $tablesToClone,
+		$newTablePrefix, $oldTablePrefix = null, $dropCurrentTables = true
+	) {
+		$this->db = $db;
+		$this->tablesToClone = $tablesToClone;
+		$this->newTablePrefix = $newTablePrefix;
+		$this->oldTablePrefix = $oldTablePrefix !== null ? $oldTablePrefix : $this->db->tablePrefix();
+		$this->dropCurrentTables = $dropCurrentTables;
+	}
+
+	/**
+	 * Set whether to use temporary tables or not
+	 * @param bool $u Use temporary tables when cloning the structure
+	 */
+	public function useTemporaryTables( $u = true ) {
+		$this->useTemporaryTables = $u;
+	}
+
+	/**
+	 * Clone the table structure
+	 */
+	public function cloneTableStructure() {
+		global $wgSharedTables, $wgSharedDB;
+		foreach ( $this->tablesToClone as $tbl ) {
+			if ( $wgSharedDB && in_array( $tbl, $wgSharedTables, true ) ) {
+				// Shared tables don't work properly when cloning due to
+				// how prefixes are handled (T67654)
+				throw new RuntimeException( "Cannot clone shared table $tbl." );
+			}
+			# Clean up from previous aborted run.  So that table escaping
+			# works correctly across DB engines, we need to change the pre-
+			# fix back and forth so tableName() works right.
+
+			self::changePrefix( $this->oldTablePrefix );
+			$oldTableName = $this->db->tableName( $tbl, 'raw' );
+
+			self::changePrefix( $this->newTablePrefix );
+			$newTableName = $this->db->tableName( $tbl, 'raw' );
+
+			// Postgres: Temp tables are automatically deleted upon end of session
+			//           Same Temp table name hides existing table for current session
+			if ( $this->dropCurrentTables
+				&& !in_array( $this->db->getType(), [ 'oracle' ] )
+			) {
+				if ( $oldTableName === $newTableName ) {
+					// Last ditch check to avoid data loss
+					throw new LogicException( "Not dropping new table, as '$newTableName'"
+						. " is name of both the old and the new table." );
+				}
+				$this->db->dropTable( $tbl, __METHOD__ );
+				wfDebug( __METHOD__ . " dropping {$newTableName}\n" );
+				// Dropping the oldTable because the prefix was changed
+			}
+
+			# Create new table
+			wfDebug( __METHOD__ . " duplicating $oldTableName to $newTableName\n" );
+			$this->db->duplicateTableStructure(
+				$oldTableName, $newTableName, $this->useTemporaryTables );
+		}
+	}
+
+	/**
+	 * Change the prefix back to the original.
+	 * @param bool $dropTables Optionally drop the tables we created
+	 */
+	public function destroy( $dropTables = false ) {
+		if ( $dropTables ) {
+			self::changePrefix( $this->newTablePrefix );
+			foreach ( $this->tablesToClone as $tbl ) {
+				$this->db->dropTable( $tbl );
+			}
+		}
+		self::changePrefix( $this->oldTablePrefix );
+	}
+
+	/**
+	 * Change the table prefix on all open DB connections/
+	 *
+	 * @param string $prefix
+	 * @return void
+	 */
+	public static function changePrefix( $prefix ) {
+		global $wgDBprefix;
+
+		$lbFactory = MediaWikiServices::getInstance()->getDBLoadBalancerFactory();
+		$lbFactory->setDomainPrefix( $prefix );
+		$wgDBprefix = $prefix;
+	}
+}
diff --git a/www/wiki/includes/db/DatabaseOracle.php b/www/wiki/includes/db/DatabaseOracle.php
new file mode 100644
index 00000000..3362f0f9
--- /dev/null
+++ b/www/wiki/includes/db/DatabaseOracle.php
@@ -0,0 +1,1382 @@
+<?php
+/**
+ * This is the Oracle database abstraction layer.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ * http://www.gnu.org/copyleft/gpl.html
+ *
+ * @file
+ * @ingroup Database
+ */
+
+use Wikimedia\Rdbms\Database;
+use Wikimedia\Rdbms\Blob;
+use Wikimedia\Rdbms\ResultWrapper;
+use Wikimedia\Rdbms\DBConnectionError;
+use Wikimedia\Rdbms\DBUnexpectedError;
+
+/**
+ * @ingroup Database
+ */
+class DatabaseOracle extends Database {
+	/** @var resource */
+	protected $mLastResult = null;
+
+	/** @var int The number of rows affected as an integer */
+	protected $mAffectedRows;
+
+	/** @var bool */
+	private $ignoreDupValOnIndex = false;
+
+	/** @var bool|array */
+	private $sequenceData = null;
+
+	/** @var string Character set for Oracle database */
+	private $defaultCharset = 'AL32UTF8';
+
+	/** @var array */
+	private $mFieldInfoCache = [];
+
+	function __construct( array $p ) {
+		global $wgDBprefix;
+
+		if ( $p['tablePrefix'] == 'get from global' ) {
+			$p['tablePrefix'] = $wgDBprefix;
+		}
+		$p['tablePrefix'] = strtoupper( $p['tablePrefix'] );
+		parent::__construct( $p );
+		Hooks::run( 'DatabaseOraclePostInit', [ $this ] );
+	}
+
+	function __destruct() {
+		if ( $this->opened ) {
+			Wikimedia\suppressWarnings();
+			$this->close();
+			Wikimedia\restoreWarnings();
+		}
+	}
+
+	function getType() {
+		return 'oracle';
+	}
+
+	function implicitGroupby() {
+		return false;
+	}
+
+	function implicitOrderby() {
+		return false;
+	}
+
+	/**
+	 * Usually aborts on failure
+	 * @param string $server
+	 * @param string $user
+	 * @param string $password
+	 * @param string $dbName
+	 * @throws DBConnectionError
+	 * @return resource|null
+	 */
+	function open( $server, $user, $password, $dbName ) {
+		global $wgDBOracleDRCP;
+		if ( !function_exists( 'oci_connect' ) ) {
+			throw new DBConnectionError(
+				$this,
+				"Oracle functions missing, have you compiled PHP with the --with-oci8 option?\n " .
+					"(Note: if you recently installed PHP, you may need to restart your webserver\n " .
