- users-list - monetdb.org

[MonetDB-users] MonetDB support for Upserts / On duplicate key ...
by Philippe Hanrigou 20 May '11

20 May '11

Hi, I am trying to operationalize our MonetDB usage and need some advice. What is the best way to do upserts in MonetDB? (https://secure.wikimedia.org/wikipedia/en/wiki/Upsert) Our application stores its data in a reference database (not MonetDB) and need to export some of its (derived) data in MonetDB for our real-time analytics needs. This "population" of MonetDB can happen in a couple of ways: A) In "real-time", on a "one row at a time" basis, when the application detects that it would be valuable to update the analytics information. B) Nightly in a batch oriented basis, to make sure that no information was lost due to a glitch/downtime during the day. C) We also periodically "refresh" all historical data in a batch oriented mode when we find bugs in the way we are deriving the data or what to derive new analytics from the same reference data. And whatever triggered the update, the rule is that the last update "wins" (and contains the full data). I am explaining this to illustrate why upserts would be very convenient. They would allow me to use the same code in all situations (A, B, C) and in "row" mode as well as in "batch" mode. If, as I suspect there is no out-of-the-box support for upserts, what is the best way to achieve them efficiently in batch mode. I am open to any (performant) solution, it does not have to be SQL based. Thanks in advance, - Philippe PS: Thanks a lot for MonetDB, I am completely amazed by its performance for our analytics queries.

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Re: [MonetDB-users] MonetDB-11.3.1 on OpenBSD 4.9 i386 fails during make
by Michael Sioutis 20 May '11

20 May '11

It seems that in OpenBSD sys/sysctl.h requires sys/param.h (http://lists.gnu.org/archive/html/bug-autoconf/2005-08/msg00015.html) I've found this workaround, but I won't test it until tomorrow probably: http://lists.gnu.org/archive/html/bug-autoconf/2005-08/msg00015.html I also don't know exactly how to apply the above workaround (or any other) in the MonetDB Makefile(s ?). On Wed, May 4, 2011 at 6:27 PM, Michael Sioutis <sioutis(a)di.uoa.gr> wrote: > It seems that in OpenBSD sys/sysctl.h requires sys/param.h > (http://lists.gnu.org/archive/html/bug-autoconf/2005-08/msg00015.html) > I've found this workaround, but I won't test it until tomorrow > probably: http://lists.gnu.org/archive/html/bug-autoconf/2005-08/msg00015.html > > I also don't know exactly how to apply the above workaround (or any > other) in the MonetDB Makefile(s ?). > > On Wed, May 4, 2011 at 6:20 PM, Michael Sioutis <papito.dit(a)gmail.com> wrote: >> I can't find any of HAVE_SYS_SYSCTL_H and KERN_PROC_PATHNAME defined >> in my config.log. >> Also, I have a warning about sysctl.h, which is in the >> configuration.log I posted earlier (my first post). >> >> The important part is this: >> configure: WARNING: sys/sysctl.h: present but cannot be compiled >> configure: WARNING: sys/sysctl.h: check for missing prerequisite headers? >> configure: WARNING: sys/sysctl.h: see the Autoconf documentation >> configure: WARNING: sys/sysctl.h: section "Present But Cannot Be Compiled" >> configure: WARNING: sys/sysctl.h: proceeding with the compiler's result >> configure: WARNING: ## ------------------------------- ## >> configure: WARNING: ## Report this to info(a)monetdb.org ## >> configure: WARNING: ## ------------------------------- ## >> >> On Wed, May 4, 2011 at 6:06 PM, Fabian Groffen <Fabian.Groffen(a)cwi.nl> wrote: >>> Thanks for the summarisation! >>> >>> On 04-05-2011 17:56:54 +0300, Michael Sioutis wrote: >>>> To sum it up.. >>>> >>>> add >>>> #include <pthread.h> >>>> #include <pthread_np.h> >>> >>> hmm, do you really need pthread_np.h? That seems like a non-standard >>> header to me. >>> >>>> and... >>>> 2011-05-04 17:44:29 MSG mydb[19795]: !MALException:malInclude:could >>>> not open file: mal_init >>> >>> This indicates some bigger problem... >>> >>>> 2011-05-04 17:44:29 MSG mydb[19795]: #warning: unable to determine binary location, please use --set monet_mod_path=/path/to/... to allow finding modules >>> >>> ... and this causes it. >>> >>> Can you tell me if HAVE_SYS_SYSCTL_H and KERN_PROC_PATHNAME are defined >>> for you? >>> common/utils/mutils.c is apparently unable to find the executable path >>> on OpenBSD. >>> Perhaps KERN_PROC_PATHNAME is not in sys/sysctl.h on OpenBSD? >>> >>> ------------------------------------------------------------------------------ >>> WhatsUp Gold - Download Free Network Management Software >>> The most intuitive, comprehensive, and cost-effective network >>> management toolset available today. Delivers lowest initial >>> acquisition cost and overall TCO of any competing solution. >>> http://p.sf.net/sfu/whatsupgold-sd >>> _______________________________________________ >>> MonetDB-users mailing list >>> MonetDB-users(a)lists.sourceforge.net >>> https://lists.sourceforge.net/lists/listinfo/monetdb-users >>> >> >

