SQLPlus Connect and Disconnect
SQLPlus Connect To connect a database, we usually use sqlplus, a text-based connection tool provided by Oracle to facilitate clients to connect to a running… Read More »SQLPlus Connect and Disconnect
Connect Descriptor
TNSNAMES, How and Why
Local Naming = TNSNAMES Whenever we need to connect to the database, we usually provide a connection string like this: SQL> conn username/password@chicago-db-server:1521/ORCL Connected. Or… Read More »TNSNAMES, How and Why
How to Resolve ORA-12528: TNS:listener: all appropriate instances are blocking new connections
ORA-12528 Tried to connect a NOMOUNT database, but it failed with ORA-12528. C:\Users\ed>sqlplus sys/password@orcl as sysdba ... ERROR: ORA-12528: TNS:listener: all appropriate instances are blocking… Read More »How to Resolve ORA-12528: TNS:listener: all appropriate instances are blocking new connections
How to Resolve ORA-12154: TNS:could not resolve the connect identifier specified
ORA-12154 ORA-12154 means that your connection tools (e.g. sqlplus) cannot use TNSNAMES naming method for some reason. This reminds me that there're same error patterns… Read More »How to Resolve ORA-12154: TNS:could not resolve the connect identifier specified
SQLPlus Connect without Tnsnames
SQLPlus without Tnsnames We usually connect a database by sqlplus through tnsnames.ora, but sometimes we are not allowable to change or access tnsnames.ora, even worse,… Read More »SQLPlus Connect without Tnsnames
How to Resolve ORA-12514: TNS:listener does not currently know of service requested in connect
ORA-12514 ORA-12514 means that the listener cannot find any matched service with yours, so it cannot establish the connection with the database for you. As… Read More »How to Resolve ORA-12514: TNS:listener does not currently know of service requested in connect
How to Resolve TNS-03505: Failed to resolve name
TNS-03505 Failing to resolve TNS names could involve any one of the network configuration files, such as tnsnames.ora or sqlnet.ora. There're several possible causes may… Read More »How to Resolve TNS-03505: Failed to resolve name