+					"and database)\n" );
+		}
+
+		$this->close();
+		$this->user = $user;
+		$this->password = $password;
+		// changed internal variables functions
+		// mServer now holds the TNS endpoint
+		// mDBname is schema name if different from username
+		if ( !$server ) {
+			// backward compatibillity (server used to be null and TNS was supplied in dbname)
+			$this->server = $dbName;
+			$this->dbName = $user;
+		} else {
+			$this->server = $server;
+			if ( !$dbName ) {
+				$this->dbName = $user;
+			} else {
+				$this->dbName = $dbName;
+			}
+		}
+
+		if ( !strlen( $user ) ) { # e.g. the class is being loaded
+			return null;
+		}
+
+		if ( $wgDBOracleDRCP ) {
+			$this->setFlag( DBO_PERSISTENT );
+		}
+
+		$session_mode = $this->flags & DBO_SYSDBA ? OCI_SYSDBA : OCI_DEFAULT;
+
+		Wikimedia\suppressWarnings();
+		if ( $this->flags & DBO_PERSISTENT ) {
+			$this->conn = oci_pconnect(
+				$this->user,
+				$this->password,
+				$this->server,
+				$this->defaultCharset,
+				$session_mode
+			);
+		} elseif ( $this->flags & DBO_DEFAULT ) {
+			$this->conn = oci_new_connect(
+				$this->user,
+				$this->password,
+				$this->server,
+				$this->defaultCharset,
+				$session_mode
+			);
+		} else {
+			$this->conn = oci_connect(
+				$this->user,
+				$this->password,
+				$this->server,
+				$this->defaultCharset,
+				$session_mode
+			);
+		}
+		Wikimedia\restoreWarnings();
+
+		if ( $this->user != $this->dbName ) {
+			// change current schema in session
+			$this->selectDB( $this->dbName );
+		}
+
+		if ( !$this->conn ) {
+			throw new DBConnectionError( $this, $this->lastError() );
+		}
+
+		$this->opened = true;
+
+		# removed putenv calls because they interfere with the system globaly
+		$this->doQuery( 'ALTER SESSION SET NLS_TIMESTAMP_FORMAT=\'DD-MM-YYYY HH24:MI:SS.FF6\'' );
+		$this->doQuery( 'ALTER SESSION SET NLS_TIMESTAMP_TZ_FORMAT=\'DD-MM-YYYY HH24:MI:SS.FF6\'' );
+		$this->doQuery( 'ALTER SESSION SET NLS_NUMERIC_CHARACTERS=\'.,\'' );
+
+		return $this->conn;
+	}
+
+	/**
+	 * Closes a database connection, if it is open
+	 * Returns success, true if already closed
+	 * @return bool
+	 */
+	protected function closeConnection() {
+		return oci_close( $this->conn );
+	}
+
+	function execFlags() {
+		return $this->trxLevel ? OCI_NO_AUTO_COMMIT : OCI_COMMIT_ON_SUCCESS;
+	}
+
+	protected function doQuery( $sql ) {
+		wfDebug( "SQL: [$sql]\n" );
+		if ( !StringUtils::isUtf8( $sql ) ) {
+			throw new InvalidArgumentException( "SQL encoding is invalid\n$sql" );
+		}
+
+		// handle some oracle specifics
+		// remove AS column/table/subquery namings
+		if ( !$this->getFlag( DBO_DDLMODE ) ) {
+			$sql = preg_replace( '/ as /i', ' ', $sql );
+		}
+
+		// Oracle has issues with UNION clause if the statement includes LOB fields
+		// So we do a UNION ALL and then filter the results array with array_unique
+		$union_unique = ( preg_match( '/\/\* UNION_UNIQUE \*\/ /', $sql ) != 0 );
+		// EXPLAIN syntax in Oracle is EXPLAIN PLAN FOR and it return nothing
+		// you have to select data from plan table after explain
+		$explain_id = MWTimestamp::getLocalInstance()->format( 'dmYHis' );
+
+		$sql = preg_replace(
+			'/^EXPLAIN /',
+			'EXPLAIN PLAN SET STATEMENT_ID = \'' . $explain_id . '\' FOR',
+			$sql,
+			1,
+			$explain_count
+		);
+
+		Wikimedia\suppressWarnings();
+
+		$this->mLastResult = $stmt = oci_parse( $this->conn, $sql );
+		if ( $stmt === false ) {
+			$e = oci_error( $this->conn );
+			$this->reportQueryError( $e['message'], $e['code'], $sql, __METHOD__ );
+
+			return false;
+		}
+
+		if ( !oci_execute( $stmt, $this->execFlags() ) ) {
+			$e = oci_error( $stmt );
+			if ( !$this->ignoreDupValOnIndex || $e['code'] != '1' ) {
+				$this->reportQueryError( $e['message'], $e['code'], $sql, __METHOD__ );
+
+				return false;
+			}
+		}
+
+		Wikimedia\restoreWarnings();
+
+		if ( $explain_count > 0 ) {
+			return $this->doQuery( 'SELECT id, cardinality "ROWS" FROM plan_table ' .
+				'WHERE statement_id = \'' . $explain_id . '\'' );
+		} elseif ( oci_statement_type( $stmt ) == 'SELECT' ) {
+			return new ORAResult( $this, $stmt, $union_unique );
+		} else {
+			$this->mAffectedRows = oci_num_rows( $stmt );
+
+			return true;
+		}
+	}
+
+	function queryIgnore( $sql, $fname = '' ) {
+		return $this->query( $sql, $fname, true );
+	}
+
+	/**
+	 * Frees resources associated with the LOB descriptor
+	 * @param ResultWrapper|ORAResult $res
+	 */
+	function freeResult( $res ) {
+		if ( $res instanceof ResultWrapper ) {
+			$res = $res->result;
+		}
+
+		$res->free();
+	}
+
+	/**
+	 * @param ResultWrapper|ORAResult $res
+	 * @return mixed
+	 */
+	function fetchObject( $res ) {
+		if ( $res instanceof ResultWrapper ) {
+			$res = $res->result;
+		}
+
+		return $res->fetchObject();
+	}
+
+	/**
+	 * @param ResultWrapper|ORAResult $res
+	 * @return mixed
+	 */
+	function fetchRow( $res ) {
+		if ( $res instanceof ResultWrapper ) {
+			$res = $res->result;
+		}
+
+		return $res->fetchRow();
+	}
+
+	/**
+	 * @param ResultWrapper|ORAResult $res
+	 * @return int
+	 */
+	function numRows( $res ) {
+		if ( $res instanceof ResultWrapper ) {
+			$res = $res->result;
+		}
+
+		return $res->numRows();
+	}
+
+	/**
+	 * @param ResultWrapper|ORAResult $res
+	 * @return int
+	 */
+	function numFields( $res ) {
+		if ( $res instanceof ResultWrapper ) {
+			$res = $res->result;
+		}
+
+		return $res->numFields();
+	}
+
+	function fieldName( $stmt, $n ) {
+		return oci_field_name( $stmt, $n );
+	}
+
+	function insertId() {
+		$res = $this->query( "SELECT lastval_pkg.getLastval FROM dual" );
+		$row = $this->fetchRow( $res );
+		return is_null( $row[0] ) ? null : (int)$row[0];
+	}
+
+	/**
+	 * @param mixed $res
+	 * @param int $row
+	 */
+	function dataSeek( $res, $row ) {
+		if ( $res instanceof ORAResult ) {
+			$res->seek( $row );
+		} else {
+			$res->result->seek( $row );
+		}
+	}
+
+	function lastError() {
+		if ( $this->conn === false ) {
+			$e = oci_error();
+		} else {
+			$e = oci_error( $this->conn );
+		}
+
+		return $e['message'];
+	}
+
+	function lastErrno() {
+		if ( $this->conn === false ) {
+			$e = oci_error();
+		} else {
+			$e = oci_error( $this->conn );
+		}
+
+		return $e['code'];
+	}
+
+	protected function fetchAffectedRowCount() {
+		return $this->mAffectedRows;
+	}
+
+	/**
+	 * Returns information about an index
+	 * If errors are explicitly ignored, returns NULL on failure
+	 * @param string $table
+	 * @param string $index
+	 * @param string $fname
+	 * @return bool
+	 */
+	function indexInfo( $table, $index, $fname = __METHOD__ ) {
+		return false;
+	}
+
+	function indexUnique( $table, $index, $fname = __METHOD__ ) {
+		return false;
+	}
+
+	function insert( $table, $a, $fname = __METHOD__, $options = [] ) {
+		if ( !count( $a ) ) {
+			return true;
+		}
+
+		if ( !is_array( $options ) ) {
+			$options = [ $options ];
+		}
+
+		if ( in_array( 'IGNORE', $options ) ) {
+			$this->ignoreDupValOnIndex = true;
+		}
+
+		if ( !is_array( reset( $a ) ) ) {
+			$a = [ $a ];
+		}
+
+		foreach ( $a as &$row ) {
+			$this->insertOneRow( $table, $row, $fname );
+		}
+		$retVal = true;
+
+		if ( in_array( 'IGNORE', $options ) ) {
+			$this->ignoreDupValOnIndex = false;
+		}
+
+		return $retVal;
+	}
+
+	private function fieldBindStatement( $table, $col, &$val, $includeCol = false ) {
+		$col_info = $this->fieldInfoMulti( $table, $col );
+		$col_type = $col_info != false ? $col_info->type() : 'CONSTANT';
+
+		$bind = '';
+		if ( is_numeric( $col ) ) {
+			$bind = $val;
+			$val = null;
+
+			return $bind;
+		} elseif ( $includeCol ) {
+			$bind = "$col = ";
+		}
+
+		if ( $val == '' && $val !== 0 && $col_type != 'BLOB' && $col_type != 'CLOB' ) {
+			$val = null;
+		}
+
+		if ( $val === 'NULL' ) {
+			$val = null;
+		}
+