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[MonetDB-users] Where [on file] does MonetDB persists the dB?
by Me Anonimous 19 May '11

19 May '11

I uploaded a 1M records, 67M file but can't find anything in the directory indicating dB storage... Thanks!

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[MonetDB-users] feature request (srid support )
by George Garmpis 19 May '11

19 May '11

Hi, I try to use geometries in different reference systems but i don't get the expected results. I create a table with geometries and insert 2 points with different SRID. sql>create table geom(id int, g geometry); operation successful sql>insert into geom values(1, GeomFromText('POINT(100 100)', 4326)); operation successful sql>insert into geom values(2, GeomFromText('POINT(100 100)', 27700)); operation successful When i ask for these SRID i get the same (0) for every point. sql>select id, srid(g) from geom; +------+--------+ | id | srid_g | +======+=+ | 2 | 0 | | 1 | 0 | +------+--------+ Also, if i ask whether these points overlap i don't get the right result. sql>select equals(g1.g, g2.g) from geom g1, geom g2 where g1.id=1 and g2.id =2; +-----------------+ | overlaps_g | +========+ | true | +-----------------+ 1 tuple (4.119ms) I have noticed that function wkbFromText (in file geom/monetdb5/geom.mx), which is used in SQL functions GeomFromText, PointFromText e.t.c., returns a wkb datatype (defined in geom/lib/libgeom.mx) which has not any field for srid. Is srid stored somewhere else (e.g. as metadata of a geometry collumn)? Generally, does monetdb supports different reference systems? If no, will this feature be added ? -- George Garbis

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[MonetDB-users] 'mkey.bulk_rotate_xor_hash' exception
by Steve Elder 18 May '11

