Anju Garg

Author

Serial direct path reads were first introduced in Oracle 11g to prevent wiping out a large number of buffers from the buffer cache by a serial large table scan. As a result, big tables accessed via serial Full Table Scans bypass the Buffer Cache and read data from the Data Files into the users’ Program Global Area (PGA). This prevents flooding… Continue Reading →

12c, All Things Oracle Full Articles

Prior to Oracle Database 12c, an ASM instance ran on every node in the cluster and ASM Cluster File System (ACFS) Service on a node connected to the local ASM instance running on the same host to fetch the required metadata. If the ASM instance on a node were to fail, then ACFS file systems could no longer be accessed… Continue Reading →

12c, All Things Oracle Full Articles

In an Oracle cluster prior to version 12.1.0.2c, when a split brain problem occurs, the node with lowest node number survives. However, starting from Oracle Database 12.1.0.2c, the node with higher weight will survive during split brain resolution. In this article I will explore this new feature for one of the possible factors contributing to the node weight, i.e. the… Continue Reading →

12c

Oracle Data Pump was introduced in Oracle Database 10g to enable very high-speed transfer of data and metadata between databases. A salient feature of Data Pump is that it can parallelize the export and import jobs for maximum performance. However, prior to Oracle Database 11g release 2 (11.2), if a Data Pump job is executed in parallel on an instance… Continue Reading →

11g, 12c, All Things Oracle Full Articles

In Oracle Database Releases earlier than 12c, an Automatic Storage Management (ASM) instance runs on every node in the cluster, and ASM Cluster File System (ACFS) Service on a node connects to the local ASM instance running on the same host. If the ASM instance on a node were to fail, then the shared Disk Groups and hence ACFS file… Continue Reading →

12c, All Things Oracle Full Articles

Starting with Oracle Grid Infrastructure 12c (12.1), Oracle Cloud File system (ASM Cluster File System in cluster environment) supports database files (database version 11.2.0.4 and up) in addition to general-purpose files so that entire Oracle databases can be stored inside Oracle Cloud FS. In my earlier articles I demonstrated that: For a database having its files stored on Oracle Cloud… Continue Reading →

All Things Oracle Full Articles, Backup and Recovery

In my last article, I demonstrated that starting with Oracle Grid Infrastructure 12c (12.1), Oracle Cloud File system (ASM Cluster File System in cluster environment) supports database files (database version 11.2.0.4 and up) in addition to general purpose files, so that entire Oracle databases can be stored inside Oracle Cloud FS. In addition, for a database with its files stored… Continue Reading →

All Things Oracle Full Articles, Backup and Recovery

Starting with Oracle Grid Infrastructure 12c (12.1), Oracle Cloud File system (ASM Cluster File System in cluster environment ) supports database files (database version 11.2.0.4 and up) in addition to general purpose files so that entire Oracle databases can be stored inside Oracle Cloud FS and can leverage the Advanced Data Services such as snapshots, tagging and auditing although replication and… Continue Reading →

12c, All Things Oracle Full Articles

Prior to Oracle Grid Infrastructure (GI) release 12.1.0.2, ASM Library (ASMLIB) was the only method to access storage devices by means of ASM Disks and Diskgroups. There were serious limitations to this method. The ASM disks were owned by GI home owner and both the owner and any users belonging to an operating system group designated as the OSASM group… Continue Reading →

All Things Oracle Full Articles, Database Administration, Database Development

Prior to oracle database 12c, the procedures for converting from single-instance databases to Real Application Clusters involved following steps: Configure the control file attributes and move control file to shared storage Make the initialization parameter file entries for cluster-enabled environments and move SPfile to shared storage Create an undo tablespace for each additional instance Create redo threads for each additional… Continue Reading →

12c, All Things Oracle Full Articles, Database Administration, Database Development, RAC