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 […]

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 […]

How to Resolve ORA-00904 Invalid Identifier

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Oracle Database Object Name Recognition Examples
Database Object Naming Rules Normally, Oracle treats most identifiers as case insensitive ones excepts password. But there’s some special usages should be taken care of in case of ORA-00904 invalid identifier generated. Not only ORA-00904, but ORA-00903 and ORA-00911 are also related to invalid usage on object identifiers. More specifically, ORA-00903 alerts users for invalid […]
Installation and Upgrade

How to Install Oracle Software in Silent Mode

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With a Response File First of all, we have prepared a response file for installing Oracle software only as following. Let’s see the effective content of the response file. [oracle@ora11g ~]$ egrep -v “(^(#|$)|=$)” install-software-only-for-11g.rsp oracle.install.responseFileVersion=/oracle/install/rspfmt_dbinstall_response_schema_v11_2_0 oracle.install.option=INSTALL_DB_SWONLY ORACLE_HOSTNAME=ora11g UNIX_GROUP_NAME=oinstall INVENTORY_LOCATION=/u01/app/oraInventory SELECTED_LANGUAGES=en,zh_TW ORACLE_HOME=/u01/app/oracle/product/11.2.0/dbhome_1 ORACLE_BASE=/u01/app/oracle oracle.install.db.InstallEdition=EE oracle.install.db.EEOptionsSelection=false oracle.install.db.DBA_GROUP=dba oracle.install.db.isRACOneInstall=false oracle.install.db.config.starterdb.type=GENERAL_PURPOSE oracle.install.db.config.starterdb.memoryOption=false oracle.install.db.config.starterdb.installExampleSchemas=false oracle.install.db.config.starterdb.enableSecuritySettings=true oracle.install.db.config.starterdb.control=DB_CONTROL oracle.install.db.config.starterdb.automatedBackup.enable=false SECURITY_UPDATES_VIA_MYORACLESUPPORT=false DECLINE_SECURITY_UPDATES=true […]

How to Stop XMLRPC Attack in WordPress

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XML-RPC Attack
Saw a HTTP attack, it sent 12 to 20 requests per second on /xmlrpc.php, then made web server jam. In HTTP access log, we saw a lot of requests like this: – – [03/Mar/2019:21:35:40 -0500] “POST /xmlrpc.php HTTP/1.1” 200 401 – – [03/Mar/2019:21:35:40 -0500] “POST /xmlrpc.php HTTP/1.1” 200 401 – – [03/Mar/2019:21:35:40 […]
Oracle Client

Difference between Oracle Client and Oracle Instant Client

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Here I list their differences including features, pros and cons for you to evaluate which one should be used for your clients: Oracle Client Features Install-based software All-in-one functions General-purpose package Oracle database enterprise edition download page Oracle clients stay with Oracle database software, so there’s no dedicated download page for Oracle clients. Pros One-stop […]

4 Types of SQL in Relational Database

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Types of SQL Statements SQL statements in relational database management system (RDBMS) could sometimes be too complicated to be analyzed for. As SQL developers, we should at least be able to distinguish what types of the statements that are using. According to conventional SQL classification, there are 4 basic types of SQL statements. Data Query […]

How to Change SPFILE Location

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Change SPFILE Location Generally, we don’t change SPFILE location, because it should be found in the default location, $ORACLE_HOME/dbs/spfile$ORACLE_SID.ora any time to startup the instance without any explicit indication. SQL> startup Which means, the database will find appropriate SPFILE or PFILE in the default location to startup the instance. Of course, anything is not impossible […]
Control File

How to Change Control File Location

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Change Control File Location Here are the steps to change the location of control file: Stop Database Service Copy Control File to New Location Create PFILE from Current SPFILE Modify Control File Location in PFILE Restore SPFILE from Modified PFILE Startup NOMOUNT to Check New Setting Open Database If you’d like to move SPFILE as […]