Introduction 

A plugin that can efficiently export data from Oracle to be used as a source in Hydrator.  Oracle includes command line tools to export data  that can be utilized to perform this task.  

User Stories

• As a Hydrator User I want to export data from Oracle to be used in my hydrator Pipeline.
• As a Hydrator User I want a Oracle Export plugin that exports data efficiently using existing existing Oracle tools. 
• As a Hydrator User I want the export data capability of the Oracle plugin to be based on a sql query that I issue.  
• User should be able to specify credentials.
• Passwords should not be viewable in plain text from inside pipeline viewer or hydrator studio.  
• User should be able to specify Oracle Instance
• User should be able to specify location of EXP Utility.   
• User should be able to specify type of output.
• User should be able to specify location of output files.  
• User should know of connectivity errors, or malformed queries/output identifier.   

Example

User wants to export the data from test table using filter on name='cask' i.e Select * from test where name='cask'

Plugin configurations:

          "oracleServerHostname": "example.com",
          "oracleServerPort": "22",
          "serverUsername": "oracle",
          "serverPassword": "oracle@123",
          "dbUsername": "system",
          "dbPassword": "cask",
          "oracleHome": "/u01/app/oracle/product/11.2.0/xe",
          "oracleSID": "cask",
          "queryToExecute": "select * from test where name='cask'"

          "columnSeparator" : ","

                   "absolutePathOfOutputFileOnRemote" : "/tmp/results.csv"

                   "destination" : "/home/cdap/export"

Prerequisites on the DB server:

1.Directory should be configured on the server where we want to place the export files.

Steps could be:

CREATE OR REPLACE DIRECTORY test_dir AS '/u01/app/oracle/oradata/';
GRANT READ, WRITE ON DIRECTORY test_dir TO oracle;

2.param.par file should be already present and should contain below:

DIRECTORY = test_dir
DUMPFILE = table.dmp
TABLES = test
QUERY = test:"WHERE name = 'cask'"

3.On execution of plugin,table.dmp would be stored in the test_dir.

Implementation Tips

Design 

Design:

{
    "name": "OracleExportAction",
      "plugin": {
        "name": "OracleExportAction",
        "type": "action",
        "label": "OracleExportAction",
        "artifact": {
          "name": "core-plugins",
          "version": "1.4.0-SNAPSHOT",
          "scope": "SYSTEM"
      },
      "properties": {
          "oracleServerHostname": "example.com",
          "oracleServerPort": "22",
          "serverUsername": "oracle",
          "serverPassword": "oracle@123",
          "dbUsername": "system",
          "dbPassword": "cask",
          "oracleHome": "/u01/app/oracle/product/11.2.0/xe",
          "oracleSID": "cask",
          "paramFilePath": "/parameters/param.par"
      }
      }
}

oracleServerHostname:Host name of the remote DB machine where the data dump command is to be executed

oracleServerPort:Port of the remote DB machine to connect to.Defaults to 22

serverUsername:User name used to connect to remote DB host

serverPassword:Password used to connect to remote DB host

dbUsername:User name to connect to oracle DB

dbPassword:Password to connect to oracle DB

oracleHome:Path of the ORACLE_HOME

oracleSID:Oracle SID

paramFilePath:Full path of the PARAM file.Param file should contain required parameters to run data dump command.

 e.g If you want to export the data from test table using filter for name column-
  DIRECTORY = test_dir(This should be already configured and should have required access)
  DUMPFILE = table.dmp(dump file name)
  TABLES = test(tables on which data export needs to be done)
  QUERY = test:"WHERE name = 'cask'"

Plugin would perform below steps:

1.SSH to the box using the provided $serverUsername and $userPassword.

2.Run below commands:

a.export ORACLE_HOME = $oracleHome;

b.export ORACLE_SID = $oracleSID

c.$oracleHome+/bin/./expdp $dbUsername/$dbUserpassword  parfile=$paramFilePath

On comepletion of above commands,dump file would be generated in the DIRECTORY specified in param file.