getDbDiskCacheStats

getDbDiskCacheStats(jdo: JadeDynamicObject input);

The getDbDiskCacheStats method of the System class returns statistics relating to the persistent database cache. The values are returned as Integer64 properties in the dynamic object specified by the jdo parameter. For details about the properties returned in the dynamic object, see "System::getDbDiskCacheStats Method", in Chapter 4 of the JADE Object Manager Guide. For further explanation of these values, refer to the JADE Monitor knowledge base.

The calling process is responsible for creating and deleting the JadeDynamicObject instance. Properties are added to the object when the method is first called. The object can then be used in subsequent calls.

If the dynamic object passed to the method already contains properties that do not match the properties to be returned, the existing dynamic object properties are removed and replaced with the appropriate properties. This method is most efficient when the properties match those to be returned.

The cumulative values are held as 64-bit unsigned integer values, and are copied to the dynamic object as Integer64 values. The maximum value before they wrap around to negative values is therefore 2^63 - 1 (approximately 8 Exabytes).

The following example shows the use of the getDbDiskCacheStats method.

showDbDiskCacheStats();
vars
   jdo : JadeDynamicObject;
begin
   create jdo transient;
   system.getDbDiskCacheStats(jdo);
   write jdo.display;
epilog
   delete jdo;
end;

The output from the showDbDiskCacheStats method shown in the previous example is as follows.

---DatabaseDiskCacheStatistics(210)---
cacheMisses = 21
gets = 8162
puts = 331
blockReads = 8
getsWithFetch = 0
putsWithFetch = 0
blocksFetched = 1258
blockReadsMultiple = 333
bufferReassigns = 0
bufferSteals = 0
maxHashCollisions = 0
maxConcFlushIos = 15
blockWrites = 4
blockWritesMultiple = 111