- users-list - monetdb.org

[MonetDB-users] Strange things...
by Alexey Mints 23 Apr '12

23 Apr '12

Hello! I have a strange behavior of my MonetDB database. After some actions I run into situation, when queries select * from table1 where {condition1}; and select * from table1 where {condition2}; return the same results (same rows), but select * from table1 where {condition1} and {condition2}; is empty, which is definitely wrong. I cannot see any problems from SQL-side. I am still struggling to get a minimal code producing this bug. Even worse - it is not always occurring under the same … [View More]

2 1

[MonetDB-users] Performance Degredation
by Joseph Brower 13 Apr '12

13 Apr '12

We discussed this a little bit before, but I was called away. Now that I have some time, I'm hoping to discuss this again and hopefully find resolution. Normally our MonetDB instance is running happily and doesn't have any problems. We've limited the number of queries being performed concurrently to the number of cores in the machine, and we do all of our inserts using COPY INTO statements. The problem is that, for no reason that we can see, suddenly MonetDB starts to perform … [View More]

1 0

[MonetDB-users] MonetDB driver for node.js?
by Robert Kosara 05 Apr '12

05 Apr '12

Hello, I am looking for a better database for a project where I am dealing with large numbers of data points, and MonetDB seems like a really interesting choice for that. This is for a web application that is written in JavaScript/node.js, though, so I'm wondering if anybody might be working on a MonetDB driver for node. I know that your focus is on scientific data, and JavaScript might not be a big factor there, but node is gaining a lot of momentum for web applications. Also, is there a way … [View More]

3 2

[MonetDB-users] Funnel
by Joseph Brower 02 Apr '12

02 Apr '12

We're looking at setting up the funnel. We've got 2 database servers that we're planning on using, and we simply want to balance the requests between the two. We don't want any of the multiplexing to take effect. I'm not seeing much as far as guides or how to set this up in the man pages. Does anyone have any good pointers on how to set things up this way? Thanks, Joseph Brower

3 7

[MonetDB-users] MonetDB - Mondrian connection
by Pedro Salgueiro 30 Mar '12

30 Mar '12

Hi guys! I have been trying MonetDB and it's awesome. I tried to connect MonetDB to Mondrian using olap4j. I managed to establish the connection using the MonetDB JDBC, but I have a problem: There are no errors, but it presents the wrong results. Every MDX query returns the right tables, but with all values "zeroed", something like this: ------------------------ Unit Sales ========== 0 ------------------------ I tried to make a simple JDBC connection, and it … [View More]

