You can find your requested detals in the table - RSDDSTAT_OLAP .
UNAME - username who executed the query last tme .
OBJNAME - give you the query name .
just give your query name for the OBJNAME field , you will get the uname who executed it ( if it was executed) and the timestamp when it was executed .
Hope this solves your issue .
You need to setup the statistics, use transaction RSDDSTAT.
The statistics will then be stored in the table RSDDSTAT_OLAP for reports
Check table RSZCOMPDIR
ENTER TECHNICAL QUERY Name in RSZCOMPDIR-COMPID.
RSZCOMPDIR-TSTNAM gives you the user id of sap bw user who made the change.
RSZCOMPDIR-TSTPDAT gives you date on which change was made .
RSZCOMPDIR-TSTPTIM gives you timestamp on which change was made .
all users details can be obtained from TCODE SU01 where you need to enter sap user id.
You can also get user name( description) by using tcode SE09 and entering above sap user id.