+		if ( $val === null ) {
+			if ( $col_info != false && $col_info->isNullable() == 0 && $col_info->defaultValue() != null ) {
+				$bind .= 'DEFAULT';
+			} else {
+				$bind .= 'NULL';
+			}
+		} else {
+			$bind .= ':' . $col;
+		}
+
+		return $bind;
+	}
+
+	/**
+	 * @param string $table
+	 * @param array $row
+	 * @param string $fname
+	 * @return bool
+	 * @throws DBUnexpectedError
+	 */
+	private function insertOneRow( $table, $row, $fname ) {
+		global $wgContLang;
+
+		$table = $this->tableName( $table );
+		// "INSERT INTO tables (a, b, c)"
+		$sql = "INSERT INTO " . $table . " (" . implode( ',', array_keys( $row ) ) . ')';
+		$sql .= " VALUES (";
+
+		// for each value, append ":key"
+		$first = true;
+		foreach ( $row as $col => &$val ) {
+			if ( !$first ) {
+				$sql .= ', ';
+			} else {
+				$first = false;
+			}
+			if ( $this->isQuotedIdentifier( $val ) ) {
+				$sql .= $this->removeIdentifierQuotes( $val );
+				unset( $row[$col] );
+			} else {
+				$sql .= $this->fieldBindStatement( $table, $col, $val );
+			}
+		}
+		$sql .= ')';
+
+		$this->mLastResult = $stmt = oci_parse( $this->conn, $sql );
+		if ( $stmt === false ) {
+			$e = oci_error( $this->conn );
+			$this->reportQueryError( $e['message'], $e['code'], $sql, __METHOD__ );
+
+			return false;
+		}
+		foreach ( $row as $col => &$val ) {
+			$col_info = $this->fieldInfoMulti( $table, $col );
+			$col_type = $col_info != false ? $col_info->type() : 'CONSTANT';
+
+			if ( $val === null ) {
+				// do nothing ... null was inserted in statement creation
+			} elseif ( $col_type != 'BLOB' && $col_type != 'CLOB' ) {
+				if ( is_object( $val ) ) {
+					$val = $val->fetch();
+				}
+
+				// backward compatibility
+				if ( preg_match( '/^timestamp.*/i', $col_type ) == 1 && strtolower( $val ) == 'infinity' ) {
+					$val = $this->getInfinity();
+				}
+
+				$val = ( $wgContLang != null ) ? $wgContLang->checkTitleEncoding( $val ) : $val;
+				if ( oci_bind_by_name( $stmt, ":$col", $val, -1, SQLT_CHR ) === false ) {
+					$e = oci_error( $stmt );
+					$this->reportQueryError( $e['message'], $e['code'], $sql, __METHOD__ );
+
+					return false;
+				}
+			} else {
+				/** @var OCI_Lob[] $lob */
+				$lob[$col] = oci_new_descriptor( $this->conn, OCI_D_LOB );
+				if ( $lob[$col] === false ) {
+					$e = oci_error( $stmt );
+					throw new DBUnexpectedError( $this, "Cannot create LOB descriptor: " . $e['message'] );
+				}
+
+				if ( is_object( $val ) ) {
+					$val = $val->fetch();
+				}
+
+				if ( $col_type == 'BLOB' ) {
+					$lob[$col]->writeTemporary( $val, OCI_TEMP_BLOB );
+					oci_bind_by_name( $stmt, ":$col", $lob[$col], -1, OCI_B_BLOB );
+				} else {
+					$lob[$col]->writeTemporary( $val, OCI_TEMP_CLOB );
+					oci_bind_by_name( $stmt, ":$col", $lob[$col], -1, OCI_B_CLOB );
+				}
+			}
+		}
+
+		Wikimedia\suppressWarnings();
+
+		if ( oci_execute( $stmt, $this->execFlags() ) === false ) {
+			$e = oci_error( $stmt );
+			if ( !$this->ignoreDupValOnIndex || $e['code'] != '1' ) {
+				$this->reportQueryError( $e['message'], $e['code'], $sql, __METHOD__ );
+
+				return false;
+			} else {
+				$this->mAffectedRows = oci_num_rows( $stmt );
+			}
+		} else {
+			$this->mAffectedRows = oci_num_rows( $stmt );
+		}
+
+		Wikimedia\restoreWarnings();
+
+		if ( isset( $lob ) ) {
+			foreach ( $lob as $lob_v ) {
+				$lob_v->free();
+			}
+		}
+
+		if ( !$this->trxLevel ) {
+			oci_commit( $this->conn );
+		}
+
+		return oci_free_statement( $stmt );
+	}
+
+	function nativeInsertSelect( $destTable, $srcTable, $varMap, $conds, $fname = __METHOD__,
+		$insertOptions = [], $selectOptions = [], $selectJoinConds = []
+	) {
+		$destTable = $this->tableName( $destTable );
+
+		$sequenceData = $this->getSequenceData( $destTable );
+		if ( $sequenceData !== false &&
+			!isset( $varMap[$sequenceData['column']] )
+		) {
+			$varMap[$sequenceData['column']] = 'GET_SEQUENCE_VALUE(\'' . $sequenceData['sequence'] . '\')';
+		}
+
+		// count-alias subselect fields to avoid abigious definition errors
+		$i = 0;
+		foreach ( $varMap as &$val ) {
+			$val = $val . ' field' . ( $i++ );
+		}
+
+		$selectSql = $this->selectSQLText(
+			$srcTable,
+			array_values( $varMap ),
+			$conds,
+			$fname,
+			$selectOptions,
+			$selectJoinConds
+		);
+
+		$sql = "INSERT INTO $destTable (" . implode( ',', array_keys( $varMap ) ) . ') ' . $selectSql;
+
+		if ( in_array( 'IGNORE', $insertOptions ) ) {
+			$this->ignoreDupValOnIndex = true;
+		}
+
+		$retval = $this->query( $sql, $fname );
+
+		if ( in_array( 'IGNORE', $insertOptions ) ) {
+			$this->ignoreDupValOnIndex = false;
+		}
+
+		return $retval;
+	}
+
+	public function upsert( $table, array $rows, array $uniqueIndexes, array $set,
+		$fname = __METHOD__
+	) {
+		if ( !count( $rows ) ) {
+			return true; // nothing to do
+		}
+
+		if ( !is_array( reset( $rows ) ) ) {
+			$rows = [ $rows ];
+		}
+
+		$sequenceData = $this->getSequenceData( $table );
+		if ( $sequenceData !== false ) {
+			// add sequence column to each list of columns, when not set
+			foreach ( $rows as &$row ) {
+				if ( !isset( $row[$sequenceData['column']] ) ) {
+					$row[$sequenceData['column']] =
+						$this->addIdentifierQuotes( 'GET_SEQUENCE_VALUE(\'' .
+							$sequenceData['sequence'] . '\')' );
+				}
+			}
+		}
+
+		return parent::upsert( $table, $rows, $uniqueIndexes, $set, $fname );
+	}
+
+	function tableName( $name, $format = 'quoted' ) {
+		/*
+		Replace reserved words with better ones
+		Using uppercase because that's the only way Oracle can handle
+		quoted tablenames
+		*/
+		switch ( $name ) {
+			case 'user':
+				$name = 'MWUSER';
+				break;
+			case 'text':
+				$name = 'PAGECONTENT';
+				break;
+		}
+
+		return strtoupper( parent::tableName( $name, $format ) );
+	}
+
+	function tableNameInternal( $name ) {
+		$name = $this->tableName( $name );
+
+		return preg_replace( '/.*\.(.*)/', '$1', $name );
+	}
+
+	/**
+	 * Return sequence_name if table has a sequence
+	 *
+	 * @param string $table
+	 * @return bool
+	 */
+	private function getSequenceData( $table ) {
+		if ( $this->sequenceData == null ) {
+			$result = $this->doQuery( "SELECT lower(asq.sequence_name),
+				lower(atc.table_name),
+				lower(atc.column_name)
+			FROM all_sequences asq, all_tab_columns atc
+			WHERE decode(
+					atc.table_name,
+					'{$this->tablePrefix}MWUSER',
+					'{$this->tablePrefix}USER',
+					atc.table_name
+				) || '_' ||
+				atc.column_name || '_SEQ' = '{$this->tablePrefix}' || asq.sequence_name
+				AND asq.sequence_owner = upper('{$this->dbName}')
+				AND atc.owner = upper('{$this->dbName}')" );
+
+			while ( ( $row = $result->fetchRow() ) !== false ) {
+				$this->sequenceData[$row[1]] = [
+					'sequence' => $row[0],
+					'column' => $row[2]
+				];
+			}
+		}
+		$table = strtolower( $this->removeIdentifierQuotes( $this->tableName( $table ) ) );
+
+		return ( isset( $this->sequenceData[$table] ) ) ? $this->sequenceData[$table] : false;
+	}
+
+	/**
+	 * Returns the size of a text field, or -1 for "unlimited"
+	 *
+	 * @param string $table
+	 * @param string $field
+	 * @return mixed
+	 */
+	function textFieldSize( $table, $field ) {
+		$fieldInfoData = $this->fieldInfo( $table, $field );
+
+		return $fieldInfoData->maxLength();
+	}
+
+	function limitResult( $sql, $limit, $offset = false ) {
+		if ( $offset === false ) {
+			$offset = 0;
+		}
+
+		return "SELECT * FROM ($sql) WHERE rownum >= (1 + $offset) AND rownum < (1 + $limit + $offset)";
+	}
+
+	function encodeBlob( $b ) {
+		return new Blob( $b );
+	}
+
+	function decodeBlob( $b ) {
+		if ( $b instanceof Blob ) {
+			$b = $b->fetch();
+		}
+
+		return $b;
+	}
+
+	function unionQueries( $sqls, $all ) {
+		$glue = ' UNION ALL ';
+
+		return 'SELECT * ' . ( $all ? '' : '/* UNION_UNIQUE */ ' ) .
