Quality of Service Management In previous Oracle Database releases, you could use services for workload management and isolation. For example, a group of servers might be dedicated to data warehouse work, while another is dedicated to your sales application, a third group is used for ERP processing, and a fourth group to a custom application. Using services, the database administrator can allocate resources to specific workloads by manually changing the number of servers on which a database … [Read more...] about Understanding Oracle Database Quality of Service (QoS) Management
Beginners Guide to Oracle Database In-Memory in RAC
In-Memory Column Store In-Memory (IM) column store is a new pool in SGA introduced in Oracle Database Release 12.1, Patchset 1. Segments populated into the IM column store are converted into a columnar format. In-Memory segments are transactionally consistent with the buffer cache. The In-Memory Column Store enables objects (tables, partitions, and other types) to be stored in memory in a new format known as the columnar format. This format enables scans, joins, and aggregates to perform … [Read more...] about Beginners Guide to Oracle Database In-Memory in RAC
How to Convert RAC One Node Database to RAC (and Oracle RAC One Node to RAC database)
Oracle RAC One Node Oracle RAC One Node is a single instance of an Oracle RAC-enabled database running on one node in the cluster, only, under normal operations. This option adds to the flexibility that Oracle offers for database consolidation while reducing management overhead by providing a standard deployment for Oracle databases in the enterprise. Oracle RAC One Node database requires Oracle Grid Infrastructure and, therefore, requires the same hardware setup as an Oracle RAC … [Read more...] about How to Convert RAC One Node Database to RAC (and Oracle RAC One Node to RAC database)
Oracle Database 12c New Feature: Transaction Guard and Application Continuity
Introducing Transaction Guard and Application Continuity Oracle Database 12c introduces two fundamental capabilities for ensuring continuity of applications after database outages: A foolproof way for applications to know the outcome of transactions The ability to mask outages by reconnecting to the database and replaying the workload These capabilities are provided by two new features: Transaction Guard and Application Continuity. Transaction Guard is an API that applications use … [Read more...] about Oracle Database 12c New Feature: Transaction Guard and Application Continuity
Types of Workload Distribution (Load Balancing) in Oracle RAC
Types of Workload Distribution With RAC, multiple listeners on multiple nodes can be configured to handle client connection requests for the same database service. A multiple-listener configuration enables you to leverage the following failover and load-balancing features: Client-side connect-time load balancing Client-side connect-time failover Server-side connect-time load balancing These features can be implemented either one by one, or in combination with each other. Moreover, if … [Read more...] about Types of Workload Distribution (Load Balancing) in Oracle RAC
Understanding the Global Resource Management Concepts in Oracle RAC
Need for Global Concurrency Control Latches and mutexes may only protect access to memory structures if they are accessed by processes in the same instance. In RAC, latches and mutexes are still used, but for global concurrency control, some additional global enqueues are used to provide protection across instances. Oracle requires concurrency control because it is a multi-user system. Single-instance Oracle provides concurrency control: Latches or mutexes for memory structures Enqueues for … [Read more...] about Understanding the Global Resource Management Concepts in Oracle RAC
RMAN backup Concepts for Oracle RAC
Oracle Recovery Manager Oracle Database provides RMAN for backing up and restoring the database. RMAN enables you to back up, restore, and recover data files, control files, SPFILEs, and archived redo logs. You can run RMAN from the command line or you can use it from the Backup Manager in Enterprise Manager. In addition, RMAN is the recommended backup and recovery tool if you are using ASM. RMAN can use stored scripts, interactive scripts, or an interactive GUI front end. When using RMAN with … [Read more...] about RMAN backup Concepts for Oracle RAC
Archived Redo File Conventions in Oracle RAC
Archived Redo File Conventions in RAC Variable Description Example %tThread number, not paddedlog_1 %TThread number, left-zero-paddedlog_0001 %sLog sequence number, not paddedlog_251 %S Log sequence number, left-zero-padded log_0000000251 %rResetlogs identifierlog_23452345 %RPadded resetlogs identifierlog_0023452345 %t_%s_%r Using multiple variables log_1_251_23452345 For any archived redo log configuration, uniquely identify the archived redo logs with the … [Read more...] about Archived Redo File Conventions in Oracle RAC
Understanding Transparent Data Encryption and Keystores in RAC
Transparent Data Encryption and Keystores in RAC Oracle Database enables RAC nodes to share the keystore (wallet). This eliminates the need to manually copy and synchronize the keystore across all nodes. Oracle recommends that you create the keystore on a shared file system. This allows all instances to access the same shared keystore. Oracle RAC uses keystores in the following ways: Any keystore operation, such as opening or closing the keystore, performed on any one Oracle RAC … [Read more...] about Understanding Transparent Data Encryption and Keystores in RAC
How to Termibate a Session on a Specific Instance of Oracle RAC
Terminating Sessions on a Specific Instance You can use the ALTER SYSTEM KILL SESSION statement to terminate a session on a specific instance. The example below illustrates this by terminating a session started on a different instance than the one used to terminate the problematic session. SQL> SELECT SID, SERIAL#, INST_ID 2 FROM GV$SESSION WHERE USERNAME='JMW'; SID SERIAL# INST_ID ---------- ---------- ---------- 140 3340 2 SQL> ALTER SYSTEM KILL SESSION … [Read more...] about How to Termibate a Session on a Specific Instance of Oracle RAC