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From Yuriy Shuliga <shul...@gmail.com>
Subject Re: Text queries/indexes (GridLuceneIndex, @QueryTextFiled)
Date Thu, 03 Oct 2019 12:44:00 GMT
Denis,

Thank you for your attention to this.
as for now, the https://issues.apache.org/jira/browse/IGNITE-12189 ticket
is still pending review.
Do we have a chance to move it forward somehow?

BR,
Yuriy Shuliha

пн, 30 вер. 2019 о 23:35 Denis Magda <dmagda@apache.org> пише:

> Yuriy,
>
> I've seen you opening a pull-request with the first changes:
> https://issues.apache.org/jira/browse/IGNITE-12189
>
> Alex Scherbakov and Ivan are you the right guys to do the review?
>
> -
> Denis
>
>
> On Fri, Sep 27, 2019 at 8:48 AM Павлухин Иван <vololo100@gmail.com>
wrote:
>
> > Yuriy,
> >
> > Thank you for providing details! Quite interesting.
> >
> > Yes, we already have support of distributed limit and merging sorted
> > subresults for SQL queries. E.g. ReduceIndexSorted and
> > MergeStreamIterator are used for merging sorted streams.
> >
> > Could you please also clarify about score/relevance? Is it provided by
> > Lucene engine for each query result? I am thinking how to do sorted
> > merge properly in this case.
> >
> > ср, 25 сент. 2019 г. в 18:56, Yuriy Shuliga <shuliga@gmail.com>:
> > >
> > > Ivan,
> > >
> > > Thank you for interesting question!
> > >
> > > Text searches (or full text searches) are mostly human-oriented. And
> the
> > > point of user's interest is topmost part of response.
> > > Then user can read it, evaluate and use the given records for further
> > > purposes.
> > >
> > > Particularly in our case, we use Ignite for operations with financial
> > data,
> > > and there lots of text stuff like assets names, fin. instruments,
> > companies
> > > etc.
> > > In order to operate with this quickly and reliably, users used to work
> > with
> > > text search, type-ahead completions, suggestions.
> > >
> > > For this purposes we are indexing particular string data in separate
> > caches.
> > >
> > > Sorting capabilities and response size limitations are very important
> > > there. As our API have to provide most relevant information in view of
> > > limited size.
> > >
> > > Now let me comment some Ignite/Lucene perspective.
> > > Actually Ignite queries and Lucene returns *TopDocs.scoresDocs *already
> > > sorted by *score *(relevance). So most relevant documents are on the
> top.
> > > And currently distributed queries responses from different nodes are
> > merged
> > > into final query cursor queue in arbitrary way.
> > > So in fact we already have the score order ruined here. Also Ignite
> > > requests all possible documents from Lucene that is redundant and not
> > good
> > > for performance.
> > >
> > > I'm implementing *limit* parameter to be part of *TextQuery *and have
> to
> > > notice that we still have to add sorting for text queries processing in
> > > order to have applicable results.
> > >
> > > *Limit* parameter itself should improve the part of issues from above,
> > but
> > > definitely, sorting by document score at least  should be implemented
> > along
> > > with limit.
> > >
> > > This is a pretty short commentary if you still have any questions,
> please
> > > ask, do not hesitate)
> > >
> > > BR,
> > > Yuriy Shuliha
> > >
> > > чт, 19 вер. 2019 о 11:38 Павлухин Иван <vololo100@gmail.com>
пише:
> > >
> > > > Yuriy,
> > > >
> > > > Greatly appreciate your interest.
> > > >
> > > > Could you please elaborate a little bit about sorting? What tasks
> does
> > > > it help to solve and how? It would be great to provide an example.
> > > >
> > > > ср, 18 сент. 2019 г. в 09:39, Alexei Scherbakov <
> > > > alexey.scherbakoff@gmail.com>:
> > > > >
> > > > > Denis,
> > > > >
> > > > > I like the idea of throwing an exception for enabled text queries
> on
> > > > > persistent caches.
> > > > >
> > > > > Also I'm fine with proposed limit for unsorted searches.
> > > > >
> > > > > Yury, please proceed with ticket creation.
> > > > >
> > > > > вт, 17 сент. 2019 г., 22:06 Denis Magda <dmagda@apache.org>:
> > > > >
> > > > > > Igniters,
> > > > > >
> > > > > > I see nothing wrong with Yury's proposal in regards full-text
> > search
> > > > API
> > > > > > evolution as long as Yury is ready to push it forward.
> > > > > >
> > > > > > As for the in-memory mode only, it makes total sense for
> in-memory
> > data
> > > > > > grid deployments when Ignite caches data of an underlying DB
like
> > > > Postgres.