+			'FROM (' . implode( $glue, $sqls ) . ')';
+	}
+
+	function wasDeadlock() {
+		return $this->lastErrno() == 'OCI-00060';
+	}
+
+	function duplicateTableStructure( $oldName, $newName, $temporary = false,
+		$fname = __METHOD__
+	) {
+		$temporary = $temporary ? 'TRUE' : 'FALSE';
+
+		$newName = strtoupper( $newName );
+		$oldName = strtoupper( $oldName );
+
+		$tabName = substr( $newName, strlen( $this->tablePrefix ) );
+		$oldPrefix = substr( $oldName, 0, strlen( $oldName ) - strlen( $tabName ) );
+		$newPrefix = strtoupper( $this->tablePrefix );
+
+		return $this->doQuery( "BEGIN DUPLICATE_TABLE( '$tabName', " .
+			"'$oldPrefix', '$newPrefix', $temporary ); END;" );
+	}
+
+	function listTables( $prefix = null, $fname = __METHOD__ ) {
+		$listWhere = '';
+		if ( !empty( $prefix ) ) {
+			$listWhere = ' AND table_name LIKE \'' . strtoupper( $prefix ) . '%\'';
+		}
+
+		$owner = strtoupper( $this->dbName );
+		$result = $this->doQuery( "SELECT table_name FROM all_tables " .
+			"WHERE owner='$owner' AND table_name NOT LIKE '%!_IDX\$_' ESCAPE '!' $listWhere" );
+
+		// dirty code ... i know
+		$endArray = [];
+		$endArray[] = strtoupper( $prefix . 'MWUSER' );
+		$endArray[] = strtoupper( $prefix . 'PAGE' );
+		$endArray[] = strtoupper( $prefix . 'IMAGE' );
+		$fixedOrderTabs = $endArray;
+		while ( ( $row = $result->fetchRow() ) !== false ) {
+			if ( !in_array( $row['table_name'], $fixedOrderTabs ) ) {
+				$endArray[] = $row['table_name'];
+			}
+		}
+
+		return $endArray;
+	}
+
+	public function dropTable( $tableName, $fName = __METHOD__ ) {
+		$tableName = $this->tableName( $tableName );
+		if ( !$this->tableExists( $tableName ) ) {
+			return false;
+		}
+
+		return $this->doQuery( "DROP TABLE $tableName CASCADE CONSTRAINTS PURGE" );
+	}
+
+	function timestamp( $ts = 0 ) {
+		return wfTimestamp( TS_ORACLE, $ts );
+	}
+
+	/**
+	 * Return aggregated value function call
+	 *
+	 * @param array $valuedata
+	 * @param string $valuename
+	 * @return mixed
+	 */
+	public function aggregateValue( $valuedata, $valuename = 'value' ) {
+		return $valuedata;
+	}
+
+	/**
+	 * @return string Wikitext of a link to the server software's web site
+	 */
+	public function getSoftwareLink() {
+		return '[{{int:version-db-oracle-url}} Oracle]';
+	}
+
+	/**
+	 * @return string Version information from the database
+	 */
+	function getServerVersion() {
+		// better version number, fallback on driver
+		$rset = $this->doQuery(
+			'SELECT version FROM product_component_version ' .
+				'WHERE UPPER(product) LIKE \'ORACLE DATABASE%\''
+		);
+		$row = $rset->fetchRow();
+		if ( !$row ) {
+			return oci_server_version( $this->conn );
+		}
+
+		return $row['version'];
+	}
+
+	/**
+	 * Query whether a given index exists
+	 * @param string $table
+	 * @param string $index
+	 * @param string $fname
+	 * @return bool
+	 */
+	function indexExists( $table, $index, $fname = __METHOD__ ) {
+		$table = $this->tableName( $table );
+		$table = strtoupper( $this->removeIdentifierQuotes( $table ) );
+		$index = strtoupper( $index );
+		$owner = strtoupper( $this->dbName );
+		$sql = "SELECT 1 FROM all_indexes WHERE owner='$owner' AND index_name='{$table}_{$index}'";
+		$res = $this->doQuery( $sql );
+		if ( $res ) {
+			$count = $res->numRows();
+			$res->free();
+		} else {
+			$count = 0;
+		}
+
+		return $count != 0;
+	}
+
+	/**
+	 * Query whether a given table exists (in the given schema, or the default mw one if not given)
+	 * @param string $table
+	 * @param string $fname
+	 * @return bool
+	 */
+	function tableExists( $table, $fname = __METHOD__ ) {
+		$table = $this->tableName( $table );
+		$table = $this->addQuotes( strtoupper( $this->removeIdentifierQuotes( $table ) ) );
+		$owner = $this->addQuotes( strtoupper( $this->dbName ) );
+		$sql = "SELECT 1 FROM all_tables WHERE owner=$owner AND table_name=$table";
+		$res = $this->doQuery( $sql );
+		if ( $res && $res->numRows() > 0 ) {
+			$exists = true;
+		} else {
+			$exists = false;
+		}
+
+		$res->free();
+
+		return $exists;
+	}
+
+	/**
+	 * Function translates mysql_fetch_field() functionality on ORACLE.
+	 * Caching is present for reducing query time.
+	 * For internal calls. Use fieldInfo for normal usage.
+	 * Returns false if the field doesn't exist
+	 *
+	 * @param array|string $table
+	 * @param string $field
+	 * @return ORAField|ORAResult|false
+	 */
+	private function fieldInfoMulti( $table, $field ) {
+		$field = strtoupper( $field );
+		if ( is_array( $table ) ) {
+			$table = array_map( [ $this, 'tableNameInternal' ], $table );
+			$tableWhere = 'IN (';
+			foreach ( $table as &$singleTable ) {
+				$singleTable = $this->removeIdentifierQuotes( $singleTable );
+				if ( isset( $this->mFieldInfoCache["$singleTable.$field"] ) ) {
+					return $this->mFieldInfoCache["$singleTable.$field"];
+				}
+				$tableWhere .= '\'' . $singleTable . '\',';
+			}
+			$tableWhere = rtrim( $tableWhere, ',' ) . ')';
+		} else {
+			$table = $this->removeIdentifierQuotes( $this->tableNameInternal( $table ) );
+			if ( isset( $this->mFieldInfoCache["$table.$field"] ) ) {
+				return $this->mFieldInfoCache["$table.$field"];
+			}
+			$tableWhere = '= \'' . $table . '\'';
+		}
+
+		$fieldInfoStmt = oci_parse(
+			$this->conn,
+			'SELECT * FROM wiki_field_info_full WHERE table_name ' .
