Hi John,

I'm happy to hear that FastBit reached 1.3.0. It's been a lot of improvements 
over 1.2.8 !
I'm testing right now r511 (i guess it is the same as the stable release).
So far, it behaves like r510 did for me: stable and fast !

I noticed something strange in the packaging however, it seems that there are 
some differences between the repository at r511 are and the zip:
--- r511
+++ ibis1.3.0
-contrib/fbmerge/.deps/fbmerge.Po
-doc/contact.html
-doc/header.html
-doc/rara.html
+src/._colValues.cpp
+src/._colValues.h
-src/fastbit-0.7.pc.in
+src/fastbit-config.h
-tests/scripts/star2002.sh
+win/._MinGW.mak
-win/static_pthread_init.c
-win/static_pthread.patch
-win/xMinGW.mak

While we are at it, i have a small fix to push to xMinGW.mak (since we rename 
it, we have to change the following line):

fastbit.dll: $(FRC)
-       $(MAKE) -f MinGW.mak DEF="$(DEF) -DCXX_USE_DLL -DDLL_EXPORT" $(OBJ)
+       $(MAKE) -f xMinGW.mak DEF="$(DEF) -DCXX_USE_DLL -DDLL_EXPORT" $(OBJ)

These are only minor things, i don't think it is really worth changing for 
1.3.0.

Thanks,

-----Original Message-----
From: K. John Wu [mailto:[email protected]]
Sent: Monday, April 02, 2012 11:32 PM
To: Dominique Prunier
Cc: FastBit Users
Subject: Re: [FastBit-users] PATCH: perf boost on top of r501

Hi, Dominique,

Here is the link to the latest stable release
<https://codeforge.lbl.gov/frs/download.php/389/fastbit-ibis1.3.0.tar.gz>

Let me know spot anything that needs attention.

Thanks for all the help.

