Hash Totals

Hash Total is the term applied to the SLIK feature of verifying that the data transferred has been copied correctly. This is performed as a post-transfer step that queries the totals of user specified columns on both the source and destination tables.

Following the transfer the SLIK server performs this verification as two separate SQL SELECT statements on the source and destination tables. The SLIK server compares the results of the hash totals and reports any variances by e-mail. The variances are also written to a SLIK database table for later reporting.

Following is a list of Hash Total functions:

Operator	SQL Function
Count	Count(ColumnName)
Sum	Sum(ColumnName)
Max	Max(ColumnName)
Min	Min(ColumnName)
Avg	Avg(ColumnName)

During processing of a Column Map transfer the SLIK server checks to see if any Hash Total Operators have been specified on the columns. If present, SLIK constructs and executes an SQL statement like:

SELECT COUNT(*), Operator (ColumnName) [, …Operator(Column Name)]
FROM Table Name
WHERE Where Condition

on both the source and destination tables. The Where Condition can vary depending on how the Table Map SrcWhereCondition and DstWhereCondition have been configured.

Note: the COUNT(*) function (number of rows) is implicit in a Hash Total.