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Limit of configured 'SharedSQLCommandCacheSize' (<size>KB ) reached!

<number_of> memory allocations failed for command cache. Allocated <usable_size>KB, configured <size>KB

Command cache hitrate <percentage>%, <number> of <number> accesses failed

<number_of> command cache cleanups! <number_of> commands reloaded, <number_of> execution plans and <number_of> commands deleted

Explanation

Beschreibungen prüfen und konkretisieren

The parameter  SharedSQLCommandCacheSize specifies the maximum size of the cache for Shared SQL. The cache is created with an intial size and can be enlarged by the cache management stepwise.

If the maximum size is reached older statements are removed by an LRU mechanism. If this is still not sufficient the cache will be enlarged in steps of 2 MB.


User Response

If you observe a lot of messages concerning accesses to the Command Cache check how the parameter is set and enlarge the cache.

A bad hitrate for this cache is not of the same importance as the hitrate of the data cache so usually there should not be high priority warnings. Nevertheless, if commands have to be reloaded too often, this will have an impact on the overall performance.


More Information

 

Relevant  DB-Analyzer FilesHelpful with ...
 DBAN_SHARED_SQL.csvStatistics about shared SQL (hit rates of the prepare cache, command cache, cleanup, unload)

  

SAP Notes 
1497862 - FAQ: SAP MaxDB Shared SQLDescribes the mechanism of shared SQL
Expert SessionsContent / Helpful with ...
  
Documentation (links) 
  
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