it meens , the number of milliseconds spent waiting for io

Hi,

changing collation of only some columns get to some trouble

when comparing/joining two columns of different collation.

you need to use an explicit conversion which may lead to bad performance

(not using index...

I think that case sensitive database make use of binary sort order

that non case sensitive cannot.

It's more related with performance.

Hello,

It seems to me that IostallMs is not related to Number of Bytes Reads/Writes

but to the number of Read/Writes

So the last select, should be

SELECT TOP 5

DataBaseName,

TimeStamp,

SUM(NumberReads) + SUM(NumberWrites)...