18 May '11

With a very simple test, I get the 'mkey.bulk_rotate_xor_hash' exception. After this error, the only way I have found to recover is to drop the table, re-create and repopulate it. * System parameters: o MonetDB-11.3.1 o x86-64 ( note: build was missing a shared library that was subsequently ) o Solaris 10. o 96 GB memory * I create a simple table. create table fluid ( fluid bigint not null, userID int not null default 0, relativeUser bigint not null, typeID tinyint default 127, updateTime timestamp(0) default now(), constraint fluid_pk primary key( fluid, userID ), constraint user_fk1 foreign key ( userID ) references fuser ( userID ) ); create index rel_user_idx1 on fluid ( relativeUser ); create index userID_idx2 on fluid ( userID ); create index rel_user_user_idx1 on fluid ( relativeUser, userID ); create index update_idx1 on fluid ( updateTime ); * Populate it with records ( Note: the number of records does not seem to matter ). * Delete records. It does not appear to matter how many records I delete. Deleting 1 record or deleting all records seems to have the same effect. * Drop the primary key * Do "set optimizer='nov2009_pipe';" * Add the primary key. I always get the mkey.bulk_rotate_xor_hash exception. Here is a snapshot including a trace of a successful 'alter table drop constraint ...' command after NO records have been deleted. When I delete 1 ( or more records ), I get the exception with no trace output. sql>alter table fluid drop constraint fluid_pk; operation successful sql>set optimizer='nov2009_pipe'; sql>trace alter table fluid add constraint fluid_pk primary key( fluid, userID ); operation successful +------+--------------------------------------------------------------------------------------------------------------+ | tick | stmt | : s : : +======+==============================================================================================================+ | 7 | _2 := sql.mvc(); | | 451 | sql.catalog(29,"FLDB",42302696,0); | | 32 | _16:bat[:oid,:lng] <tmp_4741501>[52] := sql.bind(_2=48362568,"FLDB","fluid","fluid",0); | | 22 | _13:bat[:oid,:int] <tmp_4741500>[52] := sql.bind(_2=48362568,"FLDB","fluid","userID",0); | | 15 | _10:bat[:oid,:oid] <tmp_4741364>[0] := sql.bind_dbat(_2=48362568,"FLDB","fluid",1); | | 10 | _12<tmpr_4741364>[0] := bat.reverse(_10=nil:bat[:oid,:oid]); | | 20 | _15<tmp_4741350>[52] := algebra.kdifference(_13=nil:bat[:oid,:int],_12=<tmpr_4741364>[0]); | | 22 | _17<tmp_4741012>[52] := algebra.kdifference(_16=nil:bat[:oid,:lng],_12=nil); | | 11 | _19:bat[:oid,:wrd] <tmp_4741265>[52] := batcalc.hash(_17=<tmp_4741012>[52]); | | 29 | _22<tmp_4741636>[52] := bat.mirror(_17=<tmp_4741012>[52]); | | 16 | _21:bat[:oid,:wrd] <tmp_4741417>[52] := mkey.bulk_rotate_xor_hash(_19=nil:bat[:oid,:wrd],22,_15=<tmp_4741350 | : : >[52]); : | 8 | _23<tmpr_4741636>[52] := bat.reverse(_22=nil); | | 52 | _24<tmp_4741265>[52] := algebra.join(_23=nil,_21=nil:bat[:oid,:wrd]); | | 15 | (ext60<tmp_4741417>[52],grp58<tmp_4741636>[52]) := group.new(_24=<tmp_4741265>[52]); | | 19 | (ext63<tmp_4741417>[52],grp61<tmp_4741636>[52]) := group.derive(ext60=nil,grp58=nil,_17=nil); | | 10 | (ext66<tmp_4741417>[52],grp64<tmp_4741636>[52]) := group.done(ext63=nil,grp61=nil,_15=nil); | | 9 | _31<tmp_4740027>[52] := bat.mirror(ext66=nil); | | 10 | _32:bat[:oid,:wrd] <tmp_4741417>[52] := aggr.count(grp64=nil,grp64=nil,_31=nil); | | 17 | return sum := aggr.sum(b=<tmp_4741417>[52],true); | | 44 | _33:wrd := aggr.sum(_32=<tmp_4741417>:bat[:oid,:wrd][52]); | | 5 | _34 := calc.isnil(_33=52:wrd); | | 7 | _37 := aggr.count(_32=nil:bat[:oid,:wrd]); | | 6 | _36 := calc.ifthenelse(_34=false,0:wrd,_33=52:wrd); | | 5 | _38 := calc.!=(_37=52:wrd,_36=52:wrd); | | 2827 | barrier _53 := language.dataflow(); | | 6 | sql.assert(_38=false,"UPDATE: PRIMARY KEY constraint 'fluid.fluid_pk' violated"); | | 27 | sql.update(_2=48362568,"FLDB","fluid","fluid_pk",_24=nil); | | 5 | sql.exportOperation(""); | | 3724 | user.s1_1(); | +------+--------------------------------------------------------------------------------------------------------------+ 29 tuples (50.262ms) sql>set optimizer='default_pipe'; sql>alter table fluid drop constraint fluid_pk; operation successful sql>delete from fluid where relativeUser = 11111; 1 affected row (1.557ms) sql>trace alter table fluid add constraint fluid_pk primary key( fluid, userID ); MALException:mkey.bulk_rotate_xor_hash:operation failed Operands not synced on head I need to periodically do bulk loads ( 'copy into' ), but also need to be able to periodically delete records from the same table. Is there a resolution to this problem? Thanks Steve

