- users-list - monetdb.org

[MonetDB-users] stethoscope on OS X can't connect to database
by Viktor Rosenfeld 07 Dec '11

07 Dec '11

Hi, when I try to connect to a database with stethoscope I get an error: $ stethoscope -d annis_test -u annis_test -P ... +tis stethoscope: no databases found for 'annis_test' I'm using the Aug2011-SP3 release on OS X 10.6.8. The same command works under Linux. The instances are set up identically. Cheers, Viktor

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[MonetDB-users] JDBC documentation inconsistencies
by Viktor Rosenfeld 29 Nov '11

29 Nov '11

Hi, the example at the top of the documentation of the JDBC client at http://www.monetdb.org/Documentation/Cookbooks/SQLrecipies/Clients/JDBC uses the -d switch to specify the table and the -b switch to specify the database. However the current version does not recognize the -b switch and the -d switch can be used to select the database as is documented further on the page. Also, the page says that TRACE is not possible via JDBC. However, as the jdbcclient.jar demonstrates it is indeed possible to use TRACE on a query by checking additional result sets. Cheers, Viktor

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[MonetDB-users] Announcement: New Aug2011-SP3 Bugfix release of MonetDB suite
by Fabian Groffen 22 Nov '11

22 Nov '11

The MonetDB team at CWI/MonetDB BV is pleased to announce the Aug2011-SP3 bugfix release of the MonetDB suite of programs. More information about MonetDB can be found on our website at http://www.monetdb.org/. For details on this release, please see the release notes at <http://www.monetdb.org/Downloads/ReleaseNotes>. As usual, the download location is <http://dev.monetdb.org/downloads/>. Note that this is the last release of the Aug2011 branch. From now on, no further development will take place on this branch. Aug 2011-SP3 bugfix release SQL * Added a fix for bug #2834, which caused weird (failing) behaviour with PreparedStatements. Merovingian * Fixed a bug where monetdbd's socket files from /tmp were removed when a second monetdbd was attempted to be started using the same port. Bug Fixes * 2875: incomplete database initialization * 2912: Function body disappears after loading data - error message: SQLException:sql.resultSet:Cannot access descriptor * 2919: Add column and select in same transaction * 2920: Updated database from Aug2011 to Dec2011 make queries fail with "Subquery result missing". * 2921: complex where clause broken * 2923: Multiplication and cast from decimal to integer leads to 0 value * 2924: use LIKE with ESCAPE ignores OR operator * 2928: Cannot update a field with a count query based on an other table

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[MonetDB-users] Workflow for independent, read only, discretely updated tables.
by Hedge Hog 20 Nov '11

20 Nov '11

Hi, I'm evaluating MonetDB, and the following is based on reading the docs and some of the monetdb-users email list archive. I wonder if the following setup+workflow is correct, and if so, is it monetdb best practice, given this use case: We will have read only tables, each distributed across several machines/servers, they will be updated daily. There will be no cross table queries, i.e. only one table touched by each quert. We would like to be able to update each table while not affecting the availability of any other table. The table_db's are not horizontally sharded, i.e. all the data for a query will always come from that one table. We cannot use udp multicast/broadcast so a monetdb cluster is not possible (unless a localhost cluster is possible/sensible?). The setup+workflow: - one table per database (this allows for independent table updates), let these be <table_db>. - update a master (writable) instance of the table on a 'special' monetdbd/machine. - copy the updated table to each machine. - To update the table on a machine: $> monetbd lock <mytable_db> $> monetbd stop <mytable_db> $> mclient -u monetdb <mytable_db> updatefile $> cat updatefile copy into MyTable from ('path_to_mytable_col_file_i', 'path_to_mytable_col_file_f', 'path_to_mytable_col_file_s'); $> monetbd release <mytable_db> $> monetbd start <mytable_db> Is the above the best pattern/architecture of monetdb for such a use case? Appreciate any insights people can offer TIA Hedge -- πόλλ' οἶδ ἀλώπηξ, ἀλλ' ἐχῖνος ἓν μέγα [The fox knows many things, but the hedgehog knows one big thing.] Archilochus, Greek poet (c. 680 BC – c. 645 BC) http://hedgehogshiatus.com

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[MonetDB-users] Unable to use Tableau
by Sékine Coulibaly 18 Nov '11

18 Nov '11

Hi there, I'm a new user to both Tableau and MonetDb. I run under Windows, and my MonetDb base is up and running, a table "matable" was created and populated. Although I can connect the MonetDb base to Tableau (although I get some warnings), as soon as Tableau sends a request to MonetDb, the ODBC driver returns the following : « Database error (0x80004005) : [MonetDB][ODBC Driver 11.5.7]Invalid identifier 'none:name:nk' » As can be seen here : http://puu.sh/8STw Has any of you already used Tableau and solved this issue ? Shall I consider using Pentaho ? Thank you ! Regards

