subject:"Re\: Transformers in SCAN queries"

Re: Transformers in SCAN queries

2016-02-11 Thread Dmitriy Setrakyan

t; believe all the transformations must happen at SQL level here.
> > > > > > >
> > > > > > > Sergi
> > > > > > >
> > > > > > >
> > > > > > >
> > > > > > > 2016-02-04 20:10 GMT+03:00 Andrey Gura <ag...@gridgain.com>:
> > > > > > >
> > > > > > > > SqlQuery, TextQuery and SpiQuery are similar to ScanQuery
> > because
> > > > all
> > > > > > of
> > > > > > > > them also defined as Query<Cache.Entry<>>.
> > > > > > > >
> > > > > > > > It can be usefull to have one query SqlQuery that can return
> > > > > different
> > > > > > > > result that will be produced from cache entry by transformer.
> > > > > > > >
> > > > > > > > Actually only SqlFieldsQuery has different definition. So
> > > > > transformers
> > > > > > > can
> > > > > > > > be applied to any type of query (including SqlFieldsQuery, I
> > > > > believe).
> > > > > > > >
> > > > > > > > On Thu, Feb 4, 2016 at 7:42 PM, Sergi Vladykin <
> > > > > > sergi.vlady...@gmail.com
> > > > > > > >
> > > > > > > > wrote:
> > > > > > > >
> > > > > > > > > I don't like the idea of having additional method
> > > *query(Query
> > > > > > qry,
> > > > > > > > > Transformer<E, R> transfomer); *because I don't see how
> these
> > > > > > > > transformers
> > > > > > > > > will work for example with SQL, but this API makes you
> think
> > > that
> > > > > > > > > transformers are supported for all the query types.
> > > > > > > > >
> > > > > > > > > Sergi
> > > > > > > > >
> > > > > > > > > 2016-02-04 16:46 GMT+03:00 Andrey Gura <ag...@gridgain.com
> >:
> > > > > > > > >
> > > > > > > > > > Val,
> > > > > > > > > >
> > > > > > > > > > can we introduce new method into IgnteCache API?
> > > > > > > > > >
> > > > > > > > > > Now we have method: public  QueryCursor
> > query(Query
> > > > > qry);
> > > > > > > > > >
> > > > > > > > > > New method will be something like this: 
> QueryCursor
> > > > > > > > query(Query
> > > > > > > > > > qry, Transformer<E, R> transfomer);
> > > > > > > > > >
> > > > > > > > > > It allows provide transformers for all query types and
> > > chnages
> > > > > will
> > > > > > > be
> > > > > > > > > > related only with query cursor functionality.
> > > > > > > > > >
> > > > > > > > > > Will it work?
> > > > > > > > > >
> > > > > > > > > > On Thu, Feb 4, 2016 at 11:13 AM, Andrey Kornev <
> > > > > > > > andrewkor...@hotmail.com
> > > > > > > > > >
> > > > > > > > > > wrote:
> > > > > > > > > >
> > > > > > > > > > > Another perhaps bigger problem with running queries
> > > > (including
> > > > > > scan
> > > > > > > > > > > queries) using closures was discussed at length on the
> > @dev
> > > > not
> > > > > > so
> > > > > > > > long
> > > > > > > > > > > ago. It has to do with partitions migration due to
> > cluster
> > > > > > topology
> > > > > > > > > > changes
> > > > > > > > > > > which may result in the query returning incomplete
> > result.
> > > > And
> > > > > > > while
> > > > > > > > it
> > > > > > > > > > is
> > > > > > > > > > > possible to so