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[MonetDB-users] mclient credentials after install?
by Philippe Hanrigou 17 May '11

17 May '11

Hi, I am trying to get started with MonetDB in order to assess its response time for an in-house dataset. I managed to configure/make/install it on my MacBook Pro (I have joined the custom Portfile I used for this purpose at the end of this email in case it matters). Nevertheless, when I go through the "Getting started" instructions, mclient is asking for credentials that I never had a chance to explicitly set: ph7:~$ monetdbd start ph7:~$ monetdbd get all property value hostname Solaris.local dbfarm /opt/local/var/monetdb5/dbfarm mserver /opt/local/bin/mserver5 logfile merovingian.log pidfile merovingian.pid sockdir /tmp port 50000 controlport 50001 discoveryport 50000 exittimeout 60 forward proxy discoveryttl 600 passphrase <unknown> mapisock /tmp/.s.monetdb.50000 controlsock /tmp/.s.merovingian.50001 ph7:~$ monetdb create demo created database in maintenance mode: demo ph7:~$ monetdb status name state uptime health last crash demo locked ph7:~$ monetdb release demo taken database out of maintenance mode: demo ph7:~$ monetdb status name state uptime health last crash demo stopped ph7:~$ mclient -d demo user(ph7): password: InvalidCredentialsException:checkCredentials:invalid credentials for user 'ph7' Which credentials I am supposed to use to launch mclient? I am willing to try any workaround as, at this point, I am not concerned with security at all. Thanks in advance, - Philippe --------------------------------------------------------- # ph7's custom Portfile # $Id PortSystem 1.0 name MonetDB version 11.3.1 categories databases platforms darwin maintainers nomaintainer description MonetDB is an open-source database system for high-performance applications in data mining, OLAP, GIS, XML Query, text and multimedia retrieval. MonetDB often achieves a significant speed improvement for SQL and XQuery over other open-source systems. homepage http://www.monetdb.org master_sites http://dev.monetdb.org/downloads/sources/Latest/ distfiles MonetDB-${version}.tar.bz2 use_bzip2 yes checksums md5 f48869c87a56604d1c06f7d8243554f9 \ sha1 03a29a5e00a90d5294443ffb849167a2c108302e \ rmd160 c9bcdff333a60aad42dc8504c458335494e749f1 configure.args --enable-debug=no --enable-assert=no --enable-optimize=yes

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[MonetDB-users] Problem with optimizer ?
by Georgios Garmpis 15 May '11