John



On 4/2/12 6:51 AM, Dominique Prunier wrote:
> Hey John,
>
> I just tested r510 and i'm please to say that not only it passes all my test 
> cases (with -DFASTBIT_EMPTY_STRING_AS_NULL), but it is also unbelievably 
> faster (more than 25% in my test) ! I'm not sure exactly why but this is 
> greatly appreciated. Could it be the move from the simple loop in 
> category::patternSearch to the much more sophisticated index::sumBins ?
>
> Do you have a lot of thing to change before the stable release ? I admit that 
> i'd prefer use a stable release too rather than r506.
>
> Thanks,
>
> -----Original Message-----
> From: K. John Wu [mailto:[email protected]]
> Sent: Saturday, March 31, 2012 1:33 AM
> To: Dominique Prunier
> Cc: FastBit Users
> Subject: Re: [FastBit-users] PATCH: perf boost on top of r501
>
> Hi, Dominique,
>
> I have added a couple of more test cases involving special characters
> in the test suite used by 'make check'.  The latest SVN revision is 510.
>
> Things seem to work OK.  I would like to wrap things for a stable
> research soon.  If you find anything that needs attention please let
> me know.
>
> John
>
>
> On 3/29/12 1:23 PM, Dominique Prunier wrote:
>> Hey John,
>>
>> I found the problem. When the exact value doesn't exists in the dictionary, 
>> operator[] is supposed to return size()+1 but here it returns 3 instead of 2 
>> (it returns raw_.size()+1 instead of key_.size()+1) which make the following 
>> code fail in dictionary::patternSearch:
>>
>>     if (!meta) {
>>         uint32_t code = operator[](prefix.c_str());
>>         if (code != size() + 1) {
>>             matches.push_back(code);
>>         }
>>         return;
>>     }
>>
>> We probably never saw it before for at least 3 reasons:
>>  * it only affects linear search from dictionary::operator[] since in the 
>> other case it returns raw_.size() so it can't happen is the dic is larger 
>> than 16
>>  * index::getBitvector that was previously used in category::patternSearch 
>> validate the given index and return 0 if it is out of bounds
>>  * category::patternSearch was validating that index::getBitvector didn't 
>> return NULL
>>
>> Thanks,
>>
>> -----Original Message-----
>> From: K. John Wu [mailto:[email protected]]
>> Sent: Thursday, March 29, 2012 3:48 PM
>> To: Dominique Prunier
>> Cc: FastBit Users
>> Subject: Re: [FastBit-users] PATCH: perf boost on top of r501
>>
>> Hi, Dominique,
>>
>> The query seg faulted in r507 because ibis::dictionary::patternSearch
>> placed the number 3 into the output array, however, the dictionary has
>> only one value "\"val%\"".  This creates an opportunity for
>> ibis::index::sumBins attempt to access bits[3], but there are only two
>> values in bits.  Any idea why is ibis::dictionary::patternSearch
>> producing 3?
>>
>> John
>>
>>
>> On 3/29/12 10:05 AM, Dominique Prunier wrote:
>>> Hey John,
>>>
>>> I'm sorry, my test case was not really "minimal" and too complex for what i 
>>> wanted to show you.
>>> Please don't change the escaping, the query evaluation works just fine.
>>>
>>> Just for your information, this test case was here to validate one thing: 
>>> consistent de-escaping in all layers:
>>>  - C source : "'\"val\\\\%'"
>>>  - Compiled : '"val\\%'
>>>  - After lexer : "val\\%
>>>  - In qLike : "val\%
>>> Ultimately, this tests try to validate that % escaping works in 
>>> patternMatch by not treating % as a wildcard but as a regular character, 
>>> thus this is not supposed to return any match (it ends up being an 
>>> equivalent of = "val%). And it works just as expected. There is nothing to 
>>> change about it.
>>>
>>> However, it just happened to be a query that used to segfault in r507, but 
>>> my guess is that it was related to one of these specificities:
>>>  * this column only has a single value
>>>  * there is no nulls
>>>  * the query returns no results
>>>
>>> To give you a simpler example, the query:
>>>
>>> SELECT single_value_category FROM <partition> WHERE single_value_category 
>>> LIKE 'missing'
>>>