Re: Transformers in SCAN queries

2016-02-10 Thread Dmitriy Setrakyan

thod will be something like this:  QueryCursor
> > > > > query(Query
> > > > > > > qry, Transformer<E, R> transfomer);
> > > > > > >
> > > > > > > It allows provide transformers for all query types and chnages
> > will
> > > > be
> > > > > > > related only with query cursor functionality.
> > > > > > >
> > > > > > > Will it work?
> > > > > > >
> > > > > > > On Thu, Feb 4, 2016 at 11:13 AM, Andrey Kornev <
> > > > > andrewkor...@hotmail.com
> > > > > > >
> > > > > > > wrote:
> > > > > > >
> > > > > > > > Another perhaps bigger problem with running queries
> (including
> > > scan
> > > > > > > > queries) using closures was discussed at length on the @dev
> not
> > > so
> > > > > long
> > > > > > > > ago. It has to do with partitions migration due to cluster
> > > topology
> > > > > > > changes
> > > > > > > > which may result in the query returning incomplete result.
> And
> > > > while
> > > > > it
> > > > > > > is
> > > > > > > > possible to solve this problem for the scan queries by using
> > some
> > > > > > clever
> > > > > > > > tricks, all bets are off with the SQL queries.Andrey
> > > > > > > > _
> > > > > > > > From: Valentin Kulichenko <valentin.kuliche...@gmail.com>
> > > > > > > > Sent: Thursday, February 4, 2016 6:29 AM
> > > > > > > > Subject: Re: Transformers in SCAN queries
> > > > > > > > To:  <dev@ignite.apache.org>
> > > > > > > >
> > > > > > > >
> > > > > > > >Dmitry,
> > > > > > > >
> > > > > > > >  The main difference in my view is that you lose pagination
> > when
> > > > > > sending
> > > > > > > >  results from servers to client. What if one wants to iterate
> > > > through
> > > > > > all
> > > > > > > >  entries in cache?
> > > > > > > >
> > > > > > > >  On Wed, Feb 3, 2016 at 9:47 PM, Dmitriy Setrakyan <
> > > > > > > dsetrak...@apache.org>
> > > > > > > >  wrote:
> > > > > > > >
> > > > > > > >  > Valentin,
> > > > > > > >  >
> > > > > > > >  > Wouldn’t the same effect be achieved by broadcasting a
> > closure
> > > > to
> > > > > > the
> > > > > > > >  > cluster and executing scan-query on every node locally?
> > > > > > > >  >
> > > > > > > >  > D.
> > > > > > > >  >
> > > > > > > >  > On Wed, Feb 3, 2016 at 9:17 PM, Valentin Kulichenko <
> > > > > > > >  > valentin.kuliche...@gmail.com> wrote:
> > > > > > > >  >
> > > > > > > >  > > Igniters,
> > > > > > > >  > >
> > > > > > > >  > > I keep getting requests from our users to add optional
> > > > > > transformers
> > > > > > > to
> > > > > > > >  > SCAN
> > > > > > > >  > > queries. This will allow to iterate through cache, but
> do
> > > not
> > > > > > > transfer
> > > > > > > >  > > whole key-value pairs across networks (e.g., get only
> > keys).
> > > > The
> > > > > > > > feature
> > > > > > > >  > > looks useful and I created a ticket [1].
> > > > > > > >  > >
> > > > > > > >  > > I am struggling with the design now. The problem is
> that I
> > > > > wanted
> > > > > > to
> > > > > > > >  > extend
> > > > > > > >  > > existing ScanQuery object for this, but this seems to be
> > > > > > impossible
> > > > > > > >  > because
> > > > > > > >  > > it already extends Query<Cache.Entry<K, V>> and thus can
> > > > iterate
> > > > > > > only
> > > > > > > >  > > through entries.
> > > > > > > >  > >
> > > > > > > >  > > The only option I see now is to create a separate query
> > > type,
> > > > > > > > copy-paste
> > > > > > > >  > > everything from ScanQuery and add *mandatory*
> transformer.
> > > > > > Something
> > > > > > > > like
> > > > > > > >  > > this:
> > > > > > > >  > >
> > > > > > > >  > > ScanTransformQuery<K, V, R> extends Query {
> > > > > > > >  > > IgniteBiPredicate<K, V> filter;
> > > > > > > >  > > IgniteClosure<Cache.Entry<K, V>, R> transformer;
> > > > > > > >  > > int part;
> > > > > > > >  > > ...
> > > > > > > >  > > }
> > > > > > > >  > >
> > > > > > > >  > > Thoughts? Does anyone has other ideas?
> > > > > > > >  > >
> > > > > > > >  > > [1]
> https://issues.apache.org/jira/browse/IGNITE-2546
> > > > > > > >  > >
> > > > > > > >  > > -Val
> > > > > > > >  > >
> > > > > > > >  >
> > > > > > > >
> > > > > > > >
> > > > > > > >
> > > > > > > >
> > > > > > > >
> > > > > > >
> > > > > > >
> > > > > > >
> > > > > > > --
> > > > > > > Andrey Gura
> > > > > > > GridGain Systems, Inc.
> > > > > > > www.gridgain.com
> > > > > > >
> > > > > >
> > > > >
> > > > >
> > > > >
> > > > > --
> > > > > Andrey Gura
> > > > > GridGain Systems, Inc.
> > > > > www.gridgain.com
> > > > >
> > > >
> > >
> > >
> > >
> > > --
> > > Andrey Gura
> > > GridGain Systems, Inc.
> > > www.gridgain.com
> > >
> >
>
>
>
> --
> Andrey Gura
> GridGain Systems, Inc.
> www.gridgain.com
>

