MYSQL query execution performance issue

I agree with Richard, your first issue with this is your design. There is no requirement that you can have the you would absolutely need to show all 150,000 records all at once.

But lets assume you are determined that it is 150k records or bust.

My first comment would be to look into paginating your data, i think mysql has the concept of LIMIT (I am rusty on my mysql) but would allow you to do something like SELECT * FROM <Table> LIMIT 5,10 which would let you get 5 records starting with the 5th record. I will tell you, none of your users are going to appreciate having to look at 150k records to try and find specifics of what they want. You are better to filter this data to the relevant result set than try and show it all at once, your users will hate you if they have to manually filter that data on their own.

Then you need to look at your servers hardware. 150k records in 8 hours is ridiculous. I can run a similar query in sql server (granted in different db platform) and get 150k records with a three table join in a few seconds. 8 hours for 150k records, are you running your DB on a single core with 500mb of RAM? So look into your hardware problems

Look into what you are querying. 8 hours for that many records, you must be pulling out 10,000 columns or something...are you doing some crazy aggregation that you can maybe offload by storing the data in the required aggregated manner to begin with? For example, If you always add 4 columns to create a total, why not just add a fifth column called "Total" and store that total there so your not having to do the math every time you query it out.

To go along with the last comment, you need to look at your query as well to see what, within your query, can be tuned. Are you doing sub queries unnecessarily? Could you utilize temp tables for some of your joins? Could some of your query that you are doing be unnecessary if you were to add more columns to your schema? I think mysql has the keyword called EXPLAIN that you can use in order to have your query profiled as it runs so you can analyze what is going on.

And I suppose finally, if you want help you need to post a sample schema and your queries so those that want to, can try and replicate your issue your having. Without that all we can do is guess and point you in directions of what you could possibly look at but without that...all you've done is gone to a doctor, tell them your sick, and expect them to diagnose you without having examined you.