Posts

How to Install Maven on Mac OS

  Installing Maven on MacOS Go to https://maven.apache.org/download.cgi and search for the right version. Download the tar file using command below $ wget https://dlcdn.apache.org/maven/maven-3/3.9.0/binaries/apache-maven-3.9.0-bin.tar.gz   Untar the file and move the folder to Mac OS Java location $ tar -xvf apache-maven-3.9.0-bin.tar.gz Set environment variable to be able to use java from any location by adding the following to .bash_profile $ vi $HOME/.bash_profile M2_HOME="/Users/xxx/Downloads/apache-maven-3.9.0" PATH="${M2_HOME}/bin:${PATH}" export PATH Restart the shell or source the bash_profile

How to Install Java on Mac OS

Installing Java on MacOS We will install OpenJDK which is free and doesn't need Oracle JDK licence. Go to https://jdk.java.net/19/ and search for the JDK version. Download the tar file using command below $ wget https://download.java.net/java/GA/jdk19.0.2/fdb695a9d9064ad6b064dc6df578380c/7/GPL/openjdk-19.0.2_macos-x64_bin.tar.gz Untar the file and move the folder to Mac OS Java location $ tar -xvf openjdk-19.0.2_macos-x64_bin.tar.gz $ sudo mv jdk-19.0.2.jdk /Library/Java/JavaVirtualMachines/ Set environment variable to be able to use java from any location by adding the following to .bash_profile $ vi $HOME/.bash_profile JAVA_HOME="/Library/Java/JavaVirtualMachines/jdk-19.0.2.jdk/Contents/Home" PATH="${JAVA_HOME}/bin:${PATH}" export PATH Restart the shell or source the bash_profile

Connecting to Oracle Autonomous Database from SQL Developer

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Step 1: Download the Wallet from ATP database console. Step 2: Launch SQL Developer. Step 3: Click on File > New > Database Connection Step 4: Enter the details

Oracle SQL Developer 19.4 font too small

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I downloaded the latest version of Oracle SQL developer on my windows laptop and when I started it, the font on GUI was too small. To fix the font size scroll to the bottom of the  'Welcome Page' and uncheck 'show on startup'. Restart the SQL Developer and issue will be fixed.

ORA-00018: maximum number of sessions exceeded

You receive the following errors when trying to make new connections using SQL Developer or any other client: ORA-00018: maximum number of sessions exceeded Resolution: Login as sysdba  $ sqlplus / as sysdba SQL*Plus: Release 12.1.0.2.0 Production on Tue Apr 28 03:32:48 2020 Copyright (c) 1982, 2014, Oracle.   All rights reserved. Connected to: Oracle Database 12c Standard Edition Release 12.1.0.2.0 - 64bit Production SQL>   Check the resource limit SQL> set lines 256 SQL> set trimout on SQL> set tab off SQL> select * from v$resource_limit; RESOURCE_NAME                   CURRENT_UTILIZATION MAX_UTILIZATION INITIAL_ALLOCATION                       LIMIT_VALUE                                   CON_ID ----------------------...

Oracle Cloud - Free Tier

For the cloud enthusiast who wants to explore and start the journey to the Oracle Cloud, Oracle offers free version of various IaaS and PaaS services. In this post, I will discuss how to provision Autonomous Database, VM and Load Balancer on Oracle Cloud. What is Free Trial Oracle provides you with $300 of cloud credits that are valid for up to 30 days when you sign-up. You may spend these credits on any eligible Oracle Cloud Infrastructure service (OCI). After your trial ends, your account remains active. There is no interruption to the availability of the Always Free Resources you have provisioned. You can terminate and re-provision Always Free resources as needed. Paid resources that were provisioned with your credits during your free trial are reclaimed by Oracle unless you upgrade your account. What is always Free resources All OCI accounts (whether free or paid) have a set of resources that are free of charge for the...

AWS Simple Storage Service S3

Some of the key notes related to S3 from AWS documentation Amazon S3 has a simple web services interface that can be used to store and retrieve any amount of data, at any time, from anywhere on the web. Amazon S3 Data Consistency Model Amazon S3 provides  read-after-write consistency for PUTS of new objects  in your S3 bucket in all Regions with one caveat. The caveat is that if you make a HEAD or GET request to the key name (to find if the object exists) before creating the object, Amazon S3 provides eventual consistency for read-after-write. Amazon S3 offers  eventual consistency for overwrite PUTS and DELETES  in all Regions. Updates to a single key are atomic . For example, if you PUT to an existing key, a subsequent read might return the old data or the updated data, but it never returns corrupted or partial data. Amazon S3 achieves high availability by replicating data across multiple servers within AWS data centers. If a PUT request is successful...