[Marshas]

Hello everyone. Today I decided to start making my log system and I'm confused a little bit how should I do it. Should I use file management or MySQL? I would like to see advantages and disadvantages of these two ways, if someone can provide them. If file logging is the answer, which file writing/overwriting include/plugin should I use, which one is the best? If I want to have UCP on my website in future, could I load logs from files or I should use MySQL only? How can I store for ex. chat logs there? If I would like to check someone's conversation with other player (to detect IG money selling for IRL money lets say, illegal stuff), how can I log messages which are displayed on players chat, which came from other players? Detect getting messages in certain distance, which I would use in future for displaying messages over players heads (Chat bubbles, I hav'nt done almost anything in my gamemode, just preparing it for easier work in future). Sorry for my english mistakes if there are some. Thanks in advance!

EDIT:
Recently I tought about multiple mysql connection in my gamemode, one for main server purposes, accounts, houses, businesses, etc. The second for logs, there would be several tables, for chat logs, command logs, movement logs, money logs. Every table would have lets say at least 2 columns, ID of log (A_I) and the log itself ofcourse. Also I tought about foreign keys, and how could I use them if logs would be in the main database, but would it be query, information overflow? Help me decide guys, thanks.