> > > > > > As part of the changes, I would simply throw an exception (by
> > default)
> > > > if
> > > > > > the one attempts to use text indices with the native persistence
> > > > enabled.
> > > > > > If the person is ready to live with that limitation that an
> > explicit
> > > > > > configuration change is needed to come around the exception.
> > > > > >
> > > > > > Thoughts?
> > > > > >
> > > > > >
> > > > > > -
> > > > > > Denis
> > > > > >
> > > > > >
> > > > > > On Tue, Sep 17, 2019 at 7:44 AM Yuriy Shuliga <shuliga@gmail.com
> >
> > > > wrote:
> > > > > >
> > > > > > > Hello to all again,
> > > > > > >
> > > > > > > Thank you for important comments and notes given below!
> > > > > > >
> > > > > > > Let me answer and continue the discussion.
> > > > > > >
> > > > > > > (I) Overall needs in Lucene indexing
> > > > > > >
> > > > > > > Alexei has referenced to
> > > > > > > https://issues.apache.org/jira/browse/IGNITE-5371 where
> > > > > > > absence of index persistence was declared as an obstacle
to
> > further
> > > > > > > development.
> > > > > > >
> > > > > > > a) This ticket is already closed as not valid.b) There
are
> > definite
> > > > needs
> > > > > > > (and in our project as well) in just in-memory indexing
of
> > selected
> > > > data.
> > > > > > > We intend to use search capabilities for fetching limited
> amount
> > of
> > > > > > records
> > > > > > > that should be used in type-ahead search / suggestions.
> > > > > > > Not all of the data will be indexed and the are no need
in
> Lucene
> > > > index
> > > > > > to
> > > > > > > be persistence. Hope this is a wide pattern of text-search
> usage.
> > > > > > >
> > > > > > > (II) Necessary fixes in current implementation.
> > > > > > >
> > > > > > > a) Implementation of correct *limit *(*offset* seems to
be not
> > > > required
> > > > > > in
> > > > > > > text-search tasks for now)
> > > > > > > I have investigated the data flow for distributed text
queries.
> > it
> > > > was
> > > > > > > simple test prefix query, like 'name'*='ene*'*
> > > > > > > For now each server-node returns all response records to
the
> > > > client-node
> > > > > > > and it may contain ~thousands, ~hundred thousands records.
> > > > > > > Event if we need only first 10-100. Again, all the results
are
> > added
> > > > to
> > > > > > > queue in GridCacheQueryFutureAdapter in arbitrary order
by
> pages.
> > > > > > > I did not find here any means to deliver deterministic
result.
> > > > > > > So implementing limit as part of query and
> > (GridCacheQueryRequest)
> > > > will
> > > > > > not
> > > > > > > change the nature of response but will limit load on nodes
and
> > > > > > networking.
> > > > > > >
> > > > > > > Can we consider to open a ticket for this?
> > > > > > >
> > > > > > > (III) Further extension of Lucene API exposition to Ignite
> > > > > > >
> > > > > > > a) Sorting
> > > > > > > The solution for this could be:
> > > > > > > - Make entities comparable
> > > > > > > - Add custom comparator to entity
> > > > > > > - Add annotations to mark sorted fields for Lucene indexing
> > > > > > > - Use comparators when merging responses or reducing to
desired
> > > > limit on
> > > > > > > client node.
> > > > > > > Will require full result set to be loaded into memory.
Though
> > can be
> > > > used
> > > > > > > for relatively small limits.
> > > > > > > BR,
> > > > > > > Yuriy Shuliha
> > > > > > >
> > > > > > > пт, 30 серп. 2019 о 10:37 Alexei Scherbakov <
> > > > > > alexey.scherbakoff@gmail.com>
> > > > > > > пише:
> > > > > > >
> > > > > > > > Yuriy,
> > > > > > > >
> > > > > > > > Note what one of major blockers for text queries is
[1] which
> > makes
> > > > > > > lucene
> > > > > > > > indexes unusable with persistence and main reason
for
> > > > discontinuation.
> > > > > > > > Probably it's should be addressed first to make text
queries
> a
> > > > valid
> > > > > > > > product feature.
> > > > > > > >
> > > > > > > > Distributed sorting and advanved querying is indeed
not a
> > trivial
> > > > task.
> > > > > > > > Some kind of merging must be implemented on query
originating
> > node.
