1. Evaluate the following relational algebra expressions; your answers must include the column header with the attribute names. Note: technically, the relational algebra deals with sets of tuples. Sets do not keep duplicate elements, so don't show them in your answers. (Many real RDBMSs do allow duplicates.) (a) TEMP_INITIAL (EMPLOYEE) (b) OEMP-INITIAL='W'(EMPLOYEE) (c) TEMP.INITIAL,STORE.CODE(OSTORE_CODE>EMP-CODE(EMPLOYEE)) (d) STORE -- REGION (e) TREGION_CODE,STORE_CODE(STORE ~ REGION) (f) TREGION_CODE,STORE_NAME(STORE) U REGION (g) REGION (STORE DA ASTORE_CODE,EMP_LNAME(OSTORE_CODE>YOLC EMP_CODE Table name: STORE STORE_CODE STORE_NAME 1 Access Junction 2 Database Corner 3 Tuple Charge 4 Attribute Alley 5 Primary Key Point STORE_YTD_SALES REGION_CODE 1003455.76 1421987.39 986783.22 944568.56 2930098.45 NNN Table name: REGION REGION_CODE REGION_DESCRIPT 1 East 2 West