Revert "content/en/docs/19.0: document QueryCache{Hits,Misses} stats (#…

…1663)"

This reverts commit d7e2589.

content/en/docs/19.0/user-guides/configuration-basic/monitoring.md

@@ -278,13 +278,9 @@ There are other internal pools used by vttablet that are not very consequential.
 
 The above three variables are table acl stats. They are broken out by table, plan and user.
 
-#### `QueryCacheCapacity`, `QueryCacheEvictions`, `QueryCacheHits`, `QueryCacheMisses`, `QueryCacheSize`
+#### `QueryPlanCacheSize`
 
-VTTablet maintains a cache of query plans, and instruments cache usage in `QueryCache*` stats.
-
-If the application does not make good use of bind variables, `QueryCacheSize` will reach the value of `QueryCacheCapacity`, at which point `QueryCacheEvictions` would increase. Monitoring the current `QueryCacheSize`will give you a clue about where the misuse is happening.
-
-`QueryCacheHits` and `QueryCacheMisses` provide visibility, respectively, into how many queries are being sped up by the cache or else have to fall back to the slower path of query parsing and planning.
+If the application does not make good use of bind variables, this value would reach the QueryCacheCapacity. If so, inspecting the current query cache will give you a clue about where the misuse is happening.
 
 #### `QueryCounts`, `QueryErrorCounts`, `QueryRowCounts`, `QueryTimesNs`