Re: Transformers in SCAN queries

2016-02-10 Thread Valentin Kulichenko

; transformers
> > > > > > > will work for example with SQL, but this API makes you think
> that
> > > > > > > transformers are supported for all the query types.
> > > > > > >
> > > > > > > Sergi
> > > > > > >
> > > > > > > 2016-02-04 16:46 GMT+03:00 Andrey Gura <ag...@gridgain.com>:
> > > > > > >
> > > > > > > > Val,
> > > > > > > >
> > > > > > > > can we introduce new method into IgnteCache API?
> > > > > > > >
> > > > > > > > Now we have method: public  QueryCursor query(Query
> > > qry);
> > > > > > > >
> > > > > > > > New method will be something like this:  QueryCursor
> > > > > > query(Query
> > > > > > > > qry, Transformer<E, R> transfomer);
> > > > > > > >
> > > > > > > > It allows provide transformers for all query types and
> chnages
> > > will
> > > > > be
> > > > > > > > related only with query cursor functionality.
> > > > > > > >
> > > > > > > > Will it work?
> > > > > > > >
> > > > > > > > On Thu, Feb 4, 2016 at 11:13 AM, Andrey Kornev <
> > > > > > andrewkor...@hotmail.com
> > > > > > > >
> > > > > > > > wrote:
> > > > > > > >
> > > > > > > > > Another perhaps bigger problem with running queries
> > (including
> > > > scan
> > > > > > > > > queries) using closures was discussed at length on the @dev
> > not
> > > > so
> > > > > > long
> > > > > > > > > ago. It has to do with partitions migration due to cluster
> > > > topology
> > > > > > > > changes
> > > > > > > > > which may result in the query returning incomplete result.
> > And
> > > > > while
> > > > > > it
> > > > > > > > is
> > > > > > > > > possible to solve this problem for the scan queries by
> using
> > > some
> > > > > > > clever
> > > > > > > > > tricks, all bets are off with the SQL queries.Andrey
> > > > > > > > > _
> > > > > > > > > From: Valentin Kulichenko <valentin.kuliche...@gmail.com>
> > > > > > > > > Sent: Thursday, February 4, 2016 6:29 AM
> > > > > > > > > Subject: Re: Transformers in SCAN queries
> > > > > > > > > To:  <dev@ignite.apache.org>
> > > > > > > > >
> > > > > > > > >
> > > > > > > > >Dmitry,
> > > > > > > > >
> > > > > > > > >  The main difference in my view is that you lose pagination
> > > when
> > > > > > > sending
> > > > > > > > >  results from servers to client. What if one wants to
> iterate
> > > > > through
> > > > > > > all
> > > > > > > > >  entries in cache?
> > > > > > > > >
> > > > > > > > >  On Wed, Feb 3, 2016 at 9:47 PM, Dmitriy Setrakyan <
> > > > > > > > dsetrak...@apache.org>
> > > > > > > > >  wrote:
> > > > > > > > >
> > > > > > > > >  > Valentin,
> > > > > > > > >  >
> > > > > > > > >  > Wouldn’t the same effect be achieved by broadcasting a
> > > closure
> > > > > to
> > > > > > > the
> > > > > > > > >  > cluster and executing scan-query on every node locally?
> > > > > > > > >  >
> > > > > > > > >  > D.
> > > > > > > > >  >
> > > > > > > > >  > On Wed, Feb 3, 2016 at 9:17 PM, Valentin Kulichenko <
> > > > > > > > >  > valentin.kuliche...@gmail.com> wrote:
> > > > > > > > >  >
> > > > > > > > >  > > Igniters,
> > > > > > > > >  > >
> > > > > > > > >  > > I keep getting requests from our users to add optional
> > > > > > > transformers
> > > > > > > > to
> > > > > > > > >  > SCAN
> > > > > > > > >  > > queries. This will allow to iterate through cache, but
> > do
> > > > not
> > > > > > > > transfer
> > > > > > > > >  > > whole key-value pairs across networks (e.g., get only
> > > keys).
> > > > > The
> > > > > > > > > feature
> > > > > > > > >  > > looks useful and I created a ticket [1].
> > > > > > > > >  > >
> > > > > > > > >  > > I am struggling with the design now. The problem is
> > that I
> > > > > > wanted
> > > > > > > to
> > > > > > > > >  > extend
> > > > > > > > >  > > existing ScanQuery object for this, but this seems to
> be
> > > > > > > impossible
> > > > > > > > >  > because
> > > > > > > > >  > > it already extends Query<Cache.Entry<K, V>> and thus
> can
> > > > > iterate
> > > > > > > > only
> > > > > > > > >  > > through entries.
> > > > > > > > >  > >
> > > > > > > > >  > > The only option I see now is to create a separate
> query
> > > > type,
> > > > > > > > > copy-paste
> > > > > > > > >  > > everything from ScanQuery and add *mandatory*
> > transformer.
> > > > > > > Something
> > > > > > > > > like
> > > > > > > > >  > > this:
> > > > > > > > >  > >
> > > > > > > > >  > > ScanTransformQuery<K, V, R> extends Query {
> > > > > > > > >  > > IgniteBiPredicate<K, V> filter;
> > > > > > > > >  > > IgniteClosure<Cache.Entry<K, V>, R> transformer;
> > > > > > > > >  > > int part;
> > > > > > > > >  > > ...
> > > > > > > > >  > > }
> > > > > > > > >  > >
> > > > > > > > >  > > Thoughts? Does anyone has other ideas?
> > > > > > > > >  > >
> > > > > > > > >  > > [1]
> > https://issues.apache.org/jira/browse/IGNITE-2546
> > > > > > > > >  > >
> > > > > > > > >  > > -Val
> > > > > > > > >  > >
> > > > > > > > >  >
> > > > > > > > >
> > > > > > > > >
> > > > > > > > >
> > > > > > > > >
> > > > > > > > >
> > > > > > > >
> > > > > > > >
> > > > > > > >
> > > > > > > > --
> > > > > > > > Andrey Gura
> > > > > > > > GridGain Systems, Inc.
> > > > > > > > www.gridgain.com
> > > > > > > >
> > > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > > > --
> > > > > > Andrey Gura
> > > > > > GridGain Systems, Inc.
> > > > > > www.gridgain.com
> > > > > >
> > > > >
> > > >
> > > >
> > > >
> > > > --
> > > > Andrey Gura
> > > > GridGain Systems, Inc.
> > > > www.gridgain.com
> > > >
> > >
> >
> >
> >
> > --
> > Andrey Gura
> > GridGain Systems, Inc.
> > www.gridgain.com
> >
>

Re: Transformers in SCAN queries

2016-02-04 Thread Andrey Gura

Val,

>From my point of view, special query class that allows transforming is
confusing. Two points about it:

1. ScanTransformQuery will duplicate ScanQuery code with all drawbacks that
we have. Moreover, any fix for ScanQuery should be repeated for
ScanTransformQuery. It will lead to bugs. DRY.

2. If some users want to do transformations for SqlQuery we will introduce
SqlTransformQuery. Right? At this point see previous item.

Transformation logic is some kind of strategy. IMHO, the most convenient
API should get transformation logic as some function provided by user.