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[MonetDB-users] pcre not found when configure monetdb5
by xldelg＠sohu.com 18 Nov '11

18 Nov '11

hi, I tried to compile the latest monetdb(11.5.3) on centos6 x64, but the pcre library is not found when configure. I'm sure that the pcre library has been installed via compiling the source, the libpcre.la, libpcre.a, libpcre.so has been installed in /usr/local/lib. I also configure monetdb like: pcre_LIBS=/usr/local/lib pcre_CFLAGS=/usr/local/include ./configure, but it doesn't work. How to fix this problem? Any reply will be apprecitated.    

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[MonetDB-users] "TypeException: algebra.join undefined" when evaluating EXISTS (SELECT ...) predicate
by Viktor Rosenfeld 16 Nov '11

16 Nov '11

Hi, I get an error message when executing the following query: SELECT count(*) FROM _rank AS _rank1, _rank AS _rank2 WHERE _rank1.pre = 23 AND _rank2.pre = 33 AND EXISTS (SELECT 1 FROM _rank AS ancestor WHERE ancestor.pre < _rank1.pre AND _rank1.pre < ancestor.post AND ancestor.pre < _rank2.pre AND _rank2.pre < ancestor.post); The error message is: TypeException:user.s0_1[99]:'algebra.join' undefined in: _129:any := algebra.join(_128:bat[:oid,:oid], _108:bat[:int,:oid]) SQLException:SQLengine:Program contains errors A minimal example of test data to run this query follows: CREATE TABLE _rank (pre INTEGER, post INTEGER); INSERT INTO _rank VALUES (22, 37); INSERT INTO _rank VALUES (23, 24); INSERT INTO _rank VALUES (33, 34); Cheers, Viktor

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[MonetDB-users] General Questions on Columnar DB Design and Querying
by Sean McNamara 13 Nov '11

13 Nov '11

Hi all, I've managed to get MonetDB running and loaded with a chunk of data (thanks to some great help from the list) and am now trying to figure out the "right" way to make use of it. I don't have a whole lot of exposure to columnar stores, and am therefore not sure if I'm doing things in an idiomatically correct way. I have a couple general questions about columnar DBs, and hope its appropriate to ask them here even thought they aren't specific to MonetDB. If these questions aren't considered appropriate for this list I apologize in advance and will happily move them to a different forum (but would appreciate pointers to where such a forum might be.) Two questions are general, and one is fairly specific. First the general: 1. Does working with a columnar store fundamentally change the way one would structure the tables? I'm somewhat familiar with star-schema designs where a central fact table holds the entire attribute set in as rows of indexes with supporting lookup tables for each column type, but it seems like columnar stores achieve the same thing without actually requiring the developer to specifically build those structures. Tables are constructed in a de-normalized RDBMS manner and the underlying DB takes care of the vectorization. Is this a valid description, or am I fundamentally misunderstanding the basics? 2. If there are significant differences in the way columnar stores should be designed, can folks point me to any resources (web, book, article, etc.) to help educate me on the topic? Now the specific: I have several sets of time-series data modeled as follows: create table sensordata ( sensor varchar(32), epoch_ts bigint, reading double, CONSTRAINT SENSORDATA_PKEY PRIMARY KEY (sensor, epoch_ts) ); I've populated that data, and now want to query data for a subset of sensors and generate a table that shows the value of the sensors at each point in time. I'm not sure what the right way to do this is. My desired out:ut would be: epoch_ts sensor1 sensor2 delta -------------- ------------ ------------ ------ <time1> 23.5 24.1 0.6 <time2> 19.3 25.2 5.9 ... <timeN> 25.1 19.3 -5.8 I tried to build that query as follows but end up with NULL results (note: I'm in no way a SQL pro so it might be really ugly.) select a.epoch_ts as epoch, a.reading as sensor1_reading, b.reading as sensor2_reading, b.reading - a.reading as delta from (select epoch_ts, reading from sensordata where sensor='sensor1') a, (select epoch_ts, reading from sensordata where sensor='sensor2') b where b.epoch_ts = a.epoch_ts order by epoch asc; Is this a sane way to approach the problem, or am I completely off track here. Each subselect returns results, but they obviously aren't joining correctly and it feels like it might simply be the wrong way to try to build the result set. I appreciate any direction you might provide. Thanks!

