PROBLEM
ArcMap or ArcCatalog are unable to establish a connection to the PostgreSQL database after ArcGIS 10.1 is upgraded to ArcGIS 10.2.x.
The error occurs due to missing PostgreSQL client libraries which are required by ArcGIS to connect to the PostgreSQL database. These files are located in the ArcGIS bin folder, and may have been deleted or replaced with an incorrect version when upgrading ArcGIS 10.1 to 10.2.
C:\Program Files (x86)\ArcGIS\Desktop10.2\bin
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