> > > > > > > >
> > > > > > > > [1] https://issues.apache.org/jira/browse/IGNITE-5371
> > > > > > > >
> > > > > > > > чт, 29 авг. 2019 г. в 23:38, Denis Magda <dmagda@apache.org
> >:
> > > > > > > >
> > > > > > > > > Yuriy,
> > > > > > > > >
> > > > > > > > > If you are ready to take over the full-text search
indexes
> > then
> > > > > > please
> > > > > > > go
> > > > > > > > > ahead. The primary reason why the community wants
to
> > discontinue
> > > > them
> > > > > > > > first
> > > > > > > > > (and, probable, resurrect later) are the limitations
listed
> > by
> > > > Andrey
> > > > > > > and
> > > > > > > > > minimal support from the community end.
> > > > > > > > >
> > > > > > > > > -
> > > > > > > > > Denis
> > > > > > > > >
> > > > > > > > >
> > > > > > > > > On Thu, Aug 29, 2019 at 1:29 PM Andrey Mashenkov
<
> > > > > > > > > andrey.mashenkov@gmail.com>
> > > > > > > > > wrote:
> > > > > > > > >
> > > > > > > > > > Hi Yuriy,
> > > > > > > > > >
> > > > > > > > > > Unfortunatelly, there is a plan to discontinue
> TextQueries
> > in
> > > > > > Ignite
> > > > > > > > [1].
> > > > > > > > > > Motivation here is text indexes are not
persistent, not
> > > > > > transactional
> > > > > > > > and
> > > > > > > > > > can't be user together with SQL or inside
SQL.
> > > > > > > > > > and there is a lack of interest from community
side.
> > > > > > > > > > You are weclome to take on these issues
and make
> > TextQueries
> > > > great.
> > > > > > > > > >
> > > > > > > > > > 1,  PageSize can't be used to limit resultset.
> > > > > > > > > > Query results return from data node to client-side
cursor
> > in
> > > > > > > > page-by-page
> > > > > > > > > > manner and
> > > > > > > > > > this parameter is designed control page
size. It is
> > supposed
> > > > query
> > > > > > > > > executes
> > > > > > > > > > lazily on server side and
> > > > > > > > > > it is not excepted full resultset be loaded
to memory on
> > server
> > > > > > side
> > > > > > > at
> > > > > > > > > > once, but by pages.
> > > > > > > > > > Do you mean you found Lucene load entire
resultset into
> > memory
> > > > > > before
> > > > > > > > > first
> > > > > > > > > > page is sent to client?
> > > > > > > > > >
> > > > > > > > > > I'd think a new parameter should be added
to limit
> result.
> > The
> > > > best
> > > > > > > > > > solution is to use query language commands
for this, e.g.
> > > > > > > > "LIMIT/OFFSET"
> > > > > > > > > in
> > > > > > > > > > SQL.
> > > > > > > > > >
> > > > > > > > > > This task doesn't look trivial. Query is
distributed
> > operation
> > > > and
> > > > > > > same
> > > > > > > > > > user query will be executed on data nodes
> > > > > > > > > > and then results from all nodes should be
correcly merged
> > > > before
> > > > > > > being
> > > > > > > > > > returned via client-cursor.
> > > > > > > > > > So, LIMIT should be applied on every node
and then on
> merge
> > > > phase.
> > > > > > > > > >
> > > > > > > > > > Also, this may be non-obviuos, limiting
results make no
> > sence
> > > > > > without
> > > > > > > > > > sorting,
> > > > > > > > > > as there is no guarantee every next query
run will return
> > same
> > > > data
> > > > > > > > > because
> > > > > > > > > > of page reordeing.
> > > > > > > > > > Basically, merge phase receive results from
data nodes
> > > > > > asynchronously
> > > > > > > > and
> > > > > > > > > > messages from different nodes can't be ordered.
> > > > > > > > > >
> > > > > > > > > > 2.
> > > > > > > > > > a. "tokenize" param name (for @QueryTextFiled)
looks more
> > > > verbose,
> > > > > > > > isn't
> > > > > > > > > > it.
> > > > > > > > > > b,c. What about distributed query? How partial
results
> from
> > > > nodes
> > > > > > > will
> > > > > > > > be
> > > > > > > > > > merged?
> > > > > > > > > >  Does Lucene allows to configure comparator
for data
> > sorting?
> > > > > > > > > > What comparator Ignite should choose to
sort result on
> > merge
> > > > phase?
> > > > > > > > > >
> > > > > > > > > > 3. For now Lucene engine is not configurable
at all. E.g.
> > it is
> > > > > > > > > impossible
> > > > > > > > > > to configure Tokenizer.
