What are the unary operator of the relational algebra?

Match the personality traits with their description

Jason works as an accountant in a department store. he needs to keep a daily record of all the invoices issued by the store. which file naming convention would him the most? a)give the file a unique name b)name the file in yymmdd format c)use descriptive name while naming the files d)use capital letters while naming the file

People with high self-esteem: accept their strengths and weaknesses. believe that failed experiences are failures of their whole self. feel good about who they are only when they reach total success. need positive external experiences to counteract negative feelings that constantly plague them.