query is taking different time in every execution in MSsql
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I have one table in sqlserver database.It is having 5 rows only.when i m running one query like "select * from Table",sometimes it takes 0 sec,sometimes it takes 5 sec,sometimes 10 sec,etc. and sometimes it just keep on executing and gives an error like


A transport-level error has occurred when sending the request to the server. (provider: TCP Provider, error: 0 - An existing connection was forcibly closed by the remote host.)

what can be the issue.I am just optimizing all my queries.but it is not taking fix time,how can i come to know that how much time it is taking.My site is opening in 2 sec,10 sec,2 min ,