DBORCLOUD Blog

ORACLE 12C M.T.S. model

Until Oracle Database 12c, Oracle processes did not run as threads on UNIX and Linux systems. Every dedicated connection was represented by an operating system process. In systems where high workload was an issue, the only way to reduce CPU and memory usage was to switch from dedicated connections to shared connections using the multithreaded server (MTS) feature. Starting in Oracle Database 12c the multithreaded database model was introduced, enabling database processes to be executed as operating system threads and reducing the number of dedicated process necessary to manage database services. By default, every new 12c instance is created to Read More

MODIFICA SQLPROMPT CONTAINER E PLUGGABLE DATABASE

Per impostare il nome dell’istanza sul prompt della macchina e contestualmente il nome utente e il nome dell’istanza in sqlplus eseguiamo con le seguenti modifiche: ENV PDB – Modificare l’export dell’istanza nell’env del PDB inserendo il nome del pluggable database export ISTANZA=RELAUP – Cambiare nell’export della variabile PS1 ORACLE_SID con ISTANZA export PS1='\u@${HOSTNAME}:${ISTANZA} # ' – Inserire l’export della variabile SQLPATH export SQLPATH=/home/oracle12/cfg ENV CDB – Inserire l’unset del SQLPATH, perchè se rimene settata ci si connette al PDB perché esegue il file login.sql all’interno della directory SQLPATH unset SQLPATH Di seguito gli env di GRELAUP e RELAUP: oracle12@lradbpvm01:RELAUP # Read More

2 PHASE COMMIT OVERVIEW

Two-phase commit protocol is comprised of a set of actions that ensure a transaction involving multiple databases does not produce unsynchronized updates. Two-phase commit provides a way for a series of database interactions on multiple different data sources to be grouped together and completed or rolled back as a single transaction. Two-phase commit transactions that represent a series of database interactions on multiple data sources are referred to as global transactions. At the beginning of a global transaction, a global transaction ID (XID) is generated and used by an external transaction manager to drive the two-phase commit processing across all Read More

2 PHASE COMMIT OVERVIEW

Two-phase commit protocol is comprised of a set of actions that ensure a transaction involving multiple databases does not produce unsynchronized updates. Two-phase commit provides a way for a series of database interactions on multiple different data sources to be grouped together and completed or rolled back as a single transaction. Two-phase commit transactions that represent a series of database interactions on multiple data sources are referred to as global transactions. At the beginning of a global transaction, a global transaction ID (XID) is generated and used by an external transaction manager to drive the two-phase commit processing across all Read More