The appearance of ORA-12557 sometimes works with ORACLE

ORA-12557: TNS: protocoladapternotloadableCause: Onsomeplatforms (suchasOS2) protocoladaptersareloadedatrun-time.Ifthesharedlibrary (orDLL) fortheprotocoladapterismissingoroneofitssupportinglibrariesismissingth

ORA-12557: TNS: protocol adapter not loadable Cause: On some platforms (such as OS/2) protocol adapters are loadedat run-time. if the shared library (or DLL) for the protocoladapter is missing or one of its supporting libraries is missingth

ORA-12557:	TNS: protocol adapter not loadable
Cause:	On some platforms (such as OS/2) protocol adapters are loadedat run-time. if the shared library (or DLL) for the protocoladapter is missing or one of its supporting libraries is missingthen this error is returned.
Action:	For further details, turn on tracing and reexecute theoperation. The trace file will include the name of the sharedlibrary (or DLL) that cocould not be loaded.

1. Make sure% ORACLE_HOME %/binDirectory (that is, the directory) is in your (environment variable) PATH. // the appearance of the ORA-12557 is sometimes related to ORACLE_HOME not set or setup Error
2. Make sure the protocol is typed/specified correctly in your
Tnsnames. oraFile or whatever source you're using to resolve service
Names.
3. TCP is the default protocol and is installed by default. If
You're using something different (like SPX) make sure you installedthe
Protocol adapter.
4. Make sure TOAD is usingCorrect oracle_homeIf youhave
Multiple homes installed

------------------------- Two instances are installed in the environment, one 9i and the other 10 Gb.

SQL> conn sys/admin @ c11 assysdba;
ERROR:
ORA-12557: TNS: protocol adapter not loadable

------ Lsnrctl> status Error

Message 1053 not found; No message file for product = NETWORK, facility = TNSTNS-12538: Message

12538 not found; No message file for product = NETWORK, facility = TNS
TNS-12560: Message 12560 not found; No message file forproduct = NETWORK, facility = TNS
TNS-00508: Message 508 not found; No message file forproduct = NETWORK, facility = TNS

---------------

1. reconfigure the listener

2. Run echo % oracle_home % to check whether the opened instance is in this directory.

If set oracle_home = d: oracleora92 is not set

From: http://steve352.itpub.net/post/33251/306560

Today, a friend installed 9I and 10.ORA-12557, Oracle_sid modification error still,After oracle_home is changed to oracle_home of the current database, the problem is solved.

Note:

1. ORACLE_HOME is the root directory of the software installed in Oracle. Based on this root directory, Oracle can locate other related programs

(If ORACLE_HOME is incorrect, for example, an error occurs when you cannot find the relevant program when you start the database or log on to ORACLE_HOME)

2. SID is the identifier of the database when a database is created.

3. If there are two or more instances in a version, how can I set oracle_sid?

In fact, the oracle_sid setting in the environment variable is only the database connected by default when the conn does not contain @. Therefore, there is only one database, which can be left unspecified. However, if there are two or more instances in a version, the conn must contain @ sid_name.(Sid_name is a network service name. Note that you must enable the listener for lsnrdbms start)

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ORA-12557: TNS: protocol adapter not loadable

Environment background: the local machine has multiple oracle instances (11, 9i), and the oracle of the Connected Server is 9i

Cause: I just entered the company, so my computer domain account is still not approved. I used my previous account to log on to the system. Everything is normal.
Consequence: my account is down, so I log on to my computer with my own account and reset all the configurations. At this time, all the environment variables are reset. When all the environment variables are set the same as before, I thought it was done.

Open plsql, connection oralce, reported this error: ORA-12557, online to find a lot, are not the cause of my problem, engaged in an afternoon, it is really wrong, look for the company to see, the great God went straight to the topic, click Open in plsql, help-> support information, see the OCI 11g in the Preferences oci Library. dll.

Open the two Default. ini Files in Preference Files and change OCIFile to the 9i path (OCIFile = D: \ Oracle9i \ ora90 \ BIN \ oci. dll.


Khan ~~~~~~~~~~ It took me less than a minute to get started.