Oracle 23c New Features for DBA'sAPACOUC Webinar 2018 – Wave 2 Sessions In next 2.5 hrs , @apacouc @fcomunoz @DataIntensity , I am presenting SQL Plan Stability & Flexibility Features
Register for free
https://events.genndi.com/register/818182175026319207/528ad96d7a
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Hello All, What wait event you observe when Oracle Performs a full table scan? DB File Scattered Read Direct Path Reads (from 11g onwards under certain conditions) What wait event you observe when Oracle Performs a table via index scan? DB File Sequential Read While we are working a issue, we apparently found an issue […] In the Previous Posts , to troubleshoot the problematic queries/long running session issues, we have sorted out two approaches, Here we discuss the Method 1 Method 1. Session Wait Event Approach:- In this approach we will try to identify from the problematic session what its waiting for , why its waiting, what can be […] In this part of the series, we will be looking into , how to identify the Problematic Sessions or Queries. Before beginning, one should distinguish the question here. You may face questions like, and the answer for both is to identify either loaded sessions for a database. 1. Database is/was slow.
In the previous series we have seen how to troubleshoot IO, CPU and Database TimeSpent/Consumed, Today’s Post I will be sharing with you the most common issues or to tackle memory related questions. As we all know Oracle does manage things (blocks/modifications) in memory and track them in memory and sort them in memory and […] Hello, This is the third post in this series, If you haven’t read the previous articles please go through here, First Post, http://db.geeksinsight.com/2015/10/08/performance-troubleshooting-series-understanding-your-oracle-database-load/ Second Post, http://db.geeksinsight.com/2015/10/09/performance-troubleshooting-series-understanding-your-database-load-from-metrics-part-2/ Starting 10g, Apart from Metrics tables, there is another area of troubleshooting can be done by using Time Model series. Its very useful to understand where is the over […] Hello, Very long back, Karlarao has written a wonderful script which delivers a exhaustive report for database performance. The script extracts the data from AWR repository tables. Where in I have took liberty to tweak the same script for those who does not have AWR licensing and having statspack only. Here is the script […] Today I learnt something new, on sql profiles. Thanks to Kerry Osborne’s blog that let me understand on this stuff Before going forward have a look at the below plans. SQL> select * from table(dbms_xplan.display_awr(‘2pg20pzpc6yb7’)); PLAN_TABLE_OUTPUT- —————————————————————————————————– SQL_ID 2pg20pzpc6yb7 ——————– SQL Statement removed intentionally, and it is irrelevant to subject Plan hash value: 526584108 —————————————————————————————————————————– […] During a query’s cost estimation the optimizer picks up many values or parameters to evaluate cost or invoke hints etc to produce an execution plan. v$sess_optimizer_env is a good view to know about any anamolies of a given statement. This can be useful when you comparing UAT and production environment where the query results are […] As per documentation its 30 seconds The parameter is (from 11gr2) is parallel_min_time_threshold which invokes the automatic degree of parallelism when the query execution goes beyond 30 seconds. Nevertheless, whether you have object parallelism (table/index degree) set or not, if parallel_degree_policy is set to Limited or Auto, Oracle uses parallelism for any queries depends on […] |
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