Oracle Database

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Introduction Oracle Database 10g Release 1 introduced Automatic Storage Management (ASM), a new framework for managing Oracle database files. ASM provides a foundation for highly efficient storage management with direct I/O, redundancy, striping and load balancing. Files stored on ASM are evenly distributed across disks in a disk group and mirrored according to the policies defined in the disk group…. Continue Reading →

10g, 11g, 12c, All Things Oracle Full Articles

Rebuilding indexes is an activity that you shouldn’t need to do often. There are always a few special cases – like when you’ve moved or recreated a table or if you’ve done a massive delete on a table – when it’s probably a reasonable idea but, in general, there are very few cases where there’s any great benefit to be… Continue Reading →

All Things Oracle Full Articles, Oracle Database, Troubleshooting

The Oracle Database In-Memory option was introduced in Oracle 12c (12.1.0.2 patch set). By using the In-Memory option, businesses can benefit from better decisions made in real time, improved productivity, increased competitiveness and lowered costs. The Oracle In-Memory option is designed to fit both Data warehouse and mixed workload OLTP databases, and can be deployed with any existing application that… Continue Reading →

12c, All Things Oracle Full Articles

Cloning of a Pluggable Database (PDB) in Oracle Multitenant is a great feature and is very useful. Oracle Database 12c Release 1 has introduced various enhancements to the cloning of Pluggable Databases to overcome the limitations imposed by the initial release of Oracle Database 12c (12.1.0.1). In Oracle 12.1.0.2c: PDBs can be hot cloned, i.e. you don’t need to put the source PDB… Continue Reading →

12c, All Things Oracle Full Articles

In the initial release of Oracle 12c (12.1.0.1c), a non-Container Database (non-CDB) could be converted to a pluggable database (PDB) using any of the following methods: Using DBMS_PDB Using datapump (expdb, impdp) Using GoldenGate replication The 12.1.0.2 patchset has introduced the ability to clone a remote non-CDB as a PDB directly over the network. Remote Cloning of a Non-CDB is a… Continue Reading →

12c, All Things Oracle Full Articles

In the previous installment of this series I produced some figures highlighting the main differences between doing a large delete by tablescan and doing a large delete by index range scan. Depending on the data patterns involved the correct choice of strategy could make a significant difference to the number of random I/Os, the volume of redo generated, and the… Continue Reading →

12c, All Things Oracle Full Articles

Oracle 12c has introduced Flex Clusters which use hub-and-spoke technology, allowing the cluster to scale much beyond the pre-12c clusters as it requires: Fewer network interactions between nodes in the cluster, and : Less contention for key Clusterware resources like OCR and voting disks. A Flex Cluster has two types of nodes: Hub Nodes and Leaf Nodes. Hub Nodes These… Continue Reading →

12c, All Things Oracle Full Articles

In an earlier article, I discussed Automatic big table cache (ABTC) which is a new feature introduced in Oracle Database 12.1.0.2c. Automatic big table cache is an optional section of the buffer cache reserved for storing large objects. It tracks only big tables and automatically caches scanned big objects in big table cache thereby avoiding direct path reads. It caches… Continue Reading →

12c, All Things Oracle Full Articles

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

In Part 1 of this short series I provided an informal description of a couple of scenarios where we might do a large-scale delete from a table. Without a concrete example though, it can be hard to imagine how the nature of the data deleted and the access paths available could affect the impact a large delete operation could have… Continue Reading →

12c, All Things Oracle Full Articles