On Thu, Feb 4, 2016 at 11:05 PM, Valentin Kulichenko <
valentin.kuliche...@gmail.com> wrote:

> Agree with Sergi. Mixing SQL with Java code transformers is confusing. In
> rare case when it's really required, user can implement a custom function.
>
> I copy-pasted the API to the ticket [1]. Please provide any additional
> comments there.
>
> [1] https://issues.apache.org/jira/browse/IGNITE-2546
>
> -Val
>
> On Thu, Feb 4, 2016 at 10:08 AM, Andrey Gura <ag...@gridgain.com> wrote:
>
> > Sergi,
> >
> >
> > > What you are going to transform remotely here?
> >
> >
> > I'm not going. I believe :)
> >
> > Just hypothetical use case: You have one SqlFieldsQuery but different
> > requirements for returned values. For one case you have to return some
> > string fields as is and for another case you have to trim string to 32
> > characters. Of course you still can trim strings locally but transformers
> > allow you do it remotely.
> >
> > Anyway, this solution can be usefull for rest query types.
> >
> > On Thu, Feb 4, 2016 at 8:54 PM, Sergi Vladykin <sergi.vlady...@gmail.com
> >
> > wrote:
> >
> > > The whole point of Transformer is to do remote transform, how will this
> > > work with SqlFieldsQuery? What you are going to transform remotely
> here?
> > I
> > > believe all the transformations must happen at SQL level here.
> > >
> > > Sergi
> > >
> > >
> > >
> > > 2016-02-04 20:10 GMT+03:00 Andrey Gura <ag...@gridgain.com>:
> > >
> > > > SqlQuery, TextQuery and SpiQuery are similar to ScanQuery because all
> > of
> > > > them also defined as Query<Cache.Entry<>>.
> > > >
> > > > It can be usefull to have one query SqlQuery that can return
> different
> > > > result that will be produced from cache entry by transformer.
> > > >
> > > > Actually only SqlFieldsQuery has different definition. So
> transformers
> > > can
> > > > be applied to any type of query (including SqlFieldsQuery, I
> believe).
> > > >
> > > > On Thu, Feb 4, 2016 at 7:42 PM, Sergi Vladykin <
> > sergi.vlady...@gmail.com
> > > >
> > > > wrote:
> > > >
> > > > > I don't like the idea of having additional method *query(Query
> > qry,
> > > > > Transformer<E, R> transfomer); *because I don't see how these
> > > > transformers
> > > > > will work for example with SQL, but this API makes you think that
> > > > > transformers are supported for all the query types.
> > > > >
> > > > > Sergi
> > > > >
> > > > > 2016-02-04 16:46 GMT+03:00 Andrey Gura <ag...@gridgain.com>:
> > > > >
> > > > > > Val,
> > > > > >
> > > > > > can we introduce new method into IgnteCache API?
> > > > > >
> > > > > > Now we have method: public  QueryCursor query(Query
> qry);
> > > > > >
> > > > > > New method will be something like this:  QueryCursor
> > > > query(Query
> > > > > > qry, Transformer<E, R> transfomer);
> > > > > >
> > > > > > It allows provide transformers for all query types and chnages
> will
> > > be
> > > > > > related only with query cursor functionality.
> > > > > >
> > > > > > Will it work?
> > > > > >
> > > > > > On Thu, Feb 4, 2016 at 11:13 AM, Andrey Kornev <
> > > > andrewkor...@hotmail.com
> > > > > >
> > > > > > wrote:
> > > > > >
> > > > > > > Another perhaps bigger problem with running queries (including
> > scan
> > > > > > > queries) using closures was discussed at length on the @dev not
> > so
> > > > long
> >

Re: Transformers in SCAN queries

2016-02-04 Thread Andrey Gura

SqlQuery, TextQuery and SpiQuery are similar to ScanQuery because all of
them also defined as Query<Cache.Entry<>>.

It can be usefull to have one query SqlQuery that can return different
result that will be produced from cache entry by transformer.

Actually only SqlFieldsQuery has different definition. So transformers can
be applied to any type of query (including SqlFieldsQuery, I believe).

On Thu, Feb 4, 2016 at 7:42 PM, Sergi Vladykin <sergi.vlady...@gmail.com>
wrote:

