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  1. WiredTiger
  2. WT-1439

exponential dhandle list traversal

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    • Type: Icon: Task Task
    • Resolution: Done
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      When opening a statistics cursor over a lot of tables we end up with exponentially worse performance. See SERVER-16353. The problem is that all time is spent in wt_session_get_btree traversing the dhandle list due to *wt_conn_btree_apply. 1000 tables takes 8 seconds, 3000 tables takes 84 seconds. As we open N tables, it loops in __wt_session_get_btree N+sum(1-N) times or N+(N(N+1)/2). For the 1000th open we are in that loop 501500 times, for the 3000th open we are in it 4504500 times for that one open_cursor call.

            Assignee:
            Unassigned Unassigned
            Reporter:
            sue.loverso@mongodb.com Susan LoVerso
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