Speedup with history-db

[Eli Zaretskii]

> Date: Tue, 07 Jun 2011 14:28:18 +0200
> From: John Arbash Meinel <john at arbash-meinel.com>
> CC: bazaar at lists.canonical.com
> 
> Unfortunately, I cannot reproduce this. I see the short form in both
> cases. I'm curious why we would be getting different results.

Different versions of bzr, perhaps?  Mine is 2.3.3.

> One thing you could try, is "bzr log -Dhistory_db". It puts a little bit
> of extra info to stdout. I don't know if it will be enough or not, but
> it might help. (It might at least indicate if we are picking a random
> revision, etc.)

Here's the output about the last merge-commit I did to the Emacs
trunk, just a few minutes ago, showing a few first lines from the
revisions it lists that shouldn't have been there:

 D:\gnu\bzr\emacs\trunk>bzr log -Dhistory_db -c104529 --include-merges
 history_db rev=>dotted [(104529,)] took 0.012s, 0.010s to init, 0.001s to query
 history_db rev=>dotted cached (104529,)
 history_db iter_merge took 0.003s (0.003s query)
 104529: Eli Zaretskii 2011-06-07 [merge] Fix the MS-DOS build broken by STRI...
   104525.1.1: Eli Zaretskii 2011-06-07 Fix the MS-DOS build broken by STRING...
 104525: Eli Zaretskii 2011-06-07 nt/ChangeLog: Fix a typo in last entry.
 104523: Glenn Morris 2011-06-07 Auto-commit of generated files.
 104522: martin rudalics 2011-06-07 Install some window-size related function...
 104521: Paul Eggert 2011-06-07 [ChangeLog]
 [many more lines elided]

Here's the debug output with the other 2 revisions that exhibit the same
behavior:

 D:\gnu\bzr\emacs\trunk>bzr log -Dhistory_db -c104363 --include-merges
 history_db rev=>dotted [(104363,)] took 0.159s, 0.028s to init, 0.132s to query
 history_db rev=>dotted cached (104363,)
 history_db iter_merge took 7.022s (7.022s query)

 D:\gnu\bzr\emacs\trunk>bzr log -Dhistory_db -c104482 --include-merges
 history_db rev=>dotted [(104482,)] took 0.012s, 0.010s to init, 0.002s to query
 history_db rev=>dotted cached (104482,)
 history_db iter_merge took 0.049s (0.049s query)

TIA