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[MonetDB-users] MonetDB Permission/COPY INTO Questions
by Sean McNamara 13 Nov '11

13 Nov '11

Hi All, I'm just staring to play with MonetDB, but am running into some trouble with a few basic tasks. I've managed to create a new DB and have added a table. I'd now like to bulk-load the table with a CSV file full of data. When I try to do so, I get the following: WS3:~ tank$ mclient -u testuser testdb Welcome to mclient, the MonetDB/SQL interactive terminal (Aug2011) Database: MonetDB v11.5.1, 'testdb' Type \q to quit, \? for a list of available commands auto commit mode: on sql>COPY 1800 records into testdata from 'testdata.csv'; COPY INTO: insufficient privileges: COPY INTO from file(s) requires administrator rights, use 'COPY INTO "testdata" FROM STDIN' instead I then try to copy into via STDIN: WS3:~ tank$ mclient -u testuser -s "COPY 1800 records into testdata from STDIN using delimiters ',';" testdb < testdata.csv WS3:~ tank$ mclient -u testuser testdb Welcome to mclient, the MonetDB/SQL interactive terminal (Aug2011) Database: MonetDB v11.5.1, 'testdb' Type \q to quit, \? for a list of available commands auto commit mode: on sql>select * testdb; +-----+-----+------+ | foo | bar | baz | +===+==+===+ +-----+-----+------+ 0 tuples (2.307ms) sql> It seems clear I have some sort of permission/privilege issue, but I'm not clear how to resolve it. I've looked at all the tables and see the auths, users, user_role, and other tables, but it's not clear what actually needs to be tweaked there or if I should be using other DB commands to set things up. I've tried signing on as the monetdb user to do the import, but the monetdb user doesn't appear to be able to see the table: WS3:~ tank$ mclient -u monetdb testdb password: Welcome to mclient, the MonetDB/SQL interactive terminal (Aug2011) Database: MonetDB v11.5.1, 'testdb' Type \q to quit, \? for a list of available commands auto commit mode: on sql>COPY 1800 records into testdata from 'testdata.csv'; COPY INTO: no such table 'testdata' I realize this should all be quite simple, but am not finding my way forward. I've been searching the archives and hunting on google but am coming up empty. Can anyone point the way? Thanks!

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[MonetDB-users] General questions on columnar DB design and querying
by Sean McNamara 13 Nov '11

13 Nov '11

Hi all, I've managed to get MonetDB running and loaded with a chunk of data (thanks to some great help from the list) and am now trying to figure out the "right" way to make use of it. I don't have a whole lot of exposure to columnar stores, and am therefore not sure if I'm doing things in an idiomatically correct way. I have a couple general questions about columnar DBs, and hope its appropriate to ask them here even thought they aren't specific to MonetDB. If these questions aren't considered appropriate for this list I apologize in advance and will happily move them to a different forum (but would appreciate pointers to where such a forum might be.) Two questions are general, and one is fairly specific. First the general: 1. Does working with a columnar store fundamentally change the way one would structure the tables? I'm somewhat familiar with star-schema designs where a central fact table holds the entire attribute set in as rows of indexes with supporting lookup tables for each column type, but it seems like columnar stores achieve the same thing without actually requiring the developer to specifically build those structures. Tables are constructed in a de-normalized RDBMS manner and the underlying DB takes care of the vectorization. Is this a valid description, or am I fundamentally misunderstanding the basics? 2. If there are significant differences in the way columnar stores should be designed, can folks point me to any resources (web, book, article, etc.) to help educate me on the topic? Now the specific: I have several sets of time-series data modeled as follows: create table sensordata ( sensor varchar(32), epoch_ts bigint, reading double, CONSTRAINT SENSORDATA_PKEY PRIMARY KEY (sensor, epoch_ts) ); I've populated that data, and now want to query data for a subset of sensors and generate a table that shows the value of the sensors at each point in time. I'm not sure what the right way to do this is. My desired out:ut would be: epoch_ts sensor1 sensor2 delta -------------- ------------ ------------ ------ <time1> 23.5 24.1 0.6 <time2> 19.3 25.2 5.9 ... <timeN> 25.1 19.3 -5.8 I tried to build that query as follows but end up with NULL results (note: I'm in no way a SQL pro so it might be really ugly.) select a.epoch_ts as epoch, a.reading as sensor1_reading, b.reading as sensor2_reading, b.reading - a.reading as delta from (select epoch_ts, reading from sensordata where sensor='sensor1') a, (select epoch_ts, reading from sensordata where sensor='sensor2') b where b.epoch_ts = a.epoch_ts order by epoch asc; Is this a sane way to approach the problem, or am I completely off track here. Each subselect returns results, but they obviously aren't joining correctly and it feels like it might simply be the wrong way to try to build the result set. I appreciate any direction you might provide. Thanks!

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