+				$tableWhere . ' and column_name = \'' . $field . '\''
+		);
+		if ( oci_execute( $fieldInfoStmt, $this->execFlags() ) === false ) {
+			$e = oci_error( $fieldInfoStmt );
+			$this->reportQueryError( $e['message'], $e['code'], 'fieldInfo QUERY', __METHOD__ );
+
+			return false;
+		}
+		$res = new ORAResult( $this, $fieldInfoStmt );
+		if ( $res->numRows() == 0 ) {
+			if ( is_array( $table ) ) {
+				foreach ( $table as &$singleTable ) {
+					$this->mFieldInfoCache["$singleTable.$field"] = false;
+				}
+			} else {
+				$this->mFieldInfoCache["$table.$field"] = false;
+			}
+			$fieldInfoTemp = null;
+		} else {
+			$fieldInfoTemp = new ORAField( $res->fetchRow() );
+			$table = $fieldInfoTemp->tableName();
+			$this->mFieldInfoCache["$table.$field"] = $fieldInfoTemp;
+		}
+		$res->free();
+
+		return $fieldInfoTemp;
+	}
+
+	/**
+	 * @throws DBUnexpectedError
+	 * @param string $table
+	 * @param string $field
+	 * @return ORAField
+	 */
+	function fieldInfo( $table, $field ) {
+		if ( is_array( $table ) ) {
+			throw new DBUnexpectedError( $this, 'DatabaseOracle::fieldInfo called with table array!' );
+		}
+
+		return $this->fieldInfoMulti( $table, $field );
+	}
+
+	protected function doBegin( $fname = __METHOD__ ) {
+		$this->trxLevel = 1;
+		$this->doQuery( 'SET CONSTRAINTS ALL DEFERRED' );
+	}
+
+	protected function doCommit( $fname = __METHOD__ ) {
+		if ( $this->trxLevel ) {
+			$ret = oci_commit( $this->conn );
+			if ( !$ret ) {
+				throw new DBUnexpectedError( $this, $this->lastError() );
+			}
+			$this->trxLevel = 0;
+			$this->doQuery( 'SET CONSTRAINTS ALL IMMEDIATE' );
+		}
+	}
+
+	protected function doRollback( $fname = __METHOD__ ) {
+		if ( $this->trxLevel ) {
+			oci_rollback( $this->conn );
+			$this->trxLevel = 0;
+			$this->doQuery( 'SET CONSTRAINTS ALL IMMEDIATE' );
+		}
+	}
+
+	function sourceStream(
+		$fp,
+		callable $lineCallback = null,
+		callable $resultCallback = null,
+		$fname = __METHOD__, callable $inputCallback = null
+	) {
+		$cmd = '';
+		$done = false;
+		$dollarquote = false;
+
+		$replacements = [];
+		// Defines must comply with ^define\s*([^\s=]*)\s*=\s?'\{\$([^\}]*)\}';
+		while ( !feof( $fp ) ) {
+			if ( $lineCallback ) {
+				call_user_func( $lineCallback );
+			}
+			$line = trim( fgets( $fp, 1024 ) );
+			$sl = strlen( $line ) - 1;
+
+			if ( $sl < 0 ) {
+				continue;
+			}
+			if ( '-' == $line[0] && '-' == $line[1] ) {
+				continue;
+			}
+
+			// Allow dollar quoting for function declarations
+			if ( substr( $line, 0, 8 ) == '/*$mw$*/' ) {
+				if ( $dollarquote ) {
+					$dollarquote = false;
+					$line = str_replace( '/*$mw$*/', '', $line ); // remove dollarquotes
+					$done = true;
+				} else {
+					$dollarquote = true;
+				}
+			} elseif ( !$dollarquote ) {
+				if ( ';' == $line[$sl] && ( $sl < 2 || ';' != $line[$sl - 1] ) ) {
+					$done = true;
+					$line = substr( $line, 0, $sl );
+				}
+			}
+
+			if ( $cmd != '' ) {
+				$cmd .= ' ';
+			}
+			$cmd .= "$line\n";
+
+			if ( $done ) {
+				$cmd = str_replace( ';;', ";", $cmd );
+				if ( strtolower( substr( $cmd, 0, 6 ) ) == 'define' ) {
+					if ( preg_match( '/^define\s*([^\s=]*)\s*=\s*\'\{\$([^\}]*)\}\'/', $cmd, $defines ) ) {
+						$replacements[$defines[2]] = $defines[1];
+					}
+				} else {
+					foreach ( $replacements as $mwVar => $scVar ) {
+						$cmd = str_replace( '&' . $scVar . '.', '`{$' . $mwVar . '}`', $cmd );
+					}
+
+					$cmd = $this->replaceVars( $cmd );
+					if ( $inputCallback ) {
+						call_user_func( $inputCallback, $cmd );
+					}
+					$res = $this->doQuery( $cmd );
+					if ( $resultCallback ) {
+						call_user_func( $resultCallback, $res, $this );
+					}
+
+					if ( false === $res ) {
+						$err = $this->lastError();
+
+						return "Query \"{$cmd}\" failed with error code \"$err\".\n";
+					}
+				}
+
+				$cmd = '';
+				$done = false;
+			}
+		}
+
+		return true;
+	}
+
+	function selectDB( $db ) {
+		$this->dbName = $db;
+		if ( $db == null || $db == $this->user ) {
+			return true;
+		}
+		$sql = 'ALTER SESSION SET CURRENT_SCHEMA=' . strtoupper( $db );
+		$stmt = oci_parse( $this->conn, $sql );
+		Wikimedia\suppressWarnings();
+		$success = oci_execute( $stmt );
+		Wikimedia\restoreWarnings();
+		if ( !$success ) {
+			$e = oci_error( $stmt );
+			if ( $e['code'] != '1435' ) {
+				$this->reportQueryError( $e['message'], $e['code'], $sql, __METHOD__ );
+			}
+
+			return false;
+		}
+
+		return true;
+	}
+
+	function strencode( $s ) {
+		return str_replace( "'", "''", $s );
+	}
+
+	function addQuotes( $s ) {
+		global $wgContLang;
+		if ( isset( $wgContLang->mLoaded ) && $wgContLang->mLoaded ) {
+			$s = $wgContLang->checkTitleEncoding( $s );
+		}
+
+		return "'" . $this->strencode( $s ) . "'";
+	}
+
+	public function addIdentifierQuotes( $s ) {
+		if ( !$this->getFlag( DBO_DDLMODE ) ) {
+			$s = '/*Q*/' . $s;
+		}
+
+		return $s;
+	}
+
+	public function removeIdentifierQuotes( $s ) {
+		return strpos( $s, '/*Q*/' ) === false ? $s : substr( $s, 5 );
+	}
+
+	public function isQuotedIdentifier( $s ) {
+		return strpos( $s, '/*Q*/' ) !== false;
+	}
+
+	private function wrapFieldForWhere( $table, &$col, &$val ) {
+		global $wgContLang;
+
+		$col_info = $this->fieldInfoMulti( $table, $col );
+		$col_type = $col_info != false ? $col_info->type() : 'CONSTANT';
+		if ( $col_type == 'CLOB' ) {
+			$col = 'TO_CHAR(' . $col . ')';
+			$val = $wgContLang->checkTitleEncoding( $val );
+		} elseif ( $col_type == 'VARCHAR2' ) {
+			$val = $wgContLang->checkTitleEncoding( $val );
+		}
+	}
+
+	private function wrapConditionsForWhere( $table, $conds, $parentCol = null ) {
+		$conds2 = [];
+		foreach ( $conds as $col => $val ) {
+			if ( is_array( $val ) ) {
+				$conds2[$col] = $this->wrapConditionsForWhere( $table, $val, $col );
+			} else {
+				if ( is_numeric( $col ) && $parentCol != null ) {
+					$this->wrapFieldForWhere( $table, $parentCol, $val );
+				} else {
+					$this->wrapFieldForWhere( $table, $col, $val );
+				}
+				$conds2[$col] = $val;
+			}
+		}
+
+		return $conds2;
+	}
+
+	function selectRow( $table, $vars, $conds, $fname = __METHOD__,
+		$options = [], $join_conds = []
+	) {
+		if ( is_array( $conds ) ) {
+			$conds = $this->wrapConditionsForWhere( $table, $conds );
+		}
+
+		return parent::selectRow( $table, $vars, $conds, $fname, $options, $join_conds );
+	}
+
+	/**
+	 * Returns an optional USE INDEX clause to go after the table, and a
+	 * string to go at the end of the query
+	 *
+	 * @param array $options An associative array of options to be turned into
+	 *   an SQL query, valid keys are listed in the function.
