Oracle SQL Explain Plan

Display the execution plan stored in the plan table. We are not executing the actual SQL.

EXPLAIN PLAN
    FOR SELECT /*+ gather_plan_statistics */
               COUNT (*) FROM dba_objects;

SELECT * FROM TABLE (DBMS_XPLAN.display (format => 'TYPICAL'));

Displays the actual execution plan used to run a query stored in the cursor cache. We have to execute the SQL first.

SELECT /*+ gather_plan_statistics */
       COUNT (*) FROM dba_objects;

SELECT * FROM TABLE (DBMS_XPLAN.display_cursor (format => 'ALLSTATS LAST +cost +bytes +peeked_binds'));

Upgrade ORDS in OCI

Update ORDS

yum -y update

Fix ords.conf

yum update will mess up the ORDS config file. We need to remove the extra ORDS_BASE_PATH.

vi /etc/ords/ords.conf

# ORDS Service Script Configuration File (ords.config)
#
# This file should be placed in the same folder as the ORDS Service Script
# (ords.sh). Following are the properties that can be set via this file:
#
# ORDS_CONFIGDIR  The absolute path to an ORDS configuration directory. If set
#                 and not empty then the script will overwrite the configdir
#                 property in the ords.war file located next to the script
#                 whenever the script is called with the start parameter.
# JAVA_HOME       The Java base path to be used when starting ORDS. It should
#                 contain the binaries folder "bin" and the "java" executable
#                 under it. If the path provided does not exist, is not
#                 readable or doesn't contain the "bin/java" executable, then
#                 the PATH's java binary will be used to determine the
#                 JAVA_HOME.
# JAVA_OPTIONS    A string containing the Java options to be passed to the JVM
#                 when starting ORDS. Parameters should be in a single line
#                 separates by spaces just as they'd be when invoking a JVM
#                 from the command line. No shell expansions are performed. No
#                 options are passed by default to the ORDS' JVM.
# ORDS_BASE_PATH  The base path for ORDS installation by default is /opt/oracle
#                 but if the rpm was installed with --prefix [path] to relocate
#                 the package this variable will track the installation path.

#####Example#####
#ORDS_CONFIGDIR=/opt/oracle/ords/conf
#JAVA_HOME=/usr/java/jre1.8.0_211-amd64/
#JAVA_OPTIONS=-Dsecurity.forceHTTPS=true
ORDS_BASE_PATH=/opt/oracle
ORDS_BASE_PATH=/opt/oracle

Run ORDS and setup the config directory

ords standalone and enter /opt/oracle/ords/config