> I don't like the idea of having additional method *query(Query qry,
> Transformer<E, R> transfomer); *because I don't see how these transformers
> will work for example with SQL, but this API makes you think that
> transformers are supported for all the query types.
>
> Sergi
>
> 2016-02-04 16:46 GMT+03:00 Andrey Gura <ag...@gridgain.com>:
>
> > Val,
> >
> > can we introduce new method into IgnteCache API?
> >
> > Now we have method: public  QueryCursor query(Query qry);
> >
> > New method will be something like this:  QueryCursor query(Query
> > qry, Transformer<E, R> transfomer);
> >
> > It allows provide transformers for all query types and chnages will be
> > related only with query cursor functionality.
> >
> > Will it work?
> >
> > On Thu, Feb 4, 2016 at 11:13 AM, Andrey Kornev <andrewkor...@hotmail.com
> >
> > wrote:
> >
> > > Another perhaps bigger problem with running queries (including scan
> > > queries) using closures was discussed at length on the @dev not so long
> > > ago. It has to do with partitions migration due to cluster topology
> > changes
> > > which may result in the query returning incomplete result. And while it
> > is
> > > possible to solve this problem for the scan queries by using some
> clever
> > > tricks, all bets are off with the SQL queries.Andrey
> > > _
> > > From: Valentin Kulichenko <valentin.kuliche...@gmail.com>
> > > Sent: Thursday, February 4, 2016 6:29 AM
> > > Subject: Re: Transformers in SCAN queries
> > > To:  <dev@ignite.apache.org>
> > >
> > >
> > >Dmitry,
> > >
> > >  The main difference in my view is that you lose pagination when
> sending
> > >  results from servers to client. What if one wants to iterate through
> all
> > >  entries in cache?
> > >
> > >  On Wed, Feb 3, 2016 at 9:47 PM, Dmitriy Setrakyan <
> > dsetrak...@apache.org>
> > >  wrote:
> > >
> > >  > Valentin,
> > >  >
> > >  > Wouldn’t the same effect be achieved by broadcasting a closure to
> the
> > >  > cluster and executing scan-query on every node locally?
> > >  >
> > >  > D.
> > >  >
> > >  > On Wed, Feb 3, 2016 at 9:17 PM, Valentin Kulichenko <
> > >  > valentin.kuliche...@gmail.com> wrote:
> > >  >
> > >  > > Igniters,
> > >  > >
> > >  > > I keep getting requests from our users to add optional
> transformers
> > to
> > >  > SCAN
> > >  > > queries. This will allow to iterate through cache, but do not
> > transfer
> > >  > > whole key-value pairs across networks (e.g., get only keys). The
> > > feature
> > >  > > looks useful and I created a ticket [1].
> > >  > >
> > >  > > I am struggling with the design now. The problem is that I wanted
> to
> > >  > extend
> > >  > > existing ScanQuery object for this, but this seems to be
> impossible
> > >  > because
> > >  > > it already extends Query<Cache.Entry<K, V>> and thus can iterate
> > only
> > >  > > through entries.
> > >  > >
> > >  > > The only option I see now is to create a separate query type,
> > > copy-paste
> > >  > > everything from ScanQuery and add *mandatory* transformer.
> Something
> > > like
> > >  > > this:
> > >  > >
> > >  > > ScanTransformQuery<K, V, R> extends Query {
> > >  > > IgniteBiPredicate<K, V> filter;
> > >  > > IgniteClosure<Cache.Entry<K, V>, R> transformer;
> > >  > > int part;
> > >  > > ...
> > >  > > }
> > >  > >
> > >  > > Thoughts? Does anyone has other ideas?
> > >  > >
> > >  > > [1]https://issues.apache.org/jira/browse/IGNITE-2546
> > >  > >
> > >  > > -Val
> > >  > >
> > >  >
> > >
> > >
> > >
> > >
> > >
> >
> >
> >
> > --
> > Andrey Gura
> > GridGain Systems, Inc.
> > www.gridgain.com
> >
>



-- 
Andrey Gura
GridGain Systems, Inc.
www.gridgain.com

Re: Transformers in SCAN queries

2016-02-04 Thread Sergi Vladykin

I don't like the idea of having additional method *query(Query qry,
Transformer<E, R> transfomer); *because I don't see how these transformers
will work for example with SQL, but this API makes you think that
transformers are supported for all the query types.

Sergi

2016-02-04 16:46 GMT+03:00 Andrey Gura <ag...@gridgain.com>:

> Val,
>
> can we introduce new method into IgnteCache API?
>
> Now we have method: public  QueryCursor query(Query qry);
>
> New method will be something like this:  QueryCursor query(Query
> qry, Transformer<E, R> transfomer);
>
> It allows provide transformers for all query types and chnages will be
> related only with query cursor functionality.
>
> Will it work?
>
> On Thu, Feb 4, 2016 at 11:13 AM, Andrey Kornev <andrewkor...@hotmail.com>
> wrote:
>
> > Another perhaps bigger problem with running queries (including scan
> > queries) using closures was discussed at length on the @dev not so long
> > ago. It has to do with partitions migration due to cluster topology
> changes
> > which may result in the query returning incomplete result. And while it
> is
> > possible to solve this problem for the scan queries by using some clever
> > tricks, all bets are off with the SQL queries.Andrey
> > _____
> > From: Valentin Kulichenko <valentin.kuliche...@gmail.com>
> > Sent: Thursday, February 4, 2016 6:29 AM
> > Subject: Re: Transformers in SCAN queries
> > To:  <dev@ignite.apache.org>
> >
> >
> >Dmitry,
> >
> >  The main difference in my view is that you lose pagination when sending
> >  results from servers to client. What if one wants to iterate through all
> >  entries in cache?
> >
> >  On Wed, Feb 3, 2016 at 9:47 PM, Dmitriy Setrakyan <
> dsetrak...@apache.org>
> >  wrote:
> >
> >  > Valentin,
> >  >
> >  > Wouldn’t the same effect be achieved by broadcasting a closure to the
> >  > cluster and executing scan-query on every node locally?
> >  >
> >  > D.
> >  >
> >  > On Wed, Feb 3, 2016 at 9:17 PM, Valentin Kulichenko <
> >  > valentin.kuliche...@gmail.com> wrote:
> >  >
> >  > > Igniters,
> >  > >
> >  > > I keep getting requests from our users to add optional transformers
> to
> >  > SCAN
> >  > > queries. This will allow to iterate through cache, but do not
> transfer
> >  > > whole key-value pairs across networks (e.g., get only keys). The
> > feature
> >  > > looks useful and I created a ticket [1].
> >  > >
> >  > > I am struggling with the design now. The problem is that I wanted to
> >  > extend
> >  > > existing ScanQuery object for this, but this seems to be impossible
> >  > because
> >  > > it already extends Query<Cache.Entry<K, V>> and thus can iterate
> only
> >  > > through entries.
> >  > >
> >  > > The only option I see now is to create a separate query type,
> > copy-paste
> >  > > everything from ScanQuery and add *mandatory* transformer. Something
> > like
> >  > > this:
> >  > >
> >  > > ScanTransformQuery<K, V, R> extends Query {
> >  > > IgniteBiPredicate<K, V> filter;
> >  > > IgniteClosure<Cache.Entry<K, V>, R> transformer;
> >  > > int part;
> >  > > ...
> >  > > }
> >  > >
> >  > > Thoughts? Does anyone has other ideas?
> >  > >
> >  > > [1]https://issues.apache.org/jira/browse/IGNITE-2546
> >  > >
> >  > > -Val
> >  > >
> >  >
> >
> >
> >
> >
> >
>
>
>
> --
> Andrey Gura
> GridGain Systems, Inc.
> www.gridgain.com
>

