Error Tables In Informatica

What -- Most of the time at the time of development or even in production, our workflows fails giving some error. Usually we do not keep track or these errors and fixing the issues we just ignore them. What if we want to keep track of these errors which occurred over a period of time?
Informatica provides the capability to track these errors.

How -- If you open a session task, then at ConfigObject tab you will find an Option called "Error Log Type"; By default this type is selected as None.

As you can see, you have 3 options available

1. None [Default]
2. Relational Database
3. Flat File

2. Relational Database -- When you select "Relational Database" option, informatica by itself will create 4 tables in the database you will choose.

As displayed in above image, you will have to specify Relational Connection on which you want to create these error tables.
Also, you can specify the prefix of these error tables which informatica is going to create.

Running Workflow --
After doing the above settings, after running the workflow, informatica will create 4 error tables as shown below

PMERR_TRANS
PMERR_SESS
PMERR_MSG
PMERR_DATA

If your workflow fails with some error, all 4 tables will have some data, however if you workflow gets succeeded only pmerr_sess will have data related to respective workflow.

If you again run the same workflow / any other workflow, informatica will check if the 4 error tables are already exists, and if those, it will use those tables to maintain the logs..

As you can see, informatica is using same tables again to maintain the log. It will append the new entries into an existing tables.