1.如何限定特定IP訪問(wèn)數(shù)據(jù)庫(kù)可以利用登錄觸發(fā)器、cmgw或者是在$OREACLE_HOME/network/admin下新增一個(gè)protocol.ora文件（有些os可能是. protocol.ora），9i可以直接修改sqlnet.ora：增加如下內(nèi)容：tcp.validnode_checking=yes#答應(yīng)訪問(wèn)的iptcp.inited_nodes=(ip1,ip2,...)#不答應(yīng)訪問(wèn)的iptcp.excluded_nodes=(ip1,ip2,...)2.如何穿過(guò)防火墻連接數(shù)據(jù)庫(kù)這個(gè)問(wèn)題只會(huì)在WIN平臺(tái)出現(xiàn)，UNIX平臺(tái)會(huì)自動(dòng)解決。解決方法：在服務(wù)器端的SQLNET.ORA應(yīng)類(lèi)似SQLNET.AUTHENTICATION_SERVICES= (NTS) NAMES.DirectorY_PATH= (TNSNAMES, ONAMES, HOSTNAME) TRACE_LEVEL_CLIENT = 16 注冊(cè)表的HOME0加[HKEY_LOCAL_MACHINE] USE_SHARED_SOCKET=TRUE3.如何利用hostname方式連接數(shù)據(jù)庫(kù)host name方式只支持tcp/ip協(xié)議的小局域網(wǎng)修改listener.ora中的如下信息(SID_DESC =(GLOBAL_DBNAME = ur_hostname) --你的機(jī)器名(Oracle_HOME = E:oracleora92) --oracle home(SID_NAME = orcl) --sid name)然后在客戶(hù)端的sqlnet.ora中，確保有NAMES.DIRECTORY_PATH= (HOSTNAME)你就可以利用數(shù)據(jù)庫(kù)服務(wù)器的名稱(chēng)訪問(wèn)數(shù)據(jù)庫(kù)了4.dbms_repcat_admin能帶來(lái)什么安全隱患假如一個(gè)用戶(hù)能執(zhí)行dbms_repcat_admin包，將獲得極大的系統(tǒng)權(quán)限。以下情況可能獲得該包的執(zhí)行權(quán)限：1、在sys下grant execute on dbms_repcat_admin to public[user_name]2、用戶(hù)擁有execute any procedure特權(quán)（僅限于9i以下，9i必須顯示授權(quán)）假如用戶(hù)通過(guò)執(zhí)行如下語(yǔ)句：exec sys.dbms_repcat_admin.grant_admin_any_schema('user_name');該用戶(hù)將獲得極大的系統(tǒng)特權(quán)可以從user_sys_privs中獲得具體信息5.在不知道用戶(hù)密碼的時(shí)候，怎么樣跳轉(zhuǎn)到另外一個(gè)用戶(hù)執(zhí)行操作后并不影響該用戶(hù)?我們通過(guò)如下的方法，可以安全使用該用戶(hù)，然后再跳轉(zhuǎn)回來(lái)，在某些時(shí)候比較有用需要Alter user權(quán)限或DBA權(quán)限：SQL> select passWord from dba_users where username='SCOTT';PASSWORD-----------------------------F894844C34402B67SQL> alter user scott identified by lion;User altered.SQL> connect scott/lionConnected.REM Do whatever you like...SQL> connect system/managerConnected.SQL> alter user scott identified by values 'F894844C34402B67';User altered.SQL> connect scott/tigerConnected.6.如何加固你的數(shù)據(jù)庫(kù)要注重以下方面1. 修改sys, system的口令。 2. Lock，修改，刪除默認(rèn)用戶(hù)： dbsnmp,ctxsys等。 3. 把REMOTE_OS_AUTHENT改成False，防止遠(yuǎn)程機(jī)器直接登陸。 4. 把O7_DICTIONARY_AccessIBILITY改成False。 5. 把一些權(quán)限從PUBLIC Role取消掉。 6. 檢查數(shù)據(jù)庫(kù)的數(shù)據(jù)文件的安全性。不要設(shè)置成666之類(lèi)的。檢查其他dba 用戶(hù)。 7. 把一些不需要的服務(wù)（比如FTP, nfs等關(guān)閉掉） 8. 限制數(shù)據(jù)庫(kù)主機(jī)上面的用戶(hù)數(shù)量。 9. 定期檢查Metalink/OTN上面的security Alert。比如： http://otn.oracle.com/deploy/security/alerts.htm10. 把你的數(shù)據(jù)庫(kù)與應(yīng)用放在一個(gè)單獨(dú)的子網(wǎng)中，要不然你的用戶(hù)密碼很輕易被sniffer去。或者采用advance security，對(duì)用戶(hù)登錄加密。 11. 限止只有某些ip才能訪問(wèn)你的數(shù)據(jù)庫(kù)。 12. lsnrctl 要加密碼，要不然別人很輕易從外面關(guān)掉你的listener。 13. 假如可能，不要使用默認(rèn)1521端口7.