Re: Transformers in SCAN queries

2016-02-04 Thread Sergi Vladykin

The whole point of Transformer is to do remote transform, how will this
work with SqlFieldsQuery? What you are going to transform remotely here? I
believe all the transformations must happen at SQL level here.

Sergi



2016-02-04 20:10 GMT+03:00 Andrey Gura <ag...@gridgain.com>:

> SqlQuery, TextQuery and SpiQuery are similar to ScanQuery because all of
> them also defined as Query<Cache.Entry<>>.
>
> It can be usefull to have one query SqlQuery that can return different
> result that will be produced from cache entry by transformer.
>
> Actually only SqlFieldsQuery has different definition. So transformers can
> be applied to any type of query (including SqlFieldsQuery, I believe).
>
> On Thu, Feb 4, 2016 at 7:42 PM, Sergi Vladykin <sergi.vlady...@gmail.com>
> wrote:
>
> > I don't like the idea of having additional method *query(Query qry,
> > Transformer<E, R> transfomer); *because I don't see how these
> transformers
> > will work for example with SQL, but this API makes you think that
> > transformers are supported for all the query types.
> >
> > Sergi
> >
> > 2016-02-04 16:46 GMT+03:00 Andrey Gura <ag...@gridgain.com>:
> >
> > > Val,
> > >
> > > can we introduce new method into IgnteCache API?
> > >
> > > Now we have method: public  QueryCursor query(Query qry);
> > >
> > > New method will be something like this:  QueryCursor
> query(Query
> > > qry, Transformer<E, R> transfomer);
> > >
> > > It allows provide transformers for all query types and chnages will be
> > > related only with query cursor functionality.
> > >
> > > Will it work?
> > >
> > > On Thu, Feb 4, 2016 at 11:13 AM, Andrey Kornev <
> andrewkor...@hotmail.com
> > >
> > > wrote:
> > >
> > > > Another perhaps bigger problem with running queries (including scan
> > > > queries) using closures was discussed at length on the @dev not so
> long
> > > > ago. It has to do with partitions migration due to cluster topology
> > > changes
> > > > which may result in the query returning incomplete result. And while
> it
> > > is
> > > > possible to solve this problem for the scan queries by using some
> > clever
> > > > tricks, all bets are off with the SQL queries.Andrey
> > > > _
> > > > From: Valentin Kulichenko <valentin.kuliche...@gmail.com>
> > > > Sent: Thursday, February 4, 2016 6:29 AM
> > > > Subject: Re: Transformers in SCAN queries
> > > > To:  <dev@ignite.apache.org>
> > > >
> > > >
> > > >Dmitry,
> > > >
> > > >  The main difference in my view is that you lose pagination when
> > sending
> > > >  results from servers to client. What if one wants to iterate through
> > all
> > > >  entries in cache?
> > > >
> > > >  On Wed, Feb 3, 2016 at 9:47 PM, Dmitriy Setrakyan <
> > > dsetrak...@apache.org>
> > > >  wrote:
> > > >
> > > >  > Valentin,
> > > >  >
> > > >  > Wouldn’t the same effect be achieved by broadcasting a closure to
> > the
> > > >  > cluster and executing scan-query on every node locally?
> > > >  >
> > > >  > D.
> > > >  >
> > > >  > On Wed, Feb 3, 2016 at 9:17 PM, Valentin Kulichenko <
> > > >  > valentin.kuliche...@gmail.com> wrote:
> > > >  >
> > > >  > > Igniters,
> > > >  > >
> > > >  > > I keep getting requests from our users to add optional
> > transformers
> > > to
> > > >  > SCAN
> > > >  > > queries. This will allow to iterate through cache, but do not
> > > transfer
> > > >  > > whole key-value pairs across networks (e.g., get only keys). The
> > > > feature
> > > >  > > looks useful and I created a ticket [1].
> > > >  > >
> > > >  > > I am struggling with the design now. The problem is that I
> wanted
> > to
> > > >  > extend
> > > >  > > existing ScanQuery object for this, but this seems to be
> > impossible
> > > >  > because
> > > >  > > it already extends Query<Cache.Entry<K, V>> and thus can iterate
> > > only
> > > >  > > through entries.
> > > >  > >
> > > >  > > The only option I see now is to create a separate query type,
> > > > copy-paste
> > > >  > > everything from ScanQuery and add *mandatory* transformer.
> > Something
> > > > like
> > > >  > > this:
> > > >  > >
> > > >  > > ScanTransformQuery<K, V, R> extends Query {
> > > >  > > IgniteBiPredicate<K, V> filter;
> > > >  > > IgniteClosure<Cache.Entry<K, V>, R> transformer;
> > > >  > > int part;
> > > >  > > ...
> > > >  > > }
> > > >  > >
> > > >  > > Thoughts? Does anyone has other ideas?
> > > >  > >
> > > >  > > [1]https://issues.apache.org/jira/browse/IGNITE-2546
> > > >  > >
> > > >  > > -Val
> > > >  > >
> > > >  >
> > > >
> > > >
> > > >
> > > >
> > > >
> > >
> > >
> > >
> > > --
> > > Andrey Gura
> > > GridGain Systems, Inc.
> > > www.gridgain.com
> > >
> >
>
>
>
> --
> Andrey Gura
> GridGain Systems, Inc.
> www.gridgain.com
>

