Rule of Thumb for Estimating Concurrent DB Connections on a 24-Core Machine (Single Thread Each) The number of concurrent database connections a 24-core machine can handle depends on various factors, including: Hypothetical Calculation Based on CPU A single-threaded, single-core system can typically handle 2-10 concurrent active queries (depending on execution time and parallelism). For a…
In an Oracle Exadata environment, cell node storage disks are presented to compute nodes as ASM disks, and this mapping occurs through the Oracle ASM (Automatic Storage Management) and Exadata Storage Server software (CellCLI). Here’s a detailed explanation of how the cell node storage disks are mapped to the compute nodes: 1. Cell Node Storage:…
In this guide, I’ll walk you through moving SQL profiles using a staging table. SQL profiles help databases optimize query execution plans. Step#1 Create the Staging Table First, create a staging table to hold SQL profiles that need to be transferred. SQL> exec DBMS_SQLTUNE.CREATE_STGTAB_SQLPROF(table_name => ‘SQL_STG_TAB’, schema_name => ‘SYS’); This will create a table SQL_STG_TAB…
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When dealing with Oracle 19c Real Application Clusters (RAC), the process of capturing a workload from a source Oracle 19c RAC database and replaying it on a target Oracle 19c RAC database using HammerDB involves some additional considerations. Below are the revised steps: Capture and Replay Workload from Source to Target Oracle 19c RAC Download…
DB Users are required to reset the password periodically for better security. For some service accounts, we need to make sure the password does not expire and does not impact the application. For this purpose, we need to update that user’s Profile. Each Profile has multiple security settings that controls Password_life_time, password_reuse_time, password_reuse_max settings. These…
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Converting rows to single column: create table emp ( empno number, empname varchar2(100), deptno number); insert into emp values( 1, ’emp1′, 10); insert into emp values( 2, ’emp2′, 20); insert into emp values( 3, ’emp3′, 30); insert into emp values( 4, ’emp4′, 10); insert into emp values( 5, ‘paresh’, 30); insert into emp values( 6,…
Run following query as sysdba. alter session set nls_date_format=’DD-MON-RRRR:HH24:MI:SS’; alter session set nls_date_format=’DD-MON-RRRR:HH24:MI:SS’; select username, created, account_status /* Users who granted role with DML privs */ from dba_users where oracle_maintained = ‘N’ and username in (select grantee from dba_role_privs where granted_role in (select role from dba_roles where role in (select GRANTEE from dba_tab_privs where privilege…
Following script will be useful for tracking Oracle GoldenGate replicat process and related lag. This script will generate output on standard screen. You can redirect it using file redirection to logfile or other locations. while true do <goldengate home directory>/ggsci <<EOF > test.out info all exit EOF lag=`cat test.out | grep TESTREPLICAT | awk ‘{print…
If you want exclusive lock on any table, you need to make sure that no other session is accessing it. This happens when you want to run DDL or any ALTER statements, that internally needs exclusive lock. Following script will to find the blocker session and provide killing statement for clearing locks. col owner format…
On reporting queries, there are too many “enq: KO – fast object checkpoint” wait event. All reporting queries are doing full table scans concurrently. Oracle uses direct path reads instead of db file scattered reads. And direct path reads require a checkpoint “_serial_direct_read”=NEVER Parameter Session Value Instance Value ————————————————– —————————— —————————— _serial_direct_read auto auto