如何檢查用戶(hù)是否用了默認(rèn)密碼假如使用默認(rèn)密碼，很可能就對(duì)你的數(shù)據(jù)庫(kù)造成一定的安全隱患，那么可以使用如下的查詢(xún)獲得那些用戶(hù)使用默認(rèn)密碼select username 'User(s) with Default Password!' from dba_users where password in ('E066D214D5421CCC', -- dbsnmp '24ABAB8B06281B4C', -- ctxsys '72979A94BAD2AF80', -- mdsys 'C252E8FA117AF049', -- odm 'A7A32CD03D3CE8D5', -- odm_mtr '88A2B2C183431F00', -- ordplugins '7EFA02EC7EA6B86F', -- ordsys '4A3BA55E08595C81', -- outln 'F894844C34402B67', -- scott '3F9FBD883D787341', -- wk_proxy '79DF7A1BD138CF11', -- wk_sys '7C9BA362F8314299', -- wmsys '88D8364765FCE6AF', -- xdb 'F9DA8977092B7B81', -- tracesvr '9300C0977D7DC75E', -- oas_public 'A97282CE3D94E29E', -- websys 'AC9700FD3F1410EB', -- lbacsys 'E7B5D92911C831E1', -- rman 'AC98877DE1297365', -- perfstat '66F4EF5650C20355', -- exfsys '84B8CBCA4D477FA3', -- si_informtn_schema 'D4C5016086B2DC6A', -- sys 'D4DF7931AB130E37') -- system /8.如何修改默認(rèn)的XDB監(jiān)聽(tīng)端口Oracle9i默認(rèn)的XML DB把HTTP的默認(rèn)端口設(shè)為8080，這是一個(gè)太常用的端口了，很多別的WebServer都會(huì)使用這個(gè)端口，假如我們安裝了它，最好修改一下，避免沖突，假如不使用呢，就最好不要安裝提供三種修改的方法1.dbca，選擇你的數(shù)據(jù)庫(kù)，然后Standard Database Features->Customize->Oracle XML DB option，進(jìn)入這個(gè)畫(huà)面你應(yīng)該就知道怎么改了。 2.OEM console，在XML Database 的配置里面修改 3.用oracle提供的包： -- 把HTTP/WEBDAV端口從8080改到8081 SQL> call dbms_xdb.cfg_update(updateXML(dbms_xdb.cfg_get(), '/xdbconfig/sysconfig/protocolconfig/httpconfig/http-port/text()',8081)) / -- 把FTP端口從2100改到2111 SQL> call dbms_xdb.cfg_update(updateXML(dbms_xdb.cfg_get(), '/xdbconfig/sysconfig/protocolconfig/ftpconfig/ftp-port/text()',2111)) / SQL> commit; SQL> exec dbms_xdb.cfg_refresh; -- 檢查修改是否已經(jīng)成功 SQL> select dbms_xdb.cfg_get from dual;9.怎么捕捉用戶(hù)登錄信息，如SID，IP地址等可以利用登錄觸發(fā)器，如CREATE OR REPLACE TRIGGER tr_login_recordAFTER logon ON DATABASEDECLAREmiUserSid NUMBER;mtSession v$session%ROWTYPE;CURSOR cSession(iiUserSid IN NUMBER) ISSELECT * FROM v$sessionWHERE sid=iiUserSid;BEGINSELECT sid INTO miUserSid FROM v$mystat WHERE rownum10.程序報(bào)錯(cuò)ORA-01555: snapshot too old: rollback segment number 148 with name '_SYSSMU148$' too small可以查詢(xún)錯(cuò)誤原因oerr ora 01555得到如下信息01555, 00000, 'snapshot too old: rollback segment number %s with name '%s' too small'// *Cause: rollback records needed by a reader for consistent read are// overwritten by other writers // *Action: If in Automatic Undo Management mode, increase undo_retention//; setting. Otherwise, use larger rollback segments說(shuō)明一個(gè)事務(wù)的執(zhí)行時(shí)長(zhǎng)超過(guò)了系統(tǒng)設(shè)定的最大值.SQL> show parameters undo比如NAME TYPE;;;;;VALUE------------------------------------ ----------- ------------------------------undo_management;;;string;;;AUTOundo_retention;;;;integer;;16200undo_suppress_errors boolean;;FALSEundo_tablespace;;;string;;;UNDOTBS2則說(shuō)明是16200秒.11.假如你要用ultraEdit-32編輯oracle腳本，可以設(shè)置對(duì)要害字不同亮度的顯示。點(diǎn)'advanced'-->'configuration'-->'Syntax Highlighting'-->'open'，然后把下面的代碼追加到最后保存,再重新打開(kāi)ultraEdit，編輯.sql文件就可以看到了。這樣顏色上輕易分辨。方便一些。/L8'sql' Nocase Line Comment = -- Block Comment On = /* Block Comment Off = */ String Chars = ' File Extensions = SQL/Delimiters = ~!%@^&*()-+=/{}[]:;''<> ,;.?