15 May '11

Hi, Please find attached a query (and corresponding schema) that results in mserver5 using more than 1GB of memory and terminating after 6 mins with this output: MAPI = (monetdb) /tmp/.s.monetdb.50000 ACTION= read_line QUERY = PLAN SELECT DISTINCT h3.obj, CASE WHEN u_ENDPOINT.value IS NOT NULL THEN u_ENDPOINT.value WHEN l_ENDPOINT.value IS NOT NULL THEN l_ENDPOINT.value WHEN ll_ENDPOINT.value IS NOT NULL THEN ll_ENDPOINT.value WHEN lu_ENDPOINT.value IS NOT NULL THEN lu_ENDPOINT.value END, NULL FROM triples t0 INNER JOIN triples h1 ON (h1.pred = 21 AND h1.obj = 42 AND h1.subj = t0.subj) INNER JOIN triples h2 ON (h2.pred = 5 AND h2.subj = t0.subj) INNER JOIN triples h3 ON (h3.pred = 20 AND h3.subj = t0.s ERROR = !Connection terminated Is it a problem of optimizer? Any guidelines to deal with it will be appreciated. I also attached merovigian.log. -- George Garbis

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[MonetDB-users] Repeated mmap/munmap calls
by Steve Elder 13 May '11

13 May '11

We are running the April '11 version of MonetDB on multi-core x86-64 hardware running Solaris 10 OS. We are running on a machine with 96GB of memory. The ulimit for memory shows 'unlimited'. We have an application that we believe should be appropriate for MonetDB fast response-time characteristics. We have a very simple schema that includes the following table: create table tuid ( TUID bigint not null, clientID int not null default 0, mafID bigint not null, addrMatch tinyint default 127, lastUsed timestamp(0) default now(), constraint tuid_pk primary key( TUID, clientID ), constraint client_fk1 foreign key ( clientID ) references client ( clientID ) ); The above table currently contains 13.65 million records ( mostly bulk loaded via 'copy into' ). The primary key was dropped and re-added via appropriate 'alter table' statements. There are other 5 other tables in the schema - all with less than 100 records. All 5 tables have fewer than 5 columns. The total size of the database directory in the dbfarm directory is 1.3 GB. Ultimately, the application could have between 500 million and 1 billion records in the above table. Except for one of the other tables, the number of records will be small ( less than 1000 ). We are running a Java application that uses the JDBC interface to query and update the table. Files of 1-3 million records are processed by the application in a given run. Less than 5% of the records require an update to above table ( no other tables are currently updated or inserted to ). When the application is processing these records, we run 'prstat' against 'mserver5' and see via the 'prstat' command the processing load appears to be distributed fairly evenly across many threads. However, occasionally at some point, one thread appears to be using most of the CPU. During these intervals, 'truss' shows 'mserver5' making repeated calls to mmap and munmap. (The calls to mmap have the same value for the mmap size parameter.) These intervals appear to last for many minutes. During these intervals, query response times slow to a crawl. As a result, the overall throughput of the application is disappointing. Given that we are actually accessing a fairly small number of columns all of which should be in memory ( we believe ), it would appear that MonetDB is not functioning properly. It is our belief that MonetDB should be a good fit for this particular application. I should note that we have 3 different MonetDB databases running on the machine ( thus requiring 3 instances of mserver5 ). However, two of the databases are idle when we run the above application. Given the amount of memory available the size of the database, the number of columns being queries ( and/or updated ), and the amount of memory on the machine, the behavior we are observing does not appear to be consistent with descriptions of MonetDB's expected behavior. We have 3 questions: * Is what we are observing concerning the frequency of mmap and munmap calls typical where the mmap size parameter has the same value? * Why would we be mapping columns into memory so frequently when we are not adding records? * Is it typical to have periods where one thread appears to be handling the entire load? * What should we look for concerning the tuning of the x86-64 platform or MonetDB to address these issues? Thanks Steve

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[MonetDB-users] simple load?
by Zoltan Tomory 11 May '11

11 May '11

Sorry to be a bother, but I wonder how hard it is to load a schema or table from ascii text or an .mdb "access" file. I am using the convenient simple console client that is included. Upon searching the list archives, I found some leads which lead me to panic and reflexively consider using Java's Robot class to perform row by row insert operations from the text file. I'm hopeful that there is another way which is both elegant and understandable to a newbie. Thanks in advance. I have loved using MonetDB to organize my information Zoltan -- View this message in context: http://old.nabble.com/simple-load--tp31587056p31587056.html Sent from the monetdb-users mailing list archive at Nabble.com.

