i am sorry but i am getting mixed feeling and mixed answers.
It depends.
If you are solo mining (not mining in a mining pool), then YES, you have control over the transactions in your block.
If you are mining in a mining pool, then the pool will have control over the transactions in your block.
Note that this also means:
If you operate your own mining pool, and don't do any mining yourself (just rely on the participants in your pool to do the mining for you), then you will have control over the transactions in the blocks that ALL your pool participants work on.
so if i understand correctly. (correct me if i am wrong)
if my miners find a block i can decide which transaction to put in the block (up to 1mb transaction)?
for instance, i can do a transaction for 1 satoshi/B and if i find a block i can put that transaction inside it?
to find a block among all the pools its like almost impossible. am i right?
is there another way ? for small miners which dont have peta/exa hashing power?
why u have mention a node?
Theoretically yes - practically, it's very unlikely.
why? because i have to find a block first?
theoretically, if i find a block, how long can i hold it?
theoretically: if you can mine blocks then you can certainly include your own transactions in the block.
practically: you are competing with every other miner on the planet to find the next block. If it happen you get the block reward plus you get to choose which transactions are included in your block. and if somebody else wins you get no say in the matter Unless you have a very large mining operation, the chance of you winning is so small that it's never going to happen.
miiners who do make new blocks today may choose to include their own transactions in their blocks.
u mention the block reward,
the reward that u mention is 12.5 BTC? + selecting the transaction thats goes into block +getting the transaction fees? (again correct me if i am wrong)