>>> segfaulted as well in r507 for the same reasons. And this exemple doesn't 
>>> involve any fancy de-escaping but share the same specificities (single 
>>> value, no nulls, no results).
>>>
>>> Thanks,
>>>
>>> -----Original Message-----
>>> From: K. John Wu [mailto:[email protected]]
>>> Sent: Thursday, March 29, 2012 12:41 PM
>>> To: Dominique Prunier
>>> Cc: FastBit Users
>>> Subject: Re: [FastBit-users] PATCH: perf boost on top of r501
>>>
>>> Hi, Dominique,
>>>
>>> I see what you are trying to do.  The weird_category only has value
>>> "\"val%\"", therefore, the where clause "weird_category LIKE
>>> '\"val\\%'" should match every row, but "weird_category LIKE 'val\\%'"
>>> should match no row.
>>>
>>> If you can step into category::patternSearch, you will see that
>>> "val\\%" has been stripped to "val%", which will have the same outcome
>>> as you intended, but it stripped away too many back slashes.  You
>>> intend category::patternSearch to see "val\%" to match the literal
>>> percent sign (%), however, because the back slash was stripped twice,
>>> you only got a bare percent sign left, which means it is a wild card
>>> character, not a literal character as you intended.
>>>
>>> My theory is this.  The string "val\\%" becomes "val\%" when it gets
>>> to inside the C code.  The runtime system has stripped away the first
>>> back slash.  The constructor of ibis::qLike take away the second one.
>>>
>>> Since we have gone back and forth many times on this, I will wait for
>>> you confirmation before doing anything about it.
>>>
>>> John
>>>
>>>
>>> On 3/29/12 8:09 AM, Dominique Prunier wrote:
>>>> Hey John,
>>>>
>>>> When i'll have some time, i'll make my test suite dump the queries and 
>>>> expected results so that you try it yourself. It only tests category (and 
>>>> a small bit of long) data types for the things i'm doing but it can be 
>>>> useful.
>>>>
>>>> In the meantime, here is my test partition (see attached) and the query 
>>>> that generated the segfault with r507 was:
>>>>
>>>> SELECT weird_category FROM <partition> WHERE weird_category LIKE '"val\\%' 
>>>> (which is not supposed to return any result)
>>>>
>>>> It might help you understand what could have happened.
>>>>
>>>> Thanks,
>>>>
>>>> -----Original Message-----
>>>> From: K. John Wu [mailto:[email protected]]
>>>> Sent: Thursday, March 29, 2012 10:55 AM
>>>> To: Dominique Prunier
>>>> Cc: FastBit Users
>>>> Subject: Re: [FastBit-users] PATCH: perf boost on top of r501
>>>>
>>>> Good to know.  The problem was then I did not check the array bounds.
>>>>  Odd though, I did not think the values could be out of bounds..
>>>>
>>>> On 3/29/12 7:24 AM, Dominique Prunier wrote:
>>>>> Hi John,
>>>>>
>>>>> I ran the query with r507, and apparently, the problem was there:
>>>>>
>>>>> ==14864== Invalid read of size 8
>>>>> ==14864==    at 0x550067A: ibis::index::sumBins(ibis::array_t<unsigned 
>>>>> int> const&, ibis::bitvector&) const (index.cpp:6371)
>>>>> ==14864==    by 0x576E76D: ibis::category::patternSearch(char const*, 
>>>>> ibis::bitvector&) const (category.cpp:871)
>>>>> ==14864==    by 0x509933C: ibis::part::patternSearch(ibis::qLike const&, 
>>>>> ibis::bitvector&) const (part.cpp:3260)
>>>>> ==14864==    by 0x545FF03: ibis::query::doEvaluate(ibis::qExpr const*, 
>>>>> ibis::bitvector const&, ibis::bitvector&) const (query.cpp:3962)
>>>>> ==14864==    by 0x545B63D: ibis::query::computeHits() (query.cpp:2771)
>>>>> ==14864==    by 0x5452413: ibis::query::evaluate(bool) (query.cpp:847)
>>>>> ==14864==    by 0x587328C: fastbit_build_query (capi.cpp:477)
>>>>> ==14864==    by 0x4030F8: main (main.cpp:38)
>>>>>
>>>>> In r508, the problem is gone !
>>>>>
>>>>> Thanks,
>>>>>
>>>>> -----Original Message-----
>>>>> From: K. John Wu [mailto:[email protected]]
>>>>> Sent: Thursday, March 29, 2012 12:33 AM
>>>>> To: Dominique Prunier
>>>>> Cc: FastBit Users
>>>>> Subject: Re: [FastBit-users] PATCH: perf boost on top of r501
>>>>>
>>>>> Hi, Dominique,
>>>>>
>>>>> The stack trace shows that it is invoking a copy constructor of the
>>>>> ibis::bitvector class when it encountered the seg fault.  Not sure