Re: Transformers in SCAN queries

2016-02-04 Thread Semyon Boikov

I think scan query implementation can be more complex than just sending
closures to all nodes. e.g. it should handle topology changes. IMO it is
not good idea to use compute instead of queries.

On Thu, Feb 4, 2016 at 10:55 AM, Dmitriy Setrakyan 
wrote:

> On Wed, Feb 3, 2016 at 10:28 PM, Valentin Kulichenko <
> valentin.kuliche...@gmail.com> wrote:
>
> > Dmitry,
> >
> > The main difference in my view is that you lose pagination when sending
> > results from servers to client. What if one wants to iterate through all
> > entries in cache?
> >
>
> I see. Perhaps we should fix the pagination for compute instead of adding
> transformers for queries?
>
>
> >
> > On Wed, Feb 3, 2016 at 9:47 PM, Dmitriy Setrakyan  >
> > wrote:
> >
> > > Valentin,
> > >
> > > Wouldn’t the same effect be achieved by broadcasting a closure to the
> > > cluster and executing scan-query on every node locally?
> > >
> > > D.
> > >
> > > On Wed, Feb 3, 2016 at 9:17 PM, Valentin Kulichenko <
> > > valentin.kuliche...@gmail.com> wrote:
> > >
> > > > Igniters,
> > > >
> > > > I keep getting requests from our users to add optional transformers
> to
> > > SCAN
> > > > queries. This will allow to iterate through cache, but do not
> transfer
> > > > whole key-value pairs across networks (e.g., get only keys). The
> > feature
> > > > looks useful and I created a ticket [1].
> > > >
> > > > I am struggling with the design now. The problem is that I wanted to
> > > extend
> > > > existing ScanQuery object for this, but this seems to be impossible
> > > because
> > > > it already extends Query> and thus can iterate only
> > > > through entries.
> > > >
> > > > The only option I see now is to create a separate query type,
> > copy-paste
> > > > everything from ScanQuery and add *mandatory* transformer. Something
> > like
> > > > this:
> > > >
> > > > ScanTransformQuery extends Query {
> > > > IgniteBiPredicate filter;
> > > > IgniteClosure, R> transformer;
> > > > int part;
> > > > ...
> > > > }
> > > >
> > > > Thoughts? Does anyone has other ideas?
> > > >
> > > > [1] https://issues.apache.org/jira/browse/IGNITE-2546
> > > >
> > > > -Val
> > > >
> > >
> >
>

Re: Transformers in SCAN queries

2016-02-04 Thread Andrey Kornev

Another perhaps bigger problem with running queries (including scan queries) 
using closures was discussed at length on the @dev not so long ago. It has to 
do with partitions migration due to cluster topology changes which may result 
in the query returning incomplete result. And while it is possible to solve 
this problem for the scan queries by using some clever tricks, all bets are off 
with the SQL queries.Andrey
_
From: Valentin Kulichenko <valentin.kuliche...@gmail.com>
Sent: Thursday, February 4, 2016 6:29 AM
Subject: Re: Transformers in SCAN queries
To:  <dev@ignite.apache.org>

   Dmitry,   

 The main difference in my view is that you lose pagination when sending   
 results from servers to client. What if one wants to iterate through all   
 entries in cache?   

 On Wed, Feb 3, 2016 at 9:47 PM, Dmitriy Setrakyan <dsetrak...@apache.org>   
 wrote:   

 > Valentin,   
 >   
 > Wouldn’t the same effect be achieved by broadcasting a closure to the   
 > cluster and executing scan-query on every node locally?   
 >   
 > D.   
 >   
 > On Wed, Feb 3, 2016 at 9:17 PM, Valentin Kulichenko <   
 > valentin.kuliche...@gmail.com> wrote:   
 >   
 > > Igniters,   
 > >   
 > > I keep getting requests from our users to add optional transformers to   
 > SCAN   
 > > queries. This will allow to iterate through cache, but do not transfer   
 > > whole key-value pairs across networks (e.g., get only keys). The feature   
 > > looks useful and I created a ticket [1].   
 > >   
 > > I am struggling with the design now. The problem is that I wanted to   
 > extend   
 > > existing ScanQuery object for this, but this seems to be impossible   
 > because   
 > > it already extends Query<Cache.Entry<K, V>> and thus can iterate only   
 > > through entries.   
 > >   
 > > The only option I see now is to create a separate query type, copy-paste   
 > > everything from ScanQuery and add *mandatory* transformer. Something like  
 > >  
 > > this:   
 > >   
 > > ScanTransformQuery<K, V, R> extends Query {   
 > > IgniteBiPredicate<K, V> filter;   
 > > IgniteClosure<Cache.Entry<K, V>, R> transformer;   
 > > int part;   
 > > ...   
 > > }   
 > >   
 > > Thoughts? Does anyone has other ideas?   
 > >   
 > > [1]https://issues.apache.org/jira/browse/IGNITE-2546   
 > >   
 > > -Val   
 > >   
 >

Re: Transformers in SCAN queries

2016-02-03 Thread Valentin Kulichenko

Dmitry,

The main difference in my view is that you lose pagination when sending
results from servers to client. What if one wants to iterate through all
entries in cache?

