TimesTen JDBC Connection Pool Using UCP (Universal Connection Pool)
JDBC Connection to TimesTen in-memory database could be obtained either through the TimesTenDataSource or loading one of the TimesTen drivers (TimesTenDriver or TimesTenClientDriver) using...
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Session Cached Cursors and JDBC PreparedStatement
Given two pseudo codes which would be better in terms of performance?table.myTable { border-collapse:collapse; } table.myTable td, table.myTable th { border:1px solid black;padding:5px; } Case 1VsCase...
View ArticleOracle Invoked Out-of-Memory Killer (oom-killer)
One node on a 2-node RAC (11.1.0.7) crashed and following could seen on the /var/log/messagesFeb 11 09:46:01 server02 logger: Oracle CSSD waiting for OPROCD to startFeb 11 22:46:21 server02 kernel:...
View ArticleChecking If Server Is Physical Or Virtual
There are several ways to check if the server is a physical server or virtual server. Post list just two such methods.1. Using dmidecodeAmong many information listed by the dmidecode command (requires...
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Session Cached Cursors and JDBC CallableStatement
Similar to earlier post that compared the various preparedstatments scenarios this post examine the use of callablestatements and the effects of session cached cursors (SCC) parameter. Case 1 and Case...
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Oracle vs Standard JDBC Batching For Updates
Oracle provided two flavors of batching with the JDBC drivers. One was called standard which followed the JBDC 2.0 specification and the other flavor was an Oracle specific implementation (called...
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Deleting a Node From 12cR1 RAC
Deleting a node from a 12cR1 RAC is similar to that of 11gR2. Deletion has three distinct phases, that is removing of the database instance, removing of Oracle database software and finally the...
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Adding a Node to 12cR1 RAC
This post list the steps for adding a node to 12cR1 standard cluster (not to a flex cluster) which is similar to that of adding a node to 11gR2 RAC. Node addition is done in three phases. Phase one is...
View ArticleORA-20006: Number of RAC active instances and opatch jobs configured are not...
Following error could be observed when running the "Loading Modified SQL Files into the Database" section under the "Patch Post-Installation Instructions" during a PSU apply. In this case the system...
View ArticleSkipping Tablespace During Backup and Recovery
Oracle provides skip and exclude options to keep a tablespace(s) out of a full database backup. However when the restore happens this exclusion must be handled before the database could be used by the...
View ArticleORA-30012: undo tablespace does not exist or of wrong type
The following error message was observed on the alert logs of all but one instance trying to start them after a switchover using dataguard broker.Undo initialization errored: err:30012 serial:0...
View ArticleRecreating Dataguard Broker Configuration After ORA-16816: Incorrect Database...
Following a failed switchover using dataguard broker the database role information was in a inconsistent state.DGMGRL> show configurationConfiguration - APDG Protection Mode: MaxPerformance...
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GNS Setup for RAC
Setting up a GNS is not a must to install a RAC unless it's a flex cluster where the use of a GNS is mandatory. There are some advantages to using GNS, especially when it comes to adding and removing...
View ArticleCreating Extended Statistics With Function-base Column Groups
There are nine restrictions to creating extended statistics. These restrictions are same for version 11.1, 11.2 and 12.1.. One of the constraints is "A column group can not contain expressions". Oracle...
View ArticleASM Disk Group Dependency Exists Even After Being Dropped
Database using ASM has storage has dependency on the ASM disk groups.[oracle@rhel6m1 ~]$ srvctl config database -d std11g2Database unique name: std11g2Database name: std11g2Oracle home:...
View ArticleRMAN-05609: Must specify a username for target connection when using active...
In 11gR2 it was possible to run an active duplication command for data guard and cloning of DB via duplication without explicitly specifying a username for the target instance.But in 12c1 this would...
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Upgrade Oracle Database 12c1 from 12.1.0.1 to 12.1.0.2
This post list the steps of upgrading from 12.1.0.1 to 12.1.0.2 for single instance database in a data guard configuration (physical standby). The single instance databases are non-CDB. When upgrading...
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enq: HW - contention and latch: enqueue hash chains
An application uses serialized java objects to stored in the database to overcome the application server failovers. The java objects are stored as BLOB. Application has been using the same session...
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Nologging vs Logging for LOBs and enq: CF - contention
Changing the logging option is one of the possible performance tuning tasks when dealing with LOBs. However use of nologging will make recovery of these lob segments impossible as such use of this will...
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LOB Chunk and Tablespace Block Size
Chunk value corresponds to the data size used by oracle when reading or writing a lob value. Once set chunk size cannot be changed. Though it doesn't matter for lobs stored in row, for out of row lobs...
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