> > > > > > > > > > I'd think about possible ways to configure
engine at
> first
> > and
> > > > only
> > > > > > > > then
> > > > > > > > > go
> > > > > > > > > > further to discuss\implement complex features,
> > > > > > > > > > that may depends on engine config.
> > > > > > > > > >
> > > > > > > > > >
> > > > > > > > > >
> > > > > > > > > > On Thu, Aug 29, 2019 at 8:17 PM Yuriy Shuliga
<
> > > > shuliga@gmail.com>
> > > > > > > > wrote:
> > > > > > > > > >
> > > > > > > > > > > Dear community,
> > > > > > > > > > >
> > > > > > > > > > > By starting this chain I'd like to
open discussion that
> > would
> > > > > > come
> > > > > > > to
> > > > > > > > > > > contribution results in subj. area.
> > > > > > > > > > >
> > > > > > > > > > > Ignite has indexing capabilities, backed
up by
> different
> > > > > > > mechanisms,
> > > > > > > > > > > including Lucene.
> > > > > > > > > > >
> > > > > > > > > > > Currently, Lucene 7.5.0 is used (past
year release).
> > > > > > > > > > > This is a wide spread and mature technology
that covers
> > text
> > > > > > search
> > > > > > > > > area
> > > > > > > > > > > and beyond (e.g. spacial data indexing).
> > > > > > > > > > >
> > > > > > > > > > > My goal is to *expose more Lucene functionality
to
> Ignite
> > > > > > indexing
> > > > > > > > and
> > > > > > > > > > > query mechanisms for text data*.
> > > > > > > > > > >
> > > > > > > > > > > It's quite simple request at current
stage. It is
> coming
> > > > from our
> > > > > > > > > > project's
> > > > > > > > > > > needs, but i believe, will be useful
for a lot more
> > people.
> > > > > > > > > > > Let's walk through and vote or discuss
about Jira
> > tickets for
> > > > > > them.
> > > > > > > > > > >
> > > > > > > > > > > 1.[trivial] Use  dataQuery.getPageSize()
 to limit
> search
> > > > > > response
> > > > > > > > > items
> > > > > > > > > > > inside GridLuceneIndex.query(). Currently
it is calling
> > > > > > > > > > > IndexSearcher.search(query, *Integer.MAX_VALUE*)
- so
> > > > basically
> > > > > > all
> > > > > > > > > > scored
> > > > > > > > > > > matches will me returned, what we do
not need in most
> > cases.
> > > > > > > > > > >
> > > > > > > > > > > 2.[simple] Add sorting.  Then more
capable search call
> > can be
> > > > > > > > > > > executed: *IndexSearcher.search(query,
count,
> > > > > > > > > > > sort) *
> > > > > > > > > > > Implementation steps:
> > > > > > > > > > > a) Introduce boolean *sortField* parameter
in
> > > > *@QueryTextFiled *
> > > > > > > > > > > annotation. If
> > > > > > > > > > > *true *the filed will be indexed but
not tokenized.
> > Number
> > > > types
> > > > > > > are
> > > > > > > > > > > preferred here.
> > > > > > > > > > > b) Add *sort* collection to *TextQuery*
constructor. It
> > > > should
> > > > > > > define
> > > > > > > > > > > desired sort fields used for querying.
> > > > > > > > > > > c) Implement Lucene sort usage in
> > GridLuceneIndex.query().
> > > > > > > > > > >
> > > > > > > > > > > 3.[moderate] Build complex queries
with *TextQuery*,
> > > > including
> > > > > > > > > > > terms/queries boosting.
> > > > > > > > > > > *This section for voting only, as requires
more
> detailed
> > > > work.
> > > > > > > Should
> > > > > > > > > be
> > > > > > > > > > > extended if community is interested
in it.*
> > > > > > > > > > >
> > > > > > > > > > > Looking forward to your comments!
> > > > > > > > > > >
> > > > > > > > > > > BR,
> > > > > > > > > > > Yuriy Shuliha
> > > > > > > > > > >
> > > > > > > > > >
> > > > > > > > > >
> > > > > > > > > > --
> > > > > > > > > > Best regards,
> > > > > > > > > > Andrey V. Mashenkov
> > > > > > > > > >
> > > > > > > > >
> > > > > > > >
> > > > > > > >
> > > > > > > > --
> > > > > > > >
> > > > > > > > Best regards,
> > > > > > > > Alexei Scherbakov
> > > > > > > >
> > > > > > >
> > > > > >
> > > >
> > > >
> > > >
> > > > --
> > > > Best regards,
> > > > Ivan Pavlukhin
> > > >
> >
> >
> >
> > --
> > Best regards,
> > Ivan Pavlukhin
> >
>

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