I'm dealing with a Postgres table (called "lives") that contains records with columns for time_stamp, usr_id, transaction_id, and lives_remaining. I need a query that will give me the most recent lives_remaining total for each usr_id There are multiple users (distinct usr_id's) time_stamp is not a unique identifier: sometimes user even...
I always thought that a node in an execution plan can only be executed after its children have executed, and thus the total cost of a node has to be greater or equal than the cost of the child nodes. However, this is not always the case, like in the following example: Plan hash value: 2810258729 ----------------------------------------...
Hello, I have a cost optimization request that I don't know how if there is literature on. It is a bit hard to explain, so I apologize in advance for the length of the question. There is a server I am accessing that works this way: a request is made on records (r1, ...rn) and fields (f1, ...fp) you can only request the Cartesian prod...