>>>>> what is the problem here.  I have tried to reproduce the problem by
>>>>> modifying an existing test suite check-maurel.  However, the code
>>>>> seems to work.
>>>>>
>>>>> There is a minor change ibis::index::sumBins to check that the
>>>>> incoming array contains only values less than bits.size() (the number
>>>>> of bitvectors stored in an index object - ibis::direkte is an index
>>>>> object).  This might prevent attempting to out-of-bound accesses.  The
>>>>> change is in SVN Revision 508.
>>>>>
>>>>> If you are able to find more information.  Please let me know.
>>>>>
>>>>> John
>>>>>
>>>>>
>>>>> On 3/28/12 2:07 PM, Dominique Prunier wrote:
>>>>>> Woops, r507 segfaults right away in:
>>>>>>
>>>>>> C  [libfastbit.so.0.0.9+0x800fbb]  
>>>>>> ibis::bitvector::bitvector(ibis::bitvector const&)+0x23
>>>>>> C  [libfastbit.so.0.0.9+0x6d16c1]  
>>>>>> ibis::index::sumBins(ibis::array_t<unsigned> const&, ibis::bitvector&) 
>>>>>> const+0x103
>>>>>> C  [libfastbit.so.0.0.9+0x93f76e]  ibis::category::patternSearch(char 
>>>>>> const*, ibis::bitvector&) const+0x3c8
>>>>>> C  [libfastbit.so.0.0.9+0x26a33d]  ibis::part::patternSearch(ibis::qLike 
>>>>>> const&, ibis::bitvector&) const+0xcf
>>>>>> C  [libfastbit.so.0.0.9+0x630f04]  ibis::query::doEvaluate(ibis::qExpr 
>>>>>> const*, ibis::bitvector const&, ibis::bitvector&) const+0xe1a
>>>>>> C  [libfastbit.so.0.0.9+0x62c63e]  ibis::query::computeHits()+0x356
>>>>>> C  [libfastbit.so.0.0.9+0x623414]  ibis::query::evaluate(bool)+0x4a6
>>>>>> C  [libfastbit.so.0.0.9+0xa4428d]  float+0x3c0
>>>>>> C  [jna1347076628273574295.tmp+0x11b20]  float+0x4c
>>>>>>
>>>>>> I'll try to investigate this latter but the last query of my tests it 
>>>>>> executed was
>>>>>>
>>>>>> SELECT weird_category FROM /tmp/junit8378310225719591578 WHERE 
>>>>>> weird_category LIKE '"val\\%'
>>>>>>
>>>>>> I'll try to investigate this, but it might be related to the fact that 
>>>>>> this query is supposed to return no result.
>>>>>>
>>>>>> Thanks,
>>>>>>
>>>>>> -----Original Message-----
>>>>>> From: [email protected] 
>>>>>> [mailto:[email protected]] On Behalf Of Dominique 
>>>>>> Prunier
>>>>>> Sent: Wednesday, March 28, 2012 4:58 PM
>>>>>> To: K. John Wu
>>>>>> Cc: FastBit Users
>>>>>> Subject: Re: [FastBit-users] PATCH: perf boost on top of r501
>>>>>>
>>>>>> Hey John,
>>>>>>
>>>>>> I'll have a look to r507, probably tomorrow. To limit the risk, i've 
>>>>>> chosen the well tested r506 as my stable version using the 
>>>>>> FASTBIT_EMPTY_STRING_AS_NULL define.
>>>>>>
>>>>>> My problem with null mask is that i write my partitions in pure Java 
>>>>>> code. It is quite straightforward to write data files and -part.txt, but 
>>>>>> writing a NULL mask is something else. Besides, I don't really need a 
>>>>>> difference between NULL and empty anyway, since treating empty strings 
>>>>>> as NULLs is no different than some RDBMS engines that we support (Oracle 
>>>>>> does that for example).
>>>>>>
>>>>>> I have one quick question about category columns. Do they really have a 
>>>>>> separate NULL mask or do they use the bitmap stored at key 0 as their 
>>>>>> NULL mask ? If so, that means that keeping the 
>>>>>> FASTBIT_EMPTY_STRING_AS_NULL would allow me to indirectly build some 
>>>>>> real NULL values which would work with the NOT NULL syntax (which, by 
>>>>>> the way, in SQL is IS NOT NULL/IS NULL, maybe it would be worth changing 
>>>>>> it).
>>>>>>
>>>>>> Thanks,
>>>>>>
>>>>>> -----Original Message-----
>>>>>> From: K. John Wu [mailto:[email protected]]
>>>>>> Sent: Wednesday, March 28, 2012 3:26 PM
>>>>>> To: Dominique Prunier
>>>>>> Cc: FastBit Users
>>>>>> Subject: Re: [FastBit-users] PATCH: perf boost on top of r501
>>>>>>
>>>>>> Hi, Dominique,
>>>>>>
>>>>>> I have added code to accept "colname NOT NULL" in the where clauses.
>>>>>> The new code is in SVN Revision 507.
>>>>>>
>>>>>> The new revision should also consolidate the handling of many
>>>>>> bitvectors in category::patternSearch and address the issue of
