Some general guidelines for page compression are:
Query operations such as filtering, joins, aggregates, and sorting see decompressed data, and hence the cost of these operations arenot affected by data compression.
A query, whose cost is dominated by complex processing operations is muchless likely to see any significant change in performance or CPU utilization, due to data compression.
If CPU time for an application consists primarily of complex queries, page compression maynot impact CPU measurably. In such scenarios, space savings may be the prime driver for data compression.
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In my understanding, page compression consumes much CPU than row compresssion, so the cost of query operations such as filtering, joins, aggregates should be affected bypage compression. But the white papers says not. Why?