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From Apache Wiki <wikidi...@apache.org>
Subject [Db-derby Wiki] Update of "Derby3192Writeup" by DyreTjeldvoll
Date Mon, 21 Jan 2008 10:04:48 GMT
Dear Wiki user,

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The following page has been changed by DyreTjeldvoll:
http://wiki.apache.org/db-derby/Derby3192Writeup

------------------------------------------------------------------------------
  CNTQRY commands. Most of the overhead seems to come
  from the PKGNAMCSN instance variable which by itself uses 76 bytes, or
  59% of the total overhead:
-  
+ 
-  || DRDA VARIABLE || SIZE (BYTES) || 
+ || '''DRDA VARIABLE''' || '''SIZE''' (BYTES) ||
-  || DSS header || 6  ||
+ || DSS header || 6  ||
-  || EXCSQLSET  || 4  ||
+ || EXCSQLSET  || 4  ||
-  || PKGNAMCSN  || 76 ||
+ || PKGNAMCSN  || 76 ||
-  || RTNSETSTT  || 4  ||
+ || RTNSETSTT  || 4  ||
-  || HEXSTRDR   || 5  ||
+ || HEXSTRDR   || 5  ||
-  || SQLSTT     || 4 + 1 + 4 + 23(strlen) + 1 ||
+ || SQLSTT     || 4 + 1 + 4 + 23(strlen) + 1 = 33 ||
-  || TOTAL      || 128 ||
+ || TOTAL      || 128 ||
   
  This gives a total overhead of (a whopping) 128 bytes. 
  It can be reduced by shortening the name used for the "special
@@ -216, +216 @@

  `getDSSLength()`) increases to 65 after adding the SQLCARD (which creates
  its own DSS):
  
- || DRDA VARIABLE || SIZE (BYTES) ||
+ || '''DRDA VARIABLE''' || '''SIZE''' (BYTES) ||
  || DSS header    || 6            ||
  ||  SQLCARD      || 65           ||
- ||  SQLSTT       || 4 + 1 + 4 + (4+1)(strlen) + 1 (15) ||
+ ||  SQLSTT       || 4 + 1 + 4 + 5(strlen) + 1 = 15 ||
  ||   ...         ||  ...         ||
  || TOTAL         || 71/86        ||
  

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