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[MonetDB-users] Alter Table
by Henning Grosch 11 May '11

11 May '11

Is it somehow possible to to add a column with alter table behind an specific column? Example: ALTER TABLE xxx ADD COLUMN newCol int AFTER oldCol; Henning

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[MonetDB-users] wrong results for group by queries
by Daniel Boesswetter 05 May '11

05 May '11

Hi, we are using MonetDB (Oct-2010) for analyzing a 250G data warehouse and have found at least one "thing" which might be a serious bug. The simplest scenario that I have found to describe it, is as follows: SELECT comp.id as compid, comp.name, affnets.name as affid FROM toc INNER JOIN app ON toc.application_id=app.id INNER JOIN comp ON app.company_id = comp.id INNER JOIN affnets ON toc.affiliate_network_id=affnets.id GROUP BY compid, comp.name, affid This query is supposed to return all unique company/affnet pairs which occur in the fact table "toc". However, it returns only the unique company-names, each with a random (the first?) affnet. (Of course, this could be accomplished with DISTINCT, but our aim to to aggregate other fields). If I change the query to select app.company_id as compid, comp.name, affnets.name as affid ... or select comp.id as compid, comp.name, affnets.name as affid ... i.e. semantically the same but only with fields from 2 directly joined tables in the GROUP BY, then the result is correct. Question: Is this a bug or are we missing something? Thank you in advance! Daniel

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[MonetDB-users] Records deleted still appear in: select count(*) from table
by Osmin Castillo 05 May '11

05 May '11

Hi guys: After delete some records from a table using a "delete from table where field=value" criteria, why the "select cont(0) from table" still shows the same records count? Maybe the records are only "marked" and not really removed from the table? Thanks in advance Osmin

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[MonetDB-users] System-wide installation as of April11 release
by brien colwell 05 May '11

05 May '11

Hi all, I recently upgraded one machine to the April11 release of MonetDB. In the April11 release, what is the recommended way to start monetdb with the system, as it used to be done with the rc*.d scripts? For me, maybe a bug, the /etc/init.d/monetdb-sql script is broken (Starting MonetDB SQL server: unable to open 'merovingian.log': Permission denied ... and other missing file, permission errors). Currently I can start the server using 'sudo monetdbd', but of course I want the system-wide installation to start with the system. Thanks, Brien

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[MonetDB-users] Inserted table in triggers
by Vassilis Papakonstantinou 04 May '11

04 May '11

Hello, I want to use a trigger to get the last inserted row of a table so i can insert some fields of this row to another table. Is there something like the INSERTED table in sql server so i can get the row? Thanks Vassilis

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[MonetDB-users] MonetDB-11.3.1 on OpenBSD 4.9 i386 fails during make
by Michael Sioutis 04 May '11

04 May '11

Hello, I didn't now whether I should send a bug report about this, because I am not sure whether the problem occurs because of a bug in the MonetDB source code or my current unfamiliarity with OpenBSD. I downloaded the April2011 tarball from here: http://dev.monetdb.org/downloads/sources/Apr2011/ I installed all required libraries/programs and configuration went fine (except some warning parts which I will attach). The configurations is as follows: MonetDB is configured as follows: * Compilation specifics: Host: i386-unknown-openbsd4.9 Compiler: gcc CFLAGS: -g -O2 $(X_CFLAGS) -Wno-declaration-after-statement X_CFLAGS: LDFLAGS: * Enabled/disabled components: common is enabled monetdb5 is enabled sql is enabled geom is disabled (geos library required for geom module) fits is enabled rdf is disabled (by default) unixodbc is enabled java is enabled jdbc is enabled control is enabled testing is enabled * Important options: OID size: 32 bits When I run "make" is crashes giving me these erros (they are also attached): gcc: ../../../common/options/monet_options.c: No such file or directory gcc: no input files *** Error code 1 ... *** Error code 1 ... Mike