/Function String = '%[A-Z _]*[~s]+(*)'/C1 'Keywords'ABORT ACCEPT ACCESS ADD ALL ALTER AND ANY ARRAY ARRAYLEN AS ASC ASSERT ASSIGN AT AUDIT AUTHORIZATION AVGBASE_TABLE BEGIN BETWEEN BINARY_INTEGER BODY BOOLEAN BYCASE CHAR CHAR_BASE CHECK CLOSE CLUSTER CLUSTERS COLAUTH COLUMN COMMENT COMMIT COMPRESS CONNECT CONSTANT CRASH CREATE CURRENT CURRVAL CURSORDATABASE DATA_BASE DATE DBA DEBUGOFF DEBUGON DECLARE DECIMAL DEFAULT DEFINITION DELAY DELETE DESC DIGITS DISPOSE DISTINCT DO DROPELSE ELSIF END ENTRY EXCEPTION EXCEPTION_INIT EXCLUSIVE EXISTS EXITFALSE FETCH FILE FLOAT FOR FORM FROM FUNCTIONGENERIC GOTO GRANT GROUPHAVINGIDENTIFIED IF IMMEDIATE IN INCREMENT INDEX INDEXES INDICATOR INITIAL INSERT INTEGER INTERFACE INTERSECT INTO ISLEVEL LIKE LIMITED LOCK LONG LOOPMAX MAXEXTENTS MIN MINEXTENTS MINUS MISLABEL MOD MODENATURAL NATURALN NEW NEXTVAL NOAUDIT NOCOMPRESS NOLOGGING NOT NOWAIT NULL NUMBER NUMBER_BASEOF OFFLINE ON ONLINE OPEN OPTION OR ORDER OTHERS OUTPACKAGE PARTITION PCTFREE PCTUSED PLS_INTEGER POSITIVE POSITIVEN PRAGMA PRIOR PRIVATE PRIVILEGES PROCEDURE PUBLICRAISE RANGE RAW REAL RECORD REF RELEASE REMR RENAME RESOURCE RETURN REVERSE REVOKE ROLLBACK ROW ROWID ROWLABEL ROWNUM ROWS ROWTYPE RUN SAVEPOINT SCHEMA SELECT SEPARATE SESSION SET SHARE SMALLINT SPACE SQL SQLCODE SQLERRM START STATEMENT STDDEV SUBTYPE SUCCESSFUL SUM SYNONYM SYSDATETABAUTH TABLE TABLES TASK TERMINATE THEN TO TRIGGER TRUE TYPEUID UNION UNIQUE UPDATE USE USERVALIDATE VALUES VARCHAR VARCHAR2 VARIANCE VIEW VIEWSWHEN WHENEVER WHERE WHILE WITH WORK WRITEXOR/C2 'Packages'DBMS_OUTPUTDBMS_JOBDBMS_SQL/C3 'Package Methods'BIND_VARIABLE BIND_VARIABLE_CHAR BIND_VARIABLE_RAW BIND_VARIABLE_ROWID BROKENCHANGE CLOSE_CURSOR COLUMN_VALUE COLUMN_VALUE_CHAR COLUMN_VALUE_RAW COLUMN_VALUE_ROWIDDEFINE_COLUMN DEFINE_COLUMN_CHAR DEFINE_COLUMN_RAW DEFINE_COLUMN_ROWID DISABLEENABLE EXECUTE EXECUTE_AND_FETCHFETCH_ROWSGET_LINE GET_LINESINTERVAL IS_OPENLAST_ERROR_POSITION LAST_ROW_COUNT LAST_ROW_ID LAST_SQL_FUNCTION_CODENEW_LINE NEXT_DATEOPEN_CURSORPARSE PUT PUT_LINEREMOVESUBMITWHAT/C4 'SQL*Plus Commands'EXECUTEGRANTREPLACERUNSTART/C5 'SQL*Plus Functions'ABS ADD_MONTHS ASCIICEIL CHR CONCAT CONVERT COS COSHDECODEEXPFLOORGREATESTHEXTORAWINITCAP INSTRLAST_DAY LENGTH LN LOG LOWER LPAD LTRIMMOD MONTHS_BETWEENNEXT_DAY NEW_TIME NLS_INITCAP NLS_LOWER NLS_UPPER NVLPOWERRAWTOHEX REPLACE ROUND ROWIDTOCHAR RPAD RTRIMSIGN SIN SINH SOUNDEX SQRT SUBSTR SUBSTRBTAN TANH TO_CHAR TO_DATE TO_LABEL TO_MULTI_BYTE TO_NUMBER TO_SINGLE_TYPE TRANSLATE TRUNCUPPER USERENVVSIZE/C6 'Should Be Reserved'BEFOREEACHFORKEYPRIMARYWHEN WHERE WHILE/C7 'CONST Var'DUP_VAL_INDEX TIMEOUT_ON_RESOURCE TRANSACTION_BACKED_OUT INVALID_CURSOR NOT_LOGED_ON LOGIN_DENIEDNO_DATA_FOUND SYS_INVALID_ROWID TOO_MANY_ROWS ZERO_DIVIDE INVALID_NUMBER STORAGE_ERROR PROGRAM_ERROR VALUE_ERRORNOTFOUND FOUND