using mongodb to store application logs vs RDBMS

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hi all

i did done some homework about the different between rdbms and nosql and the difference between postgressql and mongodb but i am still not sure which database to use for logs storing purpose and other factors e.g. HA and ease of setup/maintaining

hope to hear some advice from the folks here

  1. i am on oracle RAC with dataguard on

  2. the IT team is treating the database as application log dump for the reason that it is easier to search for logs

  3. the database is growing very big and bulky due to all these logs which affect the standby sync

  4. these logs are not mission critical and do not require complete join / relation

  5. i am not able to stop them from logging and i need to provide an alternative database to store the logs

  6. we have explore other options such as ELK but please just treat it as logging to database is still preferred

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  1. any idea on what database should i use ? will nosql database do better here ? since there are alot of different kind of application logs and they can be shard by country / app etc

  2. is mongo easier to setup then postgres ? does mongo generated less redo ? i still need the HA but it is not as important

  3. should i just use any rdbms for this log storing purpose ? or nosql database does really have an edge here ?

Thank you