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[MonetDB-users] Fwd: wkb representation of a geometry
by Georgios Garmpis 04 May '11

04 May '11

Hi, I need to get the Well Known Binary representation of a geometry but I didn't find any function in documentation to do this. Any ideas? -- George Garbis

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[MonetDB-users] How does MonetDB work
by anjenny 04 May '11

04 May '11

Hey, my name is anjenny and im doin a little research on MonetDB for a project. My Question is How does MonetDB actually work? Greetings anjenny -- View this message in context: http://old.nabble.com/How-does-MonetDB-work-tp31440282p31440282.html Sent from the monetdb-users mailing list archive at Nabble.com.

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[MonetDB-users] Time Interval Overlap
by brien colwell 29 Apr '11

29 Apr '11

Hi all, I have a table that stores a time interval as two timestamps, and want to construct the most efficient query to check whether two intervals in the table overlap. The naive way, using two range conditions [1], seems to choke for large tables. The M5 SQL manual mentions an OVERLAPS operator that, as far as I've read [2], seems to use an optimized interval join algorithm. Can anyone clarify: 1. How to convert a start timestamp and an end timestamp into an interval type 2. How to use the OVERLAPS operator Many thanks. Brien [0] create table intervals as ( id bigint, series_id bigint, start_time timestamp, end_time timestamp ) [1] select a.id as a_id b.id as b_id from intervals a inner join intervals b on b.series_id = a.series_id and b.id < a.id and b.start_time < a.end_time and a.start_time < b.end_time [2] http://monetdb.cwi.nl/XQuery/Documentation/StandOff-Extension.html

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[MonetDB-users] rowcount in monetdb
by Vassilis Papakonstantinou 29 Apr '11

29 Apr '11

Hello all, Is there a way to take the number of rows affected by the last statement just like @@ROWCOUNT in SQL Server or SQL%ROWCOUNT in Oracle? Thanks, Vassilis

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Re: [MonetDB-users] Discontinuation of MonetDB XQuery
by Peter Boncz 29 Apr '11

29 Apr '11

Hi Ryad, There have been plans to port XQuery to MonetDB5, but there has been lack of time and manpower to make this possible. This shortage of resources might change if the database research community regains interest in XQuery in a future. At CWI, a research project, engineering effort must always be justified by ongoing research projects that profit from it. For the moment, it is hard to predict when there will be XML database research projects again, but I would not rule it out. For the moment, you can also just continue to use MonetDB/XQuery. It had not changed much anyway in the past two years, so the change is not dramatic. The software is still available in open source in this April branch of the MonetDB software. So one can still download it in binary, check out the source, change it, compile it and even redistribute it according to the license. CWI for the moment just will not create new releases for it. Peter From: Ryad Ben-El-Kezadri [mailto:ryad.bek@gmail.com] Sent: Friday, April 29, 2011 9:49 AM To: monetdb-users(a)lists.sourceforge.net Subject: [MonetDB-users] Discontinuation of MonetDB XQuery Hello I am a MonetDB XQuery supporter (http://permalink.gmane.org/gmane.comp.db.monetdb.user/3824) and I am sad that it is discontinued. I was very enthusiastic about the software so I was rather excepting an upgrade to MonetDB5. However I am confident that it will be easy to turn my application to MonetDB5. As a basic XQuery user, my questions are threefold: 1)Are there some explanations for this change (flaws in the design of XQuery 2.0, lack of users, performance limitation)? 2)Is MonetDB5 SQL able to store GB of data (as MonetDB XQuery)? Will we observe performance gains for (time ordered) one dimensional data? 3)Is there an equivalent to the XRPC API? Warm regards Ryad

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[MonetDB-users] Discontinuation of MonetDB XQuery
by Ryad Ben-El-Kezadri 29 Apr '11