+	 * @return array
+	 */
+	function makeSelectOptions( $options ) {
+		$preLimitTail = $postLimitTail = '';
+		$startOpts = '';
+
+		$noKeyOptions = [];
+		foreach ( $options as $key => $option ) {
+			if ( is_numeric( $key ) ) {
+				$noKeyOptions[$option] = true;
+			}
+		}
+
+		$preLimitTail .= $this->makeGroupByWithHaving( $options );
+
+		$preLimitTail .= $this->makeOrderBy( $options );
+
+		if ( isset( $noKeyOptions['FOR UPDATE'] ) ) {
+			$postLimitTail .= ' FOR UPDATE';
+		}
+
+		if ( isset( $noKeyOptions['DISTINCT'] ) || isset( $noKeyOptions['DISTINCTROW'] ) ) {
+			$startOpts .= 'DISTINCT';
+		}
+
+		if ( isset( $options['USE INDEX'] ) && !is_array( $options['USE INDEX'] ) ) {
+			$useIndex = $this->useIndexClause( $options['USE INDEX'] );
+		} else {
+			$useIndex = '';
+		}
+
+		if ( isset( $options['IGNORE INDEX'] ) && !is_array( $options['IGNORE INDEX'] ) ) {
+			$ignoreIndex = $this->ignoreIndexClause( $options['IGNORE INDEX'] );
+		} else {
+			$ignoreIndex = '';
+		}
+
+		return [ $startOpts, $useIndex, $preLimitTail, $postLimitTail, $ignoreIndex ];
+	}
+
+	public function delete( $table, $conds, $fname = __METHOD__ ) {
+		global $wgActorTableSchemaMigrationStage;
+
+		if ( is_array( $conds ) ) {
+			$conds = $this->wrapConditionsForWhere( $table, $conds );
+		}
+		// a hack for deleting pages, users and images (which have non-nullable FKs)
+		// all deletions on these tables have transactions so final failure rollbacks these updates
+		// @todo: Normalize the schema to match MySQL, no special FKs and such
+		$table = $this->tableName( $table );
+		if ( $table == $this->tableName( 'user' ) && $wgActorTableSchemaMigrationStage < MIGRATION_NEW ) {
+			$this->update( 'archive', [ 'ar_user' => 0 ],
+				[ 'ar_user' => $conds['user_id'] ], $fname );
+			$this->update( 'ipblocks', [ 'ipb_user' => 0 ],
+				[ 'ipb_user' => $conds['user_id'] ], $fname );
+			$this->update( 'image', [ 'img_user' => 0 ],
+				[ 'img_user' => $conds['user_id'] ], $fname );
+			$this->update( 'oldimage', [ 'oi_user' => 0 ],
+				[ 'oi_user' => $conds['user_id'] ], $fname );
+			$this->update( 'filearchive', [ 'fa_deleted_user' => 0 ],
+				[ 'fa_deleted_user' => $conds['user_id'] ], $fname );
+			$this->update( 'filearchive', [ 'fa_user' => 0 ],
+				[ 'fa_user' => $conds['user_id'] ], $fname );
+			$this->update( 'uploadstash', [ 'us_user' => 0 ],
+				[ 'us_user' => $conds['user_id'] ], $fname );
+			$this->update( 'recentchanges', [ 'rc_user' => 0 ],
+				[ 'rc_user' => $conds['user_id'] ], $fname );
+			$this->update( 'logging', [ 'log_user' => 0 ],
+				[ 'log_user' => $conds['user_id'] ], $fname );
+		} elseif ( $table == $this->tableName( 'image' ) ) {
+			$this->update( 'oldimage', [ 'oi_name' => 0 ],
+				[ 'oi_name' => $conds['img_name'] ], $fname );
+		}
+
+		return parent::delete( $table, $conds, $fname );
+	}
+
+	/**
+	 * @param string $table
+	 * @param array $values
+	 * @param array $conds
+	 * @param string $fname
+	 * @param array $options
+	 * @return bool
+	 * @throws DBUnexpectedError
+	 */
+	function update( $table, $values, $conds, $fname = __METHOD__, $options = [] ) {
+		global $wgContLang;
+
+		$table = $this->tableName( $table );
+		$opts = $this->makeUpdateOptions( $options );
+		$sql = "UPDATE $opts $table SET ";
+
+		$first = true;
+		foreach ( $values as $col => &$val ) {
+			$sqlSet = $this->fieldBindStatement( $table, $col, $val, true );
+
+			if ( !$first ) {
+				$sqlSet = ', ' . $sqlSet;
+			} else {
+				$first = false;
+			}
+			$sql .= $sqlSet;
+		}
+
+		if ( $conds !== [] && $conds !== '*' ) {
+			$conds = $this->wrapConditionsForWhere( $table, $conds );
+			$sql .= ' WHERE ' . $this->makeList( $conds, LIST_AND );
+		}
+
+		$this->mLastResult = $stmt = oci_parse( $this->conn, $sql );
+		if ( $stmt === false ) {
+			$e = oci_error( $this->conn );
+			$this->reportQueryError( $e['message'], $e['code'], $sql, __METHOD__ );
+
+			return false;
+		}
+		foreach ( $values as $col => &$val ) {
+			$col_info = $this->fieldInfoMulti( $table, $col );
+			$col_type = $col_info != false ? $col_info->type() : 'CONSTANT';
+
+			if ( $val === null ) {
+				// do nothing ... null was inserted in statement creation
+			} elseif ( $col_type != 'BLOB' && $col_type != 'CLOB' ) {
+				if ( is_object( $val ) ) {
+					$val = $val->getData();
+				}
+
+				if ( preg_match( '/^timestamp.*/i', $col_type ) == 1 && strtolower( $val ) == 'infinity' ) {
+					$val = '31-12-2030 12:00:00.000000';
+				}
+
+				$val = ( $wgContLang != null ) ? $wgContLang->checkTitleEncoding( $val ) : $val;
+				if ( oci_bind_by_name( $stmt, ":$col", $val ) === false ) {
+					$e = oci_error( $stmt );
+					$this->reportQueryError( $e['message'], $e['code'], $sql, __METHOD__ );
+
+					return false;
+				}
+			} else {
+				/** @var OCI_Lob[] $lob */
+				$lob[$col] = oci_new_descriptor( $this->conn, OCI_D_LOB );
+				if ( $lob[$col] === false ) {
+					$e = oci_error( $stmt );
+					throw new DBUnexpectedError( $this, "Cannot create LOB descriptor: " . $e['message'] );
+				}
+
+				if ( is_object( $val ) ) {
+					$val = $val->getData();
+				}
+
+				if ( $col_type == 'BLOB' ) {
+					$lob[$col]->writeTemporary( $val );
+					oci_bind_by_name( $stmt, ":$col", $lob[$col], -1, SQLT_BLOB );
+				} else {
+					$lob[$col]->writeTemporary( $val );
+					oci_bind_by_name( $stmt, ":$col", $lob[$col], -1, OCI_B_CLOB );
+				}
+			}
+		}
+
+		Wikimedia\suppressWarnings();
+
+		if ( oci_execute( $stmt, $this->execFlags() ) === false ) {
+			$e = oci_error( $stmt );
+			if ( !$this->ignoreDupValOnIndex || $e['code'] != '1' ) {
+				$this->reportQueryError( $e['message'], $e['code'], $sql, __METHOD__ );
+
+				return false;
+			} else {
+				$this->mAffectedRows = oci_num_rows( $stmt );
+			}
+		} else {
+			$this->mAffectedRows = oci_num_rows( $stmt );
+		}
+
+		Wikimedia\restoreWarnings();
+
+		if ( isset( $lob ) ) {
+			foreach ( $lob as $lob_v ) {
+				$lob_v->free();
+			}
+		}
+
+		if ( !$this->trxLevel ) {
+			oci_commit( $this->conn );
+		}
+
+		return oci_free_statement( $stmt );
+	}
+
+	function bitNot( $field ) {
+		// expecting bit-fields smaller than 4bytes
+		return 'BITNOT(' . $field . ')';
+	}
+
+	function bitAnd( $fieldLeft, $fieldRight ) {
+		return 'BITAND(' . $fieldLeft . ', ' . $fieldRight . ')';
+	}
+
+	function bitOr( $fieldLeft, $fieldRight ) {
+		return 'BITOR(' . $fieldLeft . ', ' . $fieldRight . ')';
+	}
+
+	function getDBname() {
+		return $this->dbName;
+	}
+
+	function getServer() {
+		return $this->server;
+	}
+
+	public function buildGroupConcatField(
+		$delim, $table, $field, $conds = '', $join_conds = []
+	) {
+		$fld = "LISTAGG($field," . $this->addQuotes( $delim ) . ") WITHIN GROUP (ORDER BY $field)";
+
+		return '(' . $this->selectSQLText( $table, $fld, $conds, null, [], $join_conds ) . ')';
+	}
+
+	public function buildSubstring( $input, $startPosition, $length = null ) {