On Wed, Feb 3, 2016 at 9:47 PM, Dmitriy Setrakyan 
wrote:

> Valentin,
>
> Wouldn’t the same effect be achieved by broadcasting a closure to the
> cluster and executing scan-query on every node locally?
>
> D.
>
> On Wed, Feb 3, 2016 at 9:17 PM, Valentin Kulichenko <
> valentin.kuliche...@gmail.com> wrote:
>
> > Igniters,
> >
> > I keep getting requests from our users to add optional transformers to
> SCAN
> > queries. This will allow to iterate through cache, but do not transfer
> > whole key-value pairs across networks (e.g., get only keys). The feature
> > looks useful and I created a ticket [1].
> >
> > I am struggling with the design now. The problem is that I wanted to
> extend
> > existing ScanQuery object for this, but this seems to be impossible
> because
> > it already extends Query> and thus can iterate only
> > through entries.
> >
> > The only option I see now is to create a separate query type, copy-paste
> > everything from ScanQuery and add *mandatory* transformer. Something like
> > this:
> >
> > ScanTransformQuery extends Query {
> > IgniteBiPredicate filter;
> > IgniteClosure, R> transformer;
> > int part;
> > ...
> > }
> >
> > Thoughts? Does anyone has other ideas?
> >
> > [1] https://issues.apache.org/jira/browse/IGNITE-2546
> >
> > -Val
> >
>

Re: Transformers in SCAN queries

2016-02-03 Thread Dmitriy Setrakyan

Valentin,

Wouldn’t the same effect be achieved by broadcasting a closure to the
cluster and executing scan-query on every node locally?

D.

On Wed, Feb 3, 2016 at 9:17 PM, Valentin Kulichenko <
valentin.kuliche...@gmail.com> wrote:

> Igniters,
>
> I keep getting requests from our users to add optional transformers to SCAN
> queries. This will allow to iterate through cache, but do not transfer
> whole key-value pairs across networks (e.g., get only keys). The feature
> looks useful and I created a ticket [1].
>
> I am struggling with the design now. The problem is that I wanted to extend
> existing ScanQuery object for this, but this seems to be impossible because
> it already extends Query> and thus can iterate only
> through entries.
>
> The only option I see now is to create a separate query type, copy-paste
> everything from ScanQuery and add *mandatory* transformer. Something like
> this:
>
> ScanTransformQuery extends Query {
> IgniteBiPredicate filter;
> IgniteClosure, R> transformer;
> int part;
> ...
> }
>
> Thoughts? Does anyone has other ideas?
>
> [1] https://issues.apache.org/jira/browse/IGNITE-2546
>
> -Val
>

Re: Transformers in SCAN queries

2016-02-03 Thread Dmitriy Setrakyan

On Wed, Feb 3, 2016 at 10:28 PM, Valentin Kulichenko <
valentin.kuliche...@gmail.com> wrote:

> Dmitry,
>
> The main difference in my view is that you lose pagination when sending
> results from servers to client. What if one wants to iterate through all
> entries in cache?
>

I see. Perhaps we should fix the pagination for compute instead of adding
transformers for queries?


>
> On Wed, Feb 3, 2016 at 9:47 PM, Dmitriy Setrakyan 
> wrote:
>
> > Valentin,
> >
> > Wouldn’t the same effect be achieved by broadcasting a closure to the
> > cluster and executing scan-query on every node locally?
> >
> > D.
> >
> > On Wed, Feb 3, 2016 at 9:17 PM, Valentin Kulichenko <
> > valentin.kuliche...@gmail.com> wrote:
> >
> > > Igniters,
> > >
> > > I keep getting requests from our users to add optional transformers to
> > SCAN
> > > queries. This will allow to iterate through cache, but do not transfer
> > > whole key-value pairs across networks (e.g., get only keys). The
> feature
> > > looks useful and I created a ticket [1].
> > >
> > > I am struggling with the design now. The problem is that I wanted to
> > extend
> > > existing ScanQuery object for this, but this seems to be impossible
> > because
> > > it already extends Query> and thus can iterate only
> > > through entries.
> > >
> > > The only option I see now is to create a separate query type,
> copy-paste
> > > everything from ScanQuery and add *mandatory* transformer. Something
> like
> > > this:
> > >
> > > ScanTransformQuery extends Query {
> > > IgniteBiPredicate filter;
> > > IgniteClosure, R> transformer;
> > > int part;
> > > ...
> > > }
> > >
> > > Thoughts? Does anyone has other ideas?
> > >
> > > [1] https://issues.apache.org/jira/browse/IGNITE-2546
> > >
> > > -Val
> > >
> >
>

Re: Transformers in SCAN queries

Re: Transformers in SCAN queries

Re: Transformers in SCAN queries

Re: Transformers in SCAN queries

Re: Transformers in SCAN queries

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