>>>>>> possibly missing calls to index::activate (which leads to incorrect
>>>>>> answers).
>>>>>>
>>>>>> You can input null values through tablex::readCSV.  There is an
>>>>>> example in tests/Makefile.am in the way it generates data partition
>>>>>> w7.  The test case 15 of really-small also makes use of the new
>>>>>> expression "NOT NULL".
>>>>>>
>>>>>> Let me know if you spot any problems.
>>>>>>
>>>>>> John
>>>>>>
>>>>>>
>>>>>> On 3/28/12 10:45 AM, Dominique Prunier wrote:
>>>>>>> Hey John,
>>>>>>>
>>>>>>> My guess is that empty strings are used more often that we'd think for 
>>>>>>> the same use case: use them as NULL marker because it is the easiest 
>>>>>>> way to both insert and query (which is exactly what i use them for). 
>>>>>>> Even if it is not an exact synonym of the SQL NULL (especially for 
>>>>>>> propagation), for most use cases, it is close enough. The fact that its 
>>>>>>> key is fixed and well known provides a valid workaround to simulate IS 
>>>>>>> NULL/IS NOT NULL predicates and since it is excluded from most string 
>>>>>>> related predicates (most importantly, a LIKE '%' wont select it), it is 
>>>>>>> a quite easy and intuitive to use.
>>>>>>>
>>>>>>> Besides, the column data file for strings can't represent NULL values 
>>>>>>> so you would have to deal with null masks, which make things 
>>>>>>> significantly more complex (especially, to create a partition from 
>>>>>>> scratch without using the FastBit library) and potentially more 
>>>>>>> resource hungry (have to read/write null mask, ...).
>>>>>>>
>>>>>>> That being said, my only problem with making the distinction between 
>>>>>>> NULL and empty in the dictionary is the current revision's inability to 
>>>>>>> query empty strings and/or NULLs (which is currently worked around by 
>>>>>>> the uint alternative, =0) and the fact that it matches a pattern like 
>>>>>>> '%'. Since there is no guarantee on the empty string key, i don't have 
>>>>>>> any workaround for now.
>>>>>>>
>>>>>>> For the time being, i'll stick with the FASTBIT_EMPTY_STRING_AS_NULL 
>>>>>>> define waiting for the ambiguity to vanish.
>>>>>>>
>>>>>>> Thanks,
>>>>>>>
>>>>>>> -----Original Message-----
>>>>>>> From: K. John Wu [mailto:[email protected]]
>>>>>>> Sent: Wednesday, March 28, 2012 1:22 PM
>>>>>>> To: Dominique Prunier
>>>>>>> Cc: FastBit Users
>>>>>>> Subject: Re: [FastBit-users] PATCH: perf boost on top of r501
>>>>>>>
>>>>>>> The ability to distinguish between empty string and null string can be
>>>>>>> useful.  The ambiguity in the current code is related to some earlier
>>>>>>> design oversight, which we intend to correct.  My hope is that not too
>>>>>>> many people have empty strings that want to do something with, so
>>>>>>> breaking this compatibility is not a big deal.
>>>>>>>
>>>>>>> There are also a problem with the implementation of
>>>>>>> category::patternSearch that neglects to read the bitmaps from index
>>>>>>> files (neglecting to call index::activate).  I am consolidating some
>>>>>>> code to make use of the existing strategies involving summation of a
>>>>>>> large number of bitmaps in ibis::index::sumBits and
>>>>>>> ibis::index::sumBins.  These functions should encapsulate the idea of
>>>>>>> when to decompress bitmaps a lot better than the simple version
>>>>>>> currently in category::patternSearch.
>>>>>>>
>>>>>>> I am doing tests now and will let everyone know when I am ready to
>>>>>>> check the code in.
>>>>>>>
>>>>>>> John
>>>>>>>
>>>>>>>
>>>>>>> On 3/28/12 8:44 AM, Dominique Prunier wrote:
>>>>>>>> Thanks John for your help. It is always very appreciated.
>>>>>>>>
>>>>>>>> With the macro FASTBIT_EMPTY_STRING_AS_NULL enabled, all my test cases 
>>>>>>>> now works. I'll test performance next but it could be a good candidate 
>>>>>>>> for my stable version.
>>>>>>>>
>>>>>>>> About the FASTBIT_EMPTY_STRING_AS_NULL, what do you think would be the 
>>>>>>>> best default ? For my use case, it is obviously to enable it, but for 
>>>>>>>> everybody else i don't know.  My concern is the backward compatibility 
