Output

The Cache Wizard output contains five main sections for each cache. This is followed by a recommendation section and a legend section at the end of the report. The three main sections for each cache are:

cache section provides summary statistics for a specific cache:
```
------------------
default data cache
------------------
Run Size        :   100.00 Mb   Usage%              :      2.86
LR/sec          :    41.10      PR/sec              :     22.57  Hit%:  45.09
Cache Partitions:        4      Spinlock Contention%:      0.00 
```
Usage%

Each time a set of pages is brought into the cache, it is tracked track if that page gets is referenced (used). Once the page is removed from the cache this count gets reduced. This value gives the current usage of the cache as a % of the cache size.

LR/sec

A logical read is any read in a read from the cache (hit) or a disk read (miss). LR/sec is the number of logical reads in the cache during the interval divided by the sample interval.

PR/sec

A physical read is a read from disk (miss). PR/sec is the number of physical reads in the cache during the interval divided by the sample interval.

Hit%

Ratio of the hits to total cache reads, such as the ratio of (LR/sec - PR/sec) to LR/sec
Buffer pool section breaks down the 'cache section' statistics into the various buffer pools in the cache.
```
Buffer Pool Information 
-----------------------------------------------------------------------
IO Size Wash Size Run Size APF%   LR/sec   PR/sec   Hit%   APF-Eff% Usage% 
------- ---------- ------- ------ ------- -------- ------ -------- ------ 
4 Kb     3276 Kb    16.00 Mb  10.00     0.47     0.13  71.43    n/a     0.20
2 Kb    17200 Kb    84.00 Mb  10.00    40.63    22.43  44.79    n/a     3.37 
```
APF-Eff% ratio between pages brought for the account of Asynchronous Prefetch (APF) and used, to the number of pages brought in account of APF.

Usage% is similar to the Cache section, tracks if a page brought into the buffer pool is referenced or not. This gives the ratio of the pages referenced in the buffer pool to the run size of the buffer pool.

Object section reports statistics on the objects occupying the cache at the end of the interval. The output of this section can be limited by using the topN parameter. The objects are always displayed in the ascending order of PR/sec.

Object Statistics
-----------------------------------------------------------------------
Object                          LR/sec  PR/sec  Hit%   Obj_Cached% Cache_Occp% 
------------------------------- ------- ------- ------ ----------- ----- 
empdb.dbo.t1                      0.57    0.30  47.06       56.25        0.02
empdb.dbo.t2                      0.30    0.30   0.00       56.25        0.02
empdb.dbo.t3                      0.30    0.30   0.00       56.25        0.02

Object                          Obj Size    Size in Cache 
------------------------------- ----------- ------------- 
empdb.dbo.t1                         32 Kb       18 Kb   
empdb.dbo.t2                         32 Kb       18 Kb   
empdb.dbo.t3                         32 Kb       18 Kb

Recommendations section gives a set of recommendations where applicable based on the data collected in the sample interval:

The various recommendations are as follows: 
Usage% for 'default data cache' is low (< 5%) 
Usage% for  4k buffer pool in cache:default data cache is low (< 5%)
Consider using Named Caches or creating more cache partitions for
'default data cache' or both
Consider increasing the 'wash size' of the 2k pool for 'default data cache'
Consider adding a large I/O pool for 'default data cache'

Legend explains the various terms used in the output. Some of the terms from the output are explained here in greater detail.