+		$this->assertBuildSubstringParams( $startPosition, $length );
+		$params = [ $input, $startPosition ];
+		if ( $length !== null ) {
+			$params[] = $length;
+		}
+		return 'SUBSTR(' . implode( ',', $params ) . ')';
+	}
+
+	/**
+	 * @param string $field Field or column to cast
+	 * @return string
+	 * @since 1.28
+	 */
+	public function buildStringCast( $field ) {
+		return 'CAST ( ' . $field . ' AS VARCHAR2 )';
+	}
+
+	public function getInfinity() {
+		return '31-12-2030 12:00:00.000000';
+	}
+}
diff --git a/www/wiki/includes/db/MWLBFactory.php b/www/wiki/includes/db/MWLBFactory.php
new file mode 100644
index 00000000..79f787db
--- /dev/null
+++ b/www/wiki/includes/db/MWLBFactory.php
@@ -0,0 +1,252 @@
+<?php
+/**
+ * Generator of database load balancing objects.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ * http://www.gnu.org/copyleft/gpl.html
+ *
+ * @file
+ * @ingroup Database
+ */
+
+use MediaWiki\Logger\LoggerFactory;
+use MediaWiki\MediaWikiServices;
+use Wikimedia\Rdbms\LBFactory;
+use Wikimedia\Rdbms\DatabaseDomain;
+
+/**
+ * MediaWiki-specific class for generating database load balancers
+ * @ingroup Database
+ */
+abstract class MWLBFactory {
+
+	/** @var array Cache of already-logged deprecation messages */
+	private static $loggedDeprecations = [];
+
+	/**
+	 * @param array $lbConf Config for LBFactory::__construct()
+	 * @param Config $mainConfig Main config object from MediaWikiServices
+	 * @param ConfiguredReadOnlyMode $readOnlyMode
+	 * @return array
+	 */
+	public static function applyDefaultConfig( array $lbConf, Config $mainConfig,
+		ConfiguredReadOnlyMode $readOnlyMode
+	) {
+		global $wgCommandLineMode;
+
+		static $typesWithSchema = [ 'postgres', 'msssql' ];
+
+		$lbConf += [
+			'localDomain' => new DatabaseDomain(
+				$mainConfig->get( 'DBname' ),
+				$mainConfig->get( 'DBmwschema' ),
+				$mainConfig->get( 'DBprefix' )
+			),
+			'profiler' => Profiler::instance(),
+			'trxProfiler' => Profiler::instance()->getTransactionProfiler(),
+			'replLogger' => LoggerFactory::getInstance( 'DBReplication' ),
+			'queryLogger' => LoggerFactory::getInstance( 'DBQuery' ),
+			'connLogger' => LoggerFactory::getInstance( 'DBConnection' ),
+			'perfLogger' => LoggerFactory::getInstance( 'DBPerformance' ),
+			'errorLogger' => [ MWExceptionHandler::class, 'logException' ],
+			'deprecationLogger' => [ static::class, 'logDeprecation' ],
+			'cliMode' => $wgCommandLineMode,
+			'hostname' => wfHostname(),
+			'readOnlyReason' => $readOnlyMode->getReason(),
+		];
+
+		// When making changes here, remember to also specify MediaWiki-specific options
+		// for Database classes in the relevant Installer subclass.
+		// Such as MysqlInstaller::openConnection and PostgresInstaller::openConnectionWithParams.
+		if ( $lbConf['class'] === Wikimedia\Rdbms\LBFactorySimple::class ) {
+			if ( isset( $lbConf['servers'] ) ) {
+				// Server array is already explicitly configured; leave alone
+			} elseif ( is_array( $mainConfig->get( 'DBservers' ) ) ) {
+				foreach ( $mainConfig->get( 'DBservers' ) as $i => $server ) {
+					if ( $server['type'] === 'sqlite' ) {
+						$server += [ 'dbDirectory' => $mainConfig->get( 'SQLiteDataDir' ) ];
+					} elseif ( $server['type'] === 'postgres' ) {
+						$server += [
+							'port' => $mainConfig->get( 'DBport' ),
+							// Work around the reserved word usage in MediaWiki schema
+							'keywordTableMap' => [ 'user' => 'mwuser', 'text' => 'pagecontent' ]
+						];
+					} elseif ( $server['type'] === 'mssql' ) {
+						$server += [
+							'port' => $mainConfig->get( 'DBport' ),
+							'useWindowsAuth' => $mainConfig->get( 'DBWindowsAuthentication' )
+						];
+					}
+
+					if ( in_array( $server['type'], $typesWithSchema, true ) ) {
+						$server += [ 'schema' => $mainConfig->get( 'DBmwschema' ) ];
+					}
+
+					$server += [
+						'tablePrefix' => $mainConfig->get( 'DBprefix' ),
+						'flags' => DBO_DEFAULT,
+						'sqlMode' => $mainConfig->get( 'SQLMode' ),
+						'utf8Mode' => $mainConfig->get( 'DBmysql5' )
+					];
+
+					$lbConf['servers'][$i] = $server;
+				}
+			} else {
+				$flags = DBO_DEFAULT;
+				$flags |= $mainConfig->get( 'DebugDumpSql' ) ? DBO_DEBUG : 0;
+				$flags |= $mainConfig->get( 'DBssl' ) ? DBO_SSL : 0;
+				$flags |= $mainConfig->get( 'DBcompress' ) ? DBO_COMPRESS : 0;
+				$server = [
+					'host' => $mainConfig->get( 'DBserver' ),
+					'user' => $mainConfig->get( 'DBuser' ),
+					'password' => $mainConfig->get( 'DBpassword' ),
+					'dbname' => $mainConfig->get( 'DBname' ),
+					'tablePrefix' => $mainConfig->get( 'DBprefix' ),
+					'type' => $mainConfig->get( 'DBtype' ),
+					'load' => 1,
+					'flags' => $flags,
+					'sqlMode' => $mainConfig->get( 'SQLMode' ),
+					'utf8Mode' => $mainConfig->get( 'DBmysql5' )
+				];
+				if ( in_array( $server['type'], $typesWithSchema, true ) ) {
+					$server += [ 'schema' => $mainConfig->get( 'DBmwschema' ) ];
+				}
+				if ( $server['type'] === 'sqlite' ) {
+					$server[ 'dbDirectory'] = $mainConfig->get( 'SQLiteDataDir' );
+				} elseif ( $server['type'] === 'postgres' ) {
+					$server['port'] = $mainConfig->get( 'DBport' );
+					// Work around the reserved word usage in MediaWiki schema
+					$server['keywordTableMap'] = [ 'user' => 'mwuser', 'text' => 'pagecontent' ];
+				} elseif ( $server['type'] === 'mssql' ) {
+					$server['port'] = $mainConfig->get( 'DBport' );
+					$server['useWindowsAuth'] = $mainConfig->get( 'DBWindowsAuthentication' );
+				}
+				$lbConf['servers'] = [ $server ];
+			}
+			if ( !isset( $lbConf['externalClusters'] ) ) {
+				$lbConf['externalClusters'] = $mainConfig->get( 'ExternalServers' );
+			}
+		} elseif ( $lbConf['class'] === Wikimedia\Rdbms\LBFactoryMulti::class ) {
+			if ( isset( $lbConf['serverTemplate'] ) ) {
+				if ( in_array( $lbConf['serverTemplate']['type'], $typesWithSchema, true ) ) {
+					$lbConf['serverTemplate']['schema'] = $mainConfig->get( 'DBmwschema' );
+				}
+				$lbConf['serverTemplate']['sqlMode'] = $mainConfig->get( 'SQLMode' );
+				$lbConf['serverTemplate']['utf8Mode'] = $mainConfig->get( 'DBmysql5' );
+			}
+		}
+
+		$services = MediaWikiServices::getInstance();
+
+		// Use APC/memcached style caching, but avoids loops with CACHE_DB (T141804)
+		$sCache = $services->getLocalServerObjectCache();
+		if ( $sCache->getQoS( $sCache::ATTR_EMULATION ) > $sCache::QOS_EMULATION_SQL ) {
+			$lbConf['srvCache'] = $sCache;
+		}
+		$mStash = $services->getMainObjectStash();
+		if ( $mStash->getQoS( $mStash::ATTR_EMULATION ) > $mStash::QOS_EMULATION_SQL ) {
+			$lbConf['memStash'] = $mStash;
+		}
+		$wCache = $services->getMainWANObjectCache();
+		if ( $wCache->getQoS( $wCache::ATTR_EMULATION ) > $wCache::QOS_EMULATION_SQL ) {
+			$lbConf['wanCache'] = $wCache;
+		}
+
+		return $lbConf;
+	}
+
+	/**
+	 * Returns the LBFactory class to use and the load balancer configuration.
