Alert Log File

Where is Oracle Alert Log Location

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The Default Location of Oracle Alert Log The location of Oracle alert log may not be easily found, but it’s usually at 3 possible locations: For 11g and Above $ORACLE_BASE/diag/rdbms/<dbname_in_lower_case>/$ORACLE_SID/trace/ As we can notice, Oracle software divides alert logs to their own dedicated directories according to their database names, which is based on directory structure […]
Listener Log

Where is Oracle Listener Log Location

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The Default Location of Oracle Listener Log If you have read Where to Find Oracle Alert Log Location, you may have some clues to find the right listener.log. But there’re some differences between them. For 11g and above The default location of listener log for 11g or above can be found at: [oracle@ora11g ~]$ ll […]
RMAN

How to Resolve ORA-19602: cannot backup or copy active file in NOARCHIVELOG mode

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Found ORA-19602 When I tried to backup a NOARCHIVELOG database in MOUNT state, I got ORA-19602 like the following case: RMAN> startup mount; … RMAN> backup database tag ‘20190416-before-yearly-import’; Starting backup at 16-APR-19 using target database control file instead of recovery catalog allocated channel: ORA_DISK_1 channel ORA_DISK_1: SID=393 device type=DISK channel ORA_DISK_1: starting full datafile […]
Database Link

What DB Link Can and Cannot Do

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Can and Cannot For better understanding the features of a database link which may play an important role in data migration, we should study what a database link can and cannot do in a distributed database system in order to develop our data migration strategy. Generally speaking, you can perform Data Query Language (DQL) and […]
SQL

How to Resolve ORA-00903: invalid table name

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In this post, I will introduce 3 main error patterns about ORA-00903, they are: Violating Naming Rules Missing Quotes Incorrect Syntax ORA-00903 due to Violating Naming Rules Without complying with database object naming rules, we can’t create a table with unusual strings in normal way. Let’s see some cases that throw ORA-00903. First of all, […]
Data Guard

How to Resolve ORA-01579 in MRP

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ORA-01579 in MRP After shrinking (i.e. resizing) a data file successfully, I was worry about the applying state of the standby database. Not surprisingly, I found ORA-01579: write error occurred during recovery in Managed Recovery Process (MRP) log. oracle@boston>tail -f orcl_mrp0_23309410.trc … *** 2019-03-15 08:51:13.521 Media Recovery Log /oradata/ORCL/ARCH/ORCL_1_342376.arc *** 2019-03-15 09:02:01.230 Media Recovery Log […]
WebLogic

How to Resolve WebLogic Startup Slow

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WebLogic Startup Slow After long WebLogic installation, I found that every time I startup WebLogic Server, it took about 10 to 15 minutes to complete. Which is unbearable and unacceptable for a production environment. Rationale This is because JVM library used for random number generation relies on /dev/random by default for UNIX platforms. This can […]
SQL

如何解決ORA-00904 無效的 ID

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ORA-00904 通常,Oracle會將大多數識別名視為不區分大小寫的識別名,但不包括密碼。但是在ORA-00904生成無效識別名的情況下應該注意一些特殊用法。 不僅ORA-00904,ORA-00903和ORA-00911也與物件識別名的無效使用有關。更具體地說,ORA-00903警告用戶無效的表格名稱,ORA-00911則是非法字元的使用。 根據Oracle資料庫物件名稱和限定符,有兩種有效的命名形式來建立資料庫物件。一個是非引用識別名,另一個是帶引號的識別名。 稍後,我們還將討論有關ORA-00904無效識別名的更多問題。 每個部分的摘要 以下是我們將在本文中討論的每個部​​分的摘要。 無引號識別名(鬆散形式) 它們沒有標點符號或任何其他特殊處理。只要它們基本上是等效的字元串,我們就可以在SQL語句中不區分大小地靈活使用它們。所以我通常在這篇文章中將其稱為鬆散形式 本節中的錯誤模式包括: 由於不存在的欄位而導致的ORA-00904 由於不存在的函數而導致的ORA-00904 由於拼寫錯誤的欄位而導致的ORA-00904 帶引號的識別名(精確形式) 它們以雙引號(””)開頭和結尾。您可以將幾乎所有字元放在雙引號中,包括空格和保留字。這種識別名的使用應該與最初定義的完全一致。所以我通常在這篇文章中將其稱為精確形式。 本節中的錯誤模式包括: 由於缺少雙引號而導致的ORA-00904 欄位名稱中的空白 其他命名規則 不僅有引號形式,還有無引號形式,有幾個與ORA-00904相關的重要命名規則,如保留字,有效特殊字元和識別名長度,我們也應該注意。 本節中的錯誤模式包括: 由於使用保留字而導致的ORA-00904 由於以數字開頭而導致的ORA-00904 由於濫用特殊字元而導致的ORA-00911 由於識別名超過30字節而導致的ORA-00972 由於錯誤添加了額外的逗號而導致的ORA-00904 拼寫錯誤的欄位名稱是上面討論過的錯誤模式,你必須更正識別名以使你的語句有效。在本節中,我們將討論ORA-00904的一個非常奇怪的錯誤模式,這是在CREATE TABLE中錯誤添加的額外逗號。 由於PL/SQL中的變數宣告順序不正確而導致的ORA-00904 編程單元允許我們宣告變數,控制流程並輸出結果。調試編程單元有時是一項漫長而乏味的工作。在本節中,您可以在PL/SQL代碼塊中看到ORA-00904的錯誤模式,該錯誤模式與變數宣告的順序有關。 我們來看一下欄位名稱上ORA-00904的一些錯誤類型。在大多數情況下,濫用欄位名稱是ORA-00904的主要來源。 採用鬆散形式所發生的ORA-00904 通常,我們會建立一個表格而不使用雙引號: SQL> create table all_names_1 (First_Name varchar2(25), Last_Name varchar2(25)); Table created. 然後我們插入一些數據。 SQL> insert into all_names_1 select distinct first_name, last_name from employees; 107 […]