2 5

[MonetDB-users] Fwd: Re: DB Corruption
by Joseph Brower 27 Mar '12

27 Mar '12

This is what one of my coworkers reports about the problem. both columns are varchar(24). We have confirmed that there are no null values. We have a theory… Approximately every 6 hours, monetdb stops responding to queries and starts thrashing the disk. This behavior has been confirmed without any inserts. Because of this behavior, we routinely stop and start the service. After a restart, the service returns to a normal state. This appears to be the core problem. Our guess is that we … [View More]restarted the service in the middle of a massive import. We will make sure this doesn't happen again, however, we still cannot find any sort of resolution as to why monetdb routinely starts thrashing the disk (on the order of writing 150MB/s) without any inserts, only select queries. Sorry to change the topic, but we're moving on the assumption we corrupted our db by restarting the service in the middle of a massive "INSERT INTO FROM" query. Can you think of any reason why monetdb would need to write to the disk in such an aggressive manner while ONLY serving select queries? This appears to be the core problem. Thanks On Mar 26, 2012, at 9:23 AM, Joseph Brower wrote: > What would you like me to tell them? > > > -------- Original Message -------- > Subject: Re: [MonetDB-users] DB Corruption > Date: Sun, 25 Mar 2012 09:15:24 +0200 > From: Martin Kersten <Martin.Kersten(a)cwi.nl> > Reply-To: Martin.Kersten(a)cwi.nl, Communication channel for MonetDB > users <monetdb-users(a)lists.sourceforge.net> > To: Communication channel for MonetDB users > <monetdb-users(a)lists.sourceforge.net> > > > > What is the column type? > Is the situation repeatable using a fresh database? > > regards, Martin > > On 3/25/12 6:34 AM, Joseph Brower wrote: > > We just checked. There are no nulls in the database at all. > > Additionally, there is only one column that has a different count. > > > > Thanks, > > > > Joseph Brower > > > > On 03/24/2012 09:58 AM, Stefan Manegold wrote: > >> Joseph, > >> > >> since you did not specify your queries in more detail, I assume they are as > >> simple as > >> (1) select count(*) from<your_table>; > >> and > >> (2) select count(single_column) from<your_table>; > >> > >> In that case, you could try the following sanity check: > >> > >> (3) select count(*) from<your_table> where single_column is null; > >> > >> and check whether that returns the difference between your counts. > >> > >> If that indeed returns the difference between your global count(*) and > >> count(single_column), this would confirm the existence of NULL values, and > >> you'd need to invest which of the values in your CVS file have been > >> interpreted as NULL and why. > >> > >> In case the result of queries (2) and (3) do not add up to the number > >> returned by query (1), you might want to check the output(s) of > >> > >> TRACE select count(*) from<your_table>; > >> TRACE select count(single_column) from<your_table>; > >> TRACE select count(*) from<your_table> where single_column is null; > >> > >> (or have us check them, provided/once we find the time). > >> > >> Stefan > >> > >> On Sat, Mar 24, 2012 at 09:37:38AM -0600, Joseph Brower wrote: > >>> There shouldn't be any nulls. The records were all added by a "Copy > >>> Into" command. The files that we imported had no nulls in it at > >>> all. > >>> > >>> On 03/24/2012 01:57 AM, Sjoerd Mullender wrote: > >>>> On 2012-03-24 00:14, Joseph Brower wrote: > >>>>> We were troubleshooting some odd results coming back from our database, > >>>>> and found that it's missing some entries from a column. This appears to > >>>>> be causing some sort of offset. Does anyone have any ideas on what can > >>>>> be done to resolve it or what may have caused it? Is there any > >>>>> information we could send that would be helpful in troubleshooting this > >>>>> or for a bug report? > >>>>> > >>>>> If we do a count(*) and then a count('single_column') we are getting two > >>>>> different results (when they should be indentical) > >>>> count (*) counts all rows, whereas count(single_column) only count > >>>> non-null values. Are there any nulls in the single_column? > >>>> > >>>> > >>>> > >>>> > >>>> ------------------------------------------------------------------------------ > >>>> This SF email is sponsosred by: > >>>> Try Windows Azure free for 90 days Click Here > >>>> http://p.sf.net/sfu/sfd2d-msazure > >>>> > >>>> > >>>> _______________________________________________ > >>>> MonetDB-users mailing list > >>>> MonetDB-users(a)lists.sourceforge.net > >>>> https://lists.sourceforge.net/lists/listinfo/monetdb-users > >>> ------------------------------------------------------------------------------ > >>> This SF email is sponsosred by: > >>> Try Windows Azure free for 90 days Click Here > >>> http://p.sf.net/sfu/sfd2d-msazure > >>> _______________________________________________ > >>> MonetDB-users mailing list > >>> MonetDB-users(a)lists.sourceforge.net > >>> https://lists.sourceforge.net/lists/listinfo/monetdb-users > >> > > > > > > ------------------------------------------------------------------------------ > > This SF email is sponsosred by: > > Try Windows Azure free for 90 days Click Here > > http://p.sf.net/sfu/sfd2d-msazure > > _______________________________________________ > > MonetDB-users mailing list > > MonetDB-users(a)lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/monetdb-users > > ------------------------------------------------------------------------------ > This SF email is sponsosred by: > Try Windows Azure free for 90 days Click Here > http://p.sf.net/sfu/sfd2d-msazure > _______________________________________________ > MonetDB-users mailing list > MonetDB-users(a)lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/monetdb-users [View Less]

2 3

[MonetDB-users] DB Corruption
by Joseph Brower 26 Mar '12

26 Mar '12

We were troubleshooting some odd results coming back from our database, and found that it's missing some entries from a column. This appears to be causing some sort of offset. Does anyone have any ideas on what can be done to resolve it or what may have caused it? Is there any information we could send that would be helpful in troubleshooting this or for a bug report? If we do a count(*) and then a count('single_column') we are getting two different results (when they should be … [View More]

5 6

[MonetDB-users] Example of GUI on top of MonetDB
by Ryad Ben-El-Kezadri 22 Mar '12

22 Mar '12

Hello, We've updated our Java GUI for analyzing network traces on top of MonetDB A HD video trailer is available here : http://www.youtube.com/watch?v=P8EEhttP-NU GPL Source is available here: https://sites.google.com/site/yavista/ Unfortunately it only works on top of MonetDB Xquery but we hope to port it on MonetDB SQL Regards Ryad

1 0

[MonetDB-users] Failure reading in negative bigint
by Nikhil Padmanabhan 22 Mar '12

22 Mar '12

Hello, I have recently started trying out monetdb and have been very impressed by its speed so far. However, I am hitting a failure trying to read in a large negative number (bitmask) into a bigint field; sql>\<test.sql operation successful value '-9223372036854775808' from line 1 field 17 not inserted, expecting type bigint failed to import table I've attached the sql commands to create the table and a test file to this message. As far as I can tell, this should be fine for … [View More]

2 1

[MonetDB-users] Problem with installation from sources
by Stathis Gkotsis 17 Mar '12

17 Mar '12

Hi all, trying to install the latest version of monetdb from sources, I just did: * ./configure --enable-debug --enable-monetdb5 --enable-sql * make and the make install I created a database and now that I try to connect to it, in the log I get: 2012-03-16 17:33:44 MSG merovingian[1729]: starting a proxy failed: cannot get address for hostname '10-04-64bit': Unknown host 2012-03-16 17:33:44 ERR merovingian[1729]: client error: cannot get address for hostname '10-04-64bit': … [View More]

2 1