How to calculate CDC cache size (-cdcsize) ? - Forum - OpenEdge RDBMS - Progress Community

How to calculate CDC cache size (-cdcsize) ?


How to calculate CDC cache size (-cdcsize) ?

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The documentation says: "For best performance, you should set CDC cache size (-cd size) large enough that all your existing records fit in the primary cache."

But what does this mean?

What kind of records are we talking about? about CDC policies? or about real records from tables?

How to calculate this size before using the CDC?

In promon, I see a new screen: R&D-> 4 -> 13. Caches

08/16/18        Status: Caches

 ID        Name      Size(kb)  Entries  Hash      Hits        Misses
--- ---------------- -------- -------- ------ ------------ ------------
  1 CDC Primary          1500        0   4759            0       822150
  2 CDC Secondary         500       10   1733       822143            7

What should I look at on this screen? What are Entries, Hash, Hits and Misses?


All Replies
  • Yesterday, a corresponding article was added to ProKB.

    Thanks to someone who did this.

    However, it does not clarify how to monitor this parameter. Does anyone have any ideas for this?

  • The cdcsize parameter (along with other db parameters) can be monitored in OEM.

    Go to the database resource-> Configuration-> default configuration. Under the Advanced tab, you will see the cdcsize parameter. You can edit the parameter here.

    To view all the database parameters including cdcsize, go to the database home page-> Database configuration (under Informational Views)

  • What are the symptoms/indicators that the size of CDC cache is not large enough?