[Koha-devel] Search speed

[Paul A]

At 02:02 PM 2/2/2015 +0000, Tomas Cohen Arazi wrote:
>Paul, while you are running your tests, could you please compare this both 
>scenarios:
>- <use_zebra_facets>1</use_zebra_facets>
>- <use_zebra_facets>0</use_zebra_facets>
>Thanks
>PS: I have found that searchResults is too slow too.

I have posted notes, results and some NYTProf examples at 
<http://navalmarinearchive.com/z_koha/> -- the results are repeatable (I 
must have run NYTProf nearly 200 times.)

Provisional conclusions are that <use_zebra_facets> = 1 (true) is not 
usable in production for a search that finds > 20k results. For smaller 
results, it might be acceptable, but is still appreciably slower than 3.08. 
Under the best circumstances (0-5 results) 3.08 responds in < 0.7 secs, 
3.18 in 1.3 secs.  At the other extreme (25k results), 3.08 requires 1.07 
secs, 3.18 21+ secs.

I have defined an "optimal" 3.18 combination (see green line, Graph 2) 
which runs at about half the speed of 3.08, but does not give 'Series', 
'Places' and 'Titles' in the facets.

One point that jumped out is that a best case 3.08 search executes 431207 
statements and 76556 subroutine calls in 297 source files and 81 string 
evals whereas a worst case 3.18 executes 1238167 statements and 309905 
subroutine calls in 591 source files and 132 string evals. (Even the worst 
case 308 appears much more efficient than the best case 3.18.)

The use of -T to start Zebra is non-conclusive -- it vaguely slows down 
smaller result sets and vaguely speeds up larger result sets (testing is 
repeatable.)  Robin was of course quite correct in his recent email, but I 
cannot explain even the minor variations experienced.

I'm not at all certain how to file this as a bug, so will await any comments.

Best -- Paul