>>>>>>>> here, especially the fact that it influences the index creation, and 
>>>>>>>> not usage. This means that somebody who upgrades won't notice this 
>>>>>>>> change before it regenerates indexes. What's your opinion on this ?
>>>>>>>>
>>>>>>>> Thanks,
>>>>>>>>
>>>>>>>> -----Original Message-----
>>>>>>>> From: K. John Wu [mailto:[email protected]]
>>>>>>>> Sent: Wednesday, March 28, 2012 11:20 AM
>>>>>>>> To: Dominique Prunier
>>>>>>>> Cc: FastBit Users
>>>>>>>> Subject: Re: [FastBit-users] PATCH: perf boost on top of r501
>>>>>>>>
>>>>>>>> Hi, Dominique,
>>>>>>>>
>>>>>>>> Thanks for the suggestions and and test cases.  Just checked in a set
>>>>>>>> of changes as SVN Revision 506.  Here is a bit more explanation.
>>>>>>>>
>>>>>>>> On item 1, I have taken the option you've suggested in the first
>>>>>>>> message, i.e., use the macro FASTBIT_EMPTY_STRING_AS_NULL
>>>>>>>>
>>>>>>>> On item 2, I have restored the escaping of using backslash as you
>>>>>>>> requested.
>>>>>>>>
>>>>>>>> Will go through you tests cases next and see what else I need to 
>>>>>>>> change.
>>>>>>>>
>>>>>>>> John
>>>>>>>>
>>>>>>>>
>>>>>>>> On 3/28/12 8:02 AM, Dominique Prunier wrote:
>>>>>>>>> Hi John,
>>>>>>>>>
>>>>>>>>> Here is two simple test cases for my two issues with r505.
>>>>>>>>>
>>>>>>>>> 1. empty-strings.zip: there is no way to select empty string anymore
>>>>>>>>>
>>>>>>>>> **** FAILED (bad result count) with where clause << a='' >>
>>>>>>>>>
>>>>>>>>> **** FAILED (bad result count) with where clause << a=0 >>
>>>>>>>>>
>>>>>>>>> **** FAILED (hard) with where clause << a LIKE '' >>
>>>>>>>>>
>>>>>>>>> 2. de-escaping.zip: there is no way to select a string with a 
>>>>>>>>> reserved char in it
>>>>>>>>>
>>>>>>>>> **** FAILED (bad result count) with where clause << a='it\'s good' >>
>>>>>>>>>
>>>>>>>>> Warning -- ibis::whereParser encountered syntax error, unexpected 
>>>>>>>>> name string at location a='it's good':1.7
>>>>>>>>> Warning -- query[96w0-3xn8Tg----1]::setWhereClause -- failed to parse 
>>>>>>>>> the WHERE clause "a='it's good'"
>>>>>>>>> Warning -- fastbit_build_query failed to assign conditions (a='it's 
>>>>>>>>> good') to a query
>>>>>>>>> **** FAILED (hard) with where clause << a='it's good' >>
>>>>>>>>>
>>>>>>>>> Warning -- ibis::whereParser encountered syntax error, unexpected 
>>>>>>>>> $undefined at location a=it's good:1.5
>>>>>>>>> Warning -- query[96w0-3xn8Tg----2]::setWhereClause -- failed to parse 
>>>>>>>>> the WHERE clause "a=it's good"
>>>>>>>>> Warning -- fastbit_build_query failed to assign conditions (a=it's 
>>>>>>>>> good) to a query
>>>>>>>>> **** FAILED (hard) with where clause << a=it's good >>
>>>>>>>>>
>>>>>>>>> With the attached patch, it fixes my test cases (except a LIKE '' 
>>>>>>>>> that didn't work before and a='it's good' and a=it's good whieh are 
>>>>>>>>> invalid where clauses).
>>>>>>>>>
>>>>>>>>> Thanks,
>>>>>>>>>
>>>>>>>>> -----Original Message-----
>>>>>>>>> From: [email protected] 
>>>>>>>>> [mailto:[email protected]] On Behalf Of Dominique 
>>>>>>>>> Prunier
>>>>>>>>> Sent: Wednesday, March 28, 2012 10:04 AM
>>>>>>>>> To: K. John Wu
>>>>>>>>> Cc: FastBit Users
>>>>>>>>> Subject: Re: [FastBit-users] PATCH: perf boost on top of r501
>>>>>>>>>
>>>>>>>>> Hey John,
>>>>>>>>>
>>>>>>>>> I'm trying r505 right know, i have two questions/remarks:
>>>>>>>>>
>>>>>>>>>  1. I saw a change about the dictionary now able to accept empty 
>>>>>>>>> strings and treat them as normal strings instead of NULLs. This 
>>>>>>>>> breaks quite a lot of my test cases, specifically those which used to 
>>>>>>>>> test category=0 or !=0 to simulate the IS NULL/IS NOT NULL because 
>>>>>>>>> testing for an empty string doesn't work (='' or LIKE '' used to fail 
>>>>>>>>> or return invalid results). What would be your recommendation for 
>>>>>>>>> that use case ? Could we add a define for those relying on this 
>>>>>>>>> behavior ? Something like:
>>>>>>>>>
>>>>>>>>> -    //if (*str == 0) return 0;
>>>>>>>>> +#ifdef FASTBIT_EMPTY_STRING_AS_NULL
>>>>>>>>> +    if (*str == 0) return 0;
>>>>>>>>> +#endif
>>>>>>>>>
