Hi Erdal,

in this case, you’ll either need to wait, or think about sponsoring
the feature to speed up its implementation… ;)

Best,
Christian
___________________________

> Hi Christian,
> In this case, BaseX is embedded in a Java application (Eclipse RCP) and
> provides "live editing" of parts of big XML files (managed by BaseX). Just
> imagine we have an O(n^2) algorithm which visits 100x100 "data items" while
> executing 10 different (and "simple") expressions (in the inner loop). That
> would be 100x100x10 = 100'000 parsing/compiling operations taking in sum
> 5000 ms if 1 parsing/compiling operation takes 0.05 ms. If the expressions
> would be cacheable, then, maybe it would just take 10 x (0.05 ms + (lookup
> of compiled expression))
> Of course, O(n^2) is bad, but that is another story.
>
> The idea is to be able to cache compiled expressions (like parsing/compiling
> regex in java).
>
> Thanks!
>
>
> 2013/10/22 Christian Grün <christian.gruen@gmail.com>
>>
>> Hi Erdal,
>>
>> parsing and compilation phase is pretty fast in BaseX. Before you
>> think about precompiling your queries, it would be interesting to know
>> if parsing and compilation is a real bottleneck.. Have you already
>> done some profiling?
>>
>> The following example of running a (very simple) query 100'000 times
>> demonstrates that there may be no need to cache queries that are to be
>> executed multiple times:
>>
>> basex -V -r100000 "1+2"
>>
>> Parsing: 0.04 ms (avg)
>> Compiling: 0.01 ms (avg)
>> Evaluating: 0.0 ms (avg)
>> Printing: 0.03 ms (avg)
>> Total Time: 0.08 ms (avg)
>>
>> In a complex query with lots of modules being imported, however, the
>> time for parsing and compiling a query may increase. For those cases,
>> we indeed have some plans to precompile queries in the background. I
>> can’t give you a timeframe yet.
>>
>> Christian
>> ___________________________
>>
>> 2013/10/22 Erdal Karaca <erdal.karaca.de@gmail.com>:
>> > Hi all,
>> > We have lots of non dynamic (i.e. do not change at run-time)
>> > queries/expressions that are always parsed/compiled using a new
>> > QueryProcessor instance.
>> >
>> > How to cache compiled expressions for use with QueryProcessor?
>> > Or can we just cache QueryProcessor instances? If yes, are
>> > QueryProcessor
>> > instances thread-safe?
>> >
>> > Thanks!
>> >
>> > _______________________________________________
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>> > BaseX-Talk@mailman.uni-konstanz.de
>> > https://mailman.uni-konstanz.de/mailman/listinfo/basex-talk
>> >
>
>