+	 *
+	 * @todo instead of this, use a ServiceContainer for managing the different implementations.
+	 *
+	 * @param array $config (e.g. $wgLBFactoryConf)
+	 * @return string Class name
+	 */
+	public static function getLBFactoryClass( array $config ) {
+		// For configuration backward compatibility after removing
+		// underscores from class names in MediaWiki 1.23.
+		$bcClasses = [
+			'LBFactory_Simple' => 'LBFactorySimple',
+			'LBFactory_Single' => 'LBFactorySingle',
+			'LBFactory_Multi' => 'LBFactoryMulti'
+		];
+
+		$class = $config['class'];
+
+		if ( isset( $bcClasses[$class] ) ) {
+			$class = $bcClasses[$class];
+			wfDeprecated(
+				'$wgLBFactoryConf must be updated. See RELEASE-NOTES for details',
+				'1.23'
+			);
+		}
+
+		// For configuration backward compatibility after moving classes to namespaces (1.29)
+		$compat = [
+			'LBFactorySingle' => Wikimedia\Rdbms\LBFactorySingle::class,
+			'LBFactorySimple' => Wikimedia\Rdbms\LBFactorySimple::class,
+			'LBFactoryMulti' => Wikimedia\Rdbms\LBFactoryMulti::class
+		];
+
+		if ( isset( $compat[$class] ) ) {
+			$class = $compat[$class];
+		}
+
+		return $class;
+	}
+
+	public static function setSchemaAliases( LBFactory $lbFactory, Config $config ) {
+		if ( $config->get( 'DBtype' ) === 'mysql' ) {
+			/**
+			 * When SQLite indexes were introduced in r45764, it was noted that
+			 * SQLite requires index names to be unique within the whole database,
+			 * not just within a schema. As discussed in CR r45819, to avoid the
+			 * need for a schema change on existing installations, the indexes
+			 * were implicitly mapped from the new names to the old names.
+			 *
+			 * This mapping can be removed if DB patches are introduced to alter
+			 * the relevant tables in existing installations. Note that because
+			 * this index mapping applies to table creation, even new installations
+			 * of MySQL have the old names (except for installations created during
+			 * a period where this mapping was inappropriately removed, see
+			 * T154872).
+			 */
+			$lbFactory->setIndexAliases( [
+				'ar_usertext_timestamp' => 'usertext_timestamp',
+				'un_user_id' => 'user_id',
+				'un_user_ip' => 'user_ip',
+			] );
+		}
+	}
+
+	/**
+	 * Log a database deprecation warning
+	 * @param string $msg Deprecation message
+	 */
+	public static function logDeprecation( $msg ) {
+		global $wgDevelopmentWarnings;
+
+		if ( isset( self::$loggedDeprecations[$msg] ) ) {
+			return;
+		}
+		self::$loggedDeprecations[$msg] = true;
+
+		if ( $wgDevelopmentWarnings ) {
+			trigger_error( $msg, E_USER_DEPRECATED );
+		}
+		wfDebugLog( 'deprecated', $msg, 'private' );
+	}
+}
diff --git a/www/wiki/includes/db/ORAField.php b/www/wiki/includes/db/ORAField.php
new file mode 100644
index 00000000..df310003
--- /dev/null
+++ b/www/wiki/includes/db/ORAField.php
@@ -0,0 +1,53 @@
+<?php
+
+use Wikimedia\Rdbms\Field;
+
+class ORAField implements Field {
+	private $name, $tablename, $default, $max_length, $nullable,
+		$is_pk, $is_unique, $is_multiple, $is_key, $type;
+
+	function __construct( $info ) {
+		$this->name = $info['column_name'];
+		$this->tablename = $info['table_name'];
+		$this->default = $info['data_default'];
+		$this->max_length = $info['data_length'];
+		$this->nullable = $info['not_null'];
+		$this->is_pk = isset( $info['prim'] ) && $info['prim'] == 1 ? 1 : 0;
+		$this->is_unique = isset( $info['uniq'] ) && $info['uniq'] == 1 ? 1 : 0;
+		$this->is_multiple = isset( $info['nonuniq'] ) && $info['nonuniq'] == 1 ? 1 : 0;
+		$this->is_key = ( $this->is_pk || $this->is_unique || $this->is_multiple );
+		$this->type = $info['data_type'];
+	}
+
+	function name() {
+		return $this->name;
+	}
+
+	function tableName() {
+		return $this->tablename;
+	}
+
+	function defaultValue() {
+		return $this->default;
+	}
+
+	function maxLength() {
+		return $this->max_length;
+	}
+
+	function isNullable() {
+		return $this->nullable;
+	}
+
+	function isKey() {
+		return $this->is_key;
+	}
+
+	function isMultipleKey() {
+		return $this->is_multiple;
+	}
+
+	function type() {
+		return $this->type;
+	}
+}
diff --git a/www/wiki/includes/db/ORAResult.php b/www/wiki/includes/db/ORAResult.php
new file mode 100644
index 00000000..aafd3861
--- /dev/null
+++ b/www/wiki/includes/db/ORAResult.php
@@ -0,0 +1,110 @@
+<?php
+
+use Wikimedia\Rdbms\IDatabase;
+
+/**
+ * The oci8 extension is fairly weak and doesn't support oci_num_rows, among
+ * other things. We use a wrapper class to handle that and other
+ * Oracle-specific bits, like converting column names back to lowercase.
+ * @ingroup Database
+ */
+class ORAResult {
+	private $rows;
+	private $cursor;
+	private $nrows;
+
+	private $columns = [];
+
+	private function array_unique_md( $array_in ) {
+		$array_out = [];
+		$array_hashes = [];
+
+		foreach ( $array_in as $item ) {
+			$hash = md5( serialize( $item ) );
+			if ( !isset( $array_hashes[$hash] ) ) {
+				$array_hashes[$hash] = $hash;
+				$array_out[] = $item;
+			}
+		}
+
+		return $array_out;
+	}
+
+	/**
+	 * @param IDatabase &$db
+	 * @param resource $stmt A valid OCI statement identifier
+	 * @param bool $unique
+	 */
+	function __construct( &$db, $stmt, $unique = false ) {
+		$this->db =& $db;
+
+		$this->nrows = oci_fetch_all( $stmt, $this->rows, 0, -1, OCI_FETCHSTATEMENT_BY_ROW | OCI_NUM );
+		if ( $this->nrows === false ) {
+			$e = oci_error( $stmt );
+			$db->reportQueryError( $e['message'], $e['code'], '', __METHOD__ );
+			$this->free();
+
+			return;
+		}
+
+		if ( $unique ) {
+			$this->rows = $this->array_unique_md( $this->rows );
+			$this->nrows = count( $this->rows );
+		}
+
+		if ( $this->nrows > 0 ) {
+			foreach ( $this->rows[0] as $k => $v ) {
+				$this->columns[$k] = strtolower( oci_field_name( $stmt, $k + 1 ) );
+			}
+		}
+
+		$this->cursor = 0;
+		oci_free_statement( $stmt );
+	}
+
+	public function free() {
+		unset( $this->db );
+	}
+
+	public function seek( $row ) {
+		$this->cursor = min( $row, $this->nrows );
+	}
+
+	public function numRows() {
+		return $this->nrows;
+	}
+
+	public function numFields() {
+		return count( $this->columns );
+	}
+
+	public function fetchObject() {
+		if ( $this->cursor >= $this->nrows ) {
+			return false;
+		}
+		$row = $this->rows[$this->cursor++];
+		$ret = new stdClass();
+		foreach ( $row as $k => $v ) {
+			$lc = $this->columns[$k];
+			$ret->$lc = $v;
+		}
+
+		return $ret;
+	}
+
+	public function fetchRow() {
+		if ( $this->cursor >= $this->nrows ) {
+			return false;
+		}
+
+		$row = $this->rows[$this->cursor++];
+		$ret = [];
+		foreach ( $row as $k => $v ) {
+			$lc = $this->columns[$k];
+			$ret[$lc] = $v;
+			$ret[$k] = $v;
+		}
+
+		return $ret;
+	}
+}