You can use PostgressSQL versions as 9.3, 9.4, 9.5 or 9.6 for Pega 7.4.
The same way, use JDK 1.8. here initially I used JDK 1.10, then downgrade to JDK 1.8.
You should keep pljava.jar and pljava.dll from ResourceKit\PLJava folder to the installed PostgreSQL\9.6\lib\ folder. Then do the changes in PostgreSQL\9.6\data\postgresql.conf like follows: (location can be changed based on your installation)
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