29 Apr '11

Hello I am a MonetDB XQuery supporter ( http://permalink.gmane.org/gmane.comp.db.monetdb.user/3824) and I am sad that it is discontinued. I was very enthusiastic about the software so I was rather excepting an upgrade to MonetDB5. However I am confident that it will be easy to turn my application to MonetDB5. As a basic XQuery user, my questions are threefold: 1)Are there some explanations for this change (flaws in the design of XQuery 2.0, lack of users, performance limitation)? 2)Is MonetDB5 SQL able to store GB of data (as MonetDB XQuery)? Will we observe performance gains for (time ordered) one dimensional data? 3)Is there an equivalent to the XRPC API? Warm regards Ryad

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[MonetDB-users] Announcement: New Apr2011 feature release of MonetDB suite
by Sjoerd Mullender 28 Apr '11

28 Apr '11

The MonetDB team at CWI/MonetDB BV is pleased to announce the Apr2011 feature release of the MonetDB suite of programs. As announced one month ago to the day (March 28, 2011), this release marks the start of a new era: development of MonetDB4 and MonetDB/XQuery has ceased. Development of the Pathfinder compiler continues unabated at the University of Tübingen [1], but there is no longer a link being maintained with MonetDB. For details on this release, please see the release notes at <http://monetdb.cwi.nl/Development/Releases/Apr2011/>. [1] http://www.pathfinder-xquery.org/ -- Sjoerd Mullender

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[MonetDB-users] invisible join in Monetdb
by Souman Mandal 26 Apr '11

26 Apr '11

Hi, I am a M-tech student at IIT Bombay. Currently I am doing a project to compare the performance of a column store database with implementation of invisible join and without implementation of invisible join. Now I want to use MonetDB for my project. But I have couple of doubts: > Does invisible join is already implemented in MonetDB? > Where can I get the documentation of the source code? > Though I am running mserver5 process, still if I try to execute the command 'monetdb create test' I am getting a error "monetdb: cannot perform: MonetDB Database Server (merovingian) is not running". How to solve this problem. I really need some help. Waiting for some reply. Thanks & Regards, Souman Mandal

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[MonetDB-users] values of type char(n) not always blank padded?
by Ying Zhang 24 Apr '11

24 Apr '11

Hi, I'm wondering if the following results of querying values of the type char(n) (here n = 50), is expected or an error, since char(n) defines a fixed-length, blank padded string: sql>create table a2 (c1 char(5), c2 char(50)); operation successful sql>insert into a2 values ('abc', 'abc'), ('defg', 'defg'); 2 affected rows (2.848ms) sql>select c1, c2 from a2; +-------+----------------------------------------------------+ | c1 | c2 | +=======+====================================================+ | abc | abc | | defg | defg | +-------+----------------------------------------------------+ 2 tuples (1.655ms) sql>select '#' || c1 || '#' || c2 || '#' from a2; +------------------------------------------------------------+ | concat_single_value | +============================================================+ | #abc#abc# | | #defg#defg# | +------------------------------------------------------------+ 2 tuples (2.242ms) LQL The result of the first SELECT shows that c1 and c2 are blank padded (according to the SQL standard). The result of the second SELECT looks a bit strange, are the padding space characters removed or added after the last '#'? Is this the expected result or an error? Thanks, Jennie

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[MonetDB-users] Using COPY with php_mapi and php_monetdb.php
by Henning Grosch 15 Apr '11

15 Apr '11

Hi, at the moment I use the odbc_drive to connect to my monetdb database. In one script I use COPY to get lots of data in my database. Everything works fine. Yesterday is downloaded the latest source files. There I found the php_mapi.inc and the php_monetdb.php with these two files I can now use monetdb in php without odbc. Now I am trying to use COPY and what happens is I get an error that the remote address canceled the socket connection. This only seems to happen with copy anything else works as excpected. So is it possible to use copy with a socket connection? Thanks. Henning

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