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Oluwatobi Ogunsola
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LOAD_BALANCE OFF Still checks other ADDRESS list. DB Connection consideration.
This note highlight performance penalty that can comes with using database connection with multiple address, contradicting what oracle document says, at least at "surface level". this is worth considering when setting up application connection in DR/datagua...
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Fixed for Materialized View slow refresh or hangs (1)
Fixed for  Materialized View slow refresh or hangs.    I did a performance tuning on a database where the application developer, literally are solving all performance problems with materialized views!?. redo log switch occurs 300 times within an hour becaus...
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MANUALLY CREATE HISTOGRAM WITHOUT WORKLOAD OR COLUMN USAGE INFORMATION IN SYS.COL_USAGE$
MANUALLY CREATE HISTOGRAM WITHOUT WORKLOAD OR COLUMN USAGE INFORMATION IN SYS.COL_USAGE$ For skew data, histogram provides better statistics based on data distribution to help optimizer "to generate accurate cardinality estimates for filter and join predica...
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Oracle IO, Storage and CPU Limits: Knowing Your Environment Limits.
I did some test related Oracle IO, Storage I/O and CPU limits. In a bit to understands an environment limits, potential bottlenecks and performance characteristics and capacity, I did some test related to Oracle IO, Storage I/O and CPU limits. Enjoy and lea...
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Linux Resource Control and allocation cgroups with dd process example. users having different resource cap.
Imagine a client want dd process to be limited. Any OS user
that runs dd except root user should be limited to read of 2MiB/s. IO rate is specified
in bytes per second. root can run dd commands without limit. 1. -bash-4.2# cat /usr/lib/systemd/system/path_c...
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Practical: FIO test with resource control. limiting resource with cgroup
This is a demonstration of using cgroup, now in RedHat 7 control group is administer with systemctl I will create a service running randow IO read and write. # cat fio.test1 [random-read] rw=randread numjobs=16 direct=0 filename=/dev/sdb1 group_reporting io...
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Connecting to SQLPLUS/ASMCMD...SP2-1503: Unable to initialize Oracle call interface/UNKNOWN OCI STATUS 1804 OCIInitialize
This error indicate improper set of environment variables.  here is a scenario. there are other out there... ERPDB1:/ERP1/11.1.0/ASM_1$ export ORACLE_HOME=/ERP1/11.1.0/ASM_1 ERPDB1:/ERP1/11.1.0/ASM_1$ export PATH=/ERP1/11.1.0/ASM_1/bin:$PATH ERPDB1:/ERP1/11...
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Connecting to SQLPLUS...SP2-1503: Unable to initialize Oracle call interface
This error indicate improper set of environment variables.  here is a scenario. there are other out there... ERPDB1:/ERP1/11.1.0/ASM_1$ export ORACLE_HOME=/ERP1/11.1.0/ASM_1 ERPDB1:/ERP1/11.1.0/ASM_1$ export PATH=/ERP1/11.1.0/ASM_1/bin:$PATH ERPDB1:/ERP1/11...
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ORA-04091: table ... is mutating, trigger/function may not see it
this error occurs often times when we are thinking about performance and neglecting the mechanisms that trigger rely on. simply checking the error code will bring us closer to the solution: # oerr ora 4091 04091, 00000, "table %s.%s is mutating, trigger/fun...
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ORA-03113: end-of-file on communication channel error AT STARTUP UPGRADE
This error was encounter during upgrade of 11.2.0.1 to 11.2.0.4. after change of oracle_home and path variables.  "sqlplus > startup upgrade" thrown error ORA-03113 Solution==== set LD_LIBRARY_PATH and SHLIB_PATH to the new oracle home location for example:...
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