>>>>>>>>>  2. I can't find anywhere the de-escaping patch in r505, am i missing 
>>>>>>>>> something ?
>>>>>>>>>
>>>>>>>>> Thanks,
>>>>>>>>>
>>>>>>>>> -----Original Message-----
>>>>>>>>> From: K. John Wu [mailto:[email protected]]
>>>>>>>>> Sent: Wednesday, March 28, 2012 1:55 AM
>>>>>>>>> To: Dominique Prunier
>>>>>>>>> Cc: FastBit Users
>>>>>>>>> Subject: Re: [FastBit-users] PATCH: perf boost on top of r501
>>>>>>>>>
>>>>>>>>> Hi, Dominique,
>>>>>>>>>
>>>>>>>>> There are some updates to involving merge of dictionaries and to
>>>>>>>>> exercise the operations involving unmatched quotes.  The new code is
>>>>>>>>> SVN R505.
>>>>>>>>>
>>>>>>>>> Please let me know if you have any additional questions.
>>>>>>>>>
>>>>>>>>> John
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> On 3/27/12 1:03 PM, Dominique Prunier wrote:
>>>>>>>>>> Hey John,
>>>>>>>>>>
>>>>>>>>>> There is definitely a need for FastBit escaping. The escaping 
>>>>>>>>>> problem is not at the shell level (though we could have one there) 
>>>>>>>>>> since in pure C/C++ code, there's no shell involved when i'm 
>>>>>>>>>> building a where clause from a string. The problem is at the where 
>>>>>>>>>> clause parsing level (in the lexer to be more precise) to be able to 
>>>>>>>>>> express string literals among other things (and not only metas, it 
>>>>>>>>>> is also white spaces, ...).
>>>>>>>>>> Typically, my test that fails is as simple as calling 
>>>>>>>>>> fastbit_build_query(..., ..., "a='it\\'s good'"). This is expected 
>>>>>>>>>> to create a qString << a = it's good >> but now, it creates a 
>>>>>>>>>> qString << a = it\'s good >> which is wrong. The attached patch 
>>>>>>>>>> restores the descaping, but _not_ the double quote stripping 
>>>>>>>>>> (because it is already handled in the lexer). All my test cases 
>>>>>>>>>> works after applying it on r503.
>>>>>>>>>
>>>>>>>>> The constructors for ibis::qString and ibis::qLike really should not
>>>>>>>>> strip away anything.  In your case, you should be able to do the 
>>>>>>>>> following
>>>>>>>>>
>>>>>>>>> .../tcapi data-dir "a=\"it's good\""
>>>>>>>>>
>>>>>>>>> if you are using fastbit_build_query, you can use the same string
>>>>>>>>> fastbit_build_query(..., ..., "a=\"it's good\"");
>>>>>>>>>
>>>>>>>>> Since FastBit regular expression only support four meta characters ? *
>>>>>>>>> _ %.  There is no need to escape anything.  It is probably cleaner to
>>>>>>>>> not introduce stripping of anything special (except the outer most
>>>>>>>>> quotes, which should be only done once).
>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> About the decompression, thanks for the link, this is very 
>>>>>>>>>> interesting stuff ! But my point here is not about questing the fact 
>>>>>>>>>> the decompression can be better is some case, i was just under the 
>>>>>>>>>> impression that the hit vector given to category::patternSearch was 
>>>>>>>>>> _always_ already decompressed since it is ultimately a bitvector 
>>>>>>>>>> that has been created from scratch for query evaluation (it would 
>>>>>>>>>> need verification though). My guess is that the few percent of 
>>>>>>>>>> performance i'm loosing here are attributable to the check 
>>>>>>>>>> (hits.isCompressed() && hits.bytes()*mult + bv->bytes() > 
>>>>>>>>>> hits.size()), since it gets executed _A LOT_ of times. I'll try to 
>>>>>>>>>> investigate it a little bit further.
>>>>>>>>>
>>>>>>>>> I have rearranged the tests for decompression in layers which
>>>>>>>>> hopefully will eliminate the need to perform more expensive tests in
>>>>>>>>> your case that presumably involve a fairly small number of values.
>>>>>>>>> _______________________________________________
>>>>>>>>> FastBit-users mailing list
>>>>>>>>> [email protected]
>>>>>>>>> https://hpcrdm.lbl.gov/cgi-bin/mailman/listinfo/fastbit-users
>>>>>> _______________________________________________
>>>>>> FastBit-users mailing list
>>>>>> [email protected]
>>>>>> https://hpcrdm.lbl.gov/cgi-bin/mailman/listinfo/fastbit-users
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