users-list July 2011

users-list@monetdb.org

15 participants
14 discussions

[MonetDB-users] MonetDB JDBC 1.9 question

by Charalampos Nikolaou

Hi, I am getting some strange exceptions using MonetDB JDBC 1.8/1.9, and I decided to look into the code. While inspecting the code I came across these strange lines in MonetConnection.executeQuery(String[] templ, String query) method (http://dev.monetdb.org/hg/MonetDB/file/718da8ca0a1a/java/src/nl/cwi/monetdb…). In my case, these lines are executed for sure when doing a batch insert. So, suppose that the batch contains the following commands (as constructed by the MonetStatement.executeBatch() method): exec 1(1, 957339737330229055); exec 1(2, 278262503670654331); exec 1(805306369, 3763943296910752235) The lines in question take the above commands as a string, prepend a 's' character and append a ';' at the end. The resulting commands, which are written in the server's socket, are the following: sexec 1(1, 957339737330229055); exec 1(2, 278262503670654331); exec 1(805306369, 3763943296910752235); First of all, I am not familiar with the internals of JDBC drivers. Taking this into account, is this what it should be? From a symmetric point of view, I would assume that the correct would be the following: sexec 1(1, 957339737330229055); sexec 1(2, 278262503670654331); sexec 1(805306369, 3763943296910752235); That is, it should prepend a 's' character before an exec command. Last, are these exec commands (with or without a prepending 's') specific to MonetDB? In either case, is there any documentation to get familiar with their meaning? Thanks a lot, Babis

10 years, 5 months

[MonetDB-users] protocol violation: unexpected line in data block

by tangray

the whole log file : RD 1298855541531: read final block: 57 bytes RX 1298855541531: onxRWd3Yv:mserver:9:RIPEMD160,SHA256,SHA1,MD5:LIT:SHA512: RD 1298855541531: inserting prompt TD 1298855541531: write final block: 92 bytes TX 1298855541531: BIG:risk:{SHA256}01fa94fefcadb5918473e49aaa8e425538f8d40960b2d649348cb17c599031ae:sql:krisk: RD 1298855541546: read final block: 0 bytes RX 1298855541546: RD 1298855541546: inserting prompt TD 1298855541546: write final block: 48 bytes TX 1298855541546: sSET TIME ZONE INTERVAL '+08:00' HOUR TO MINUTE; RD 1298855541546: read final block: 0 bytes RX 1298855541546: RD 1298855541546: inserting prompt TD 1298855541546: write final block: 15 bytes TX 1298855541546: Xreply_size 250 RD 1298855541546: read final block: 0 bytes RX 1298855541546: RD 1298855541546: inserting prompt TD 1298855541546: write final block: 46 bytes TX 1298855541546: sSELECT "name", "value" FROM sys.env() as env; RD 1298855541546: read final block: 4246 bytes RX 1298855541546: &1 0 46 2 46 % .env, .env # table_name % name, value # name % varchar, varchar # type % 18, 203 # length [ "gdk_arch", "32biti686-pc-win32" ] [ "gdk_version", "1.40.3" ] [ "prefix", "D:\\Program Files\\MonetDB\\MonetDB5" ] [ "exec_prefix", "D:\\Program Files\\MonetDB\\MonetDB5" ] [ "gdk_dbname", "krisk" ] [ "gdk_dbfarm", "C:\\Documents and Settings\\swordtan\\Application Data\\MonetDB5\\dbfarm" ] [ "gdk_debug", "0" ] [ "gdk_alloc_map", "no" ] [ "gdk_vmtrim", "yes" ] [ "monet_admin", "adm" ] [ "monet_prompt", ">" ] [ "monet_welcome", "yes" ] [ "monet_mod_path", "D:\\Program Files\\MonetDB\\MonetDB5\\lib\\MonetDB5;D:\\Program Files\\MonetDB\\MonetDB5\\lib\\MonetDB5\\lib;D:\\Program Files\\MonetDB\\MonetDB5\\lib\\MonetDB5\\bin" ] [ "monet_daemon", "no" ] [ "host", "localhost" ] [ "mapi_port", "50000" ] [ "mapi_clients", "2" ] [ "mapi_open", "true" ] [ "mapi_autosense", "false" ] [ "default_pipe", "inline,remap,evaluate,costModel,coercions,emptySet,aliases,mitosis,mergetable,deadcode,commonTerms,joinPath,reorder,deadcode,reduce,dataflow,history,multiplex,garbageCollector" ] [ "minimal_pipe", "inline,remap,deadcode,multiplex,garbageCollector" ] [ "sql_optimizer", "default_pipe" ] [ "sql_debug", "0" ] [ "standoff_ns", "" ] [ "standoff_start", "start" ] [ "standoff_end", "end" ] [ "config", "D:\\Program Files\\MonetDB\\MonetDB5\\etc\\monetdb5.conf" ] [ "mero_pidfile", "D:\\Program Files\\MonetDB\\MonetDB5\\var\\run\\MonetDB\\merovingian.pid" ] [ "mero_controlport", "50001" ] [ "nov2009_pipe", "inline,remap,evaluate,costModel,coercions,emptySet,aliases,mergetable,deadcode,constants,commonTerms,joinPath,deadcode,reduce,dataflow,history,multiplex,garbageCollector" ] [ "replication_pipe", "inline,remap,evaluate,costModel,coercions,emptySet,aliases,mergetable,deadcode,constants,commonTerms,joinPath,deadcode,reduce,dataflow,history,replication,multiplex,garbageCollector" ] [ "accumulator_pipe", "inline,remap,evaluate,costModel,coercions,emptySet,aliases,mergetable,deadcode,constants,commonTerms,joinPath,deadcode,reduce,accumulators,dataflow,history,multiplex,garbageCollector" ] [ "recycler_pipe", "inline,remap,evaluate,costModel,coercions,emptySet,aliases,deadcode,constants,commonTerms,joinPath,deadcode,recycle,reduce,dataflow,history,multiplex,garbageCollector" ] [ "cracker_pipe", "inline,remap,evaluate,costModel,coercions,emptySet,aliases,selcrack,deadcode,constants,commonTerms,joinPath,deadcode,reduce,dataflow,history,multiplex,garbageCollector" ] [ "sidcrack_pipe", "inline,remap,evaluate,costModel,coercions,emptySet,aliases,sidcrack,deadcode,constants,commonTerms,joinPath,deadcode,reduce,dataflow,history,multiplex,garbageCollector" ] [ "datacell_pipe", "inline,remap,evaluate,costModel,coercions,emptySet,aliases,deadcode,constants,commonTerms,joinPath,datacell,deadcode,reduce,dataflow,history,multiplex,garbageCollector" ] [ "octopus_pipe", "inline,remap,evaluate,costModel,coercions,emptySet,aliases,mitosis,mergetable,deadcode,constants,commonTerms,joinPath,octopus,deadcode,reduce,dataflow,history,multiplex,garbageCollector" ] [ "mapreduce_pipe", "inline,remap,evaluate,costModel,coercions,emptySet,aliases,mapreduce,mergetable,deadcode,commonTerms,joinPath,reorder,deadcode,reduce,dataflow,history,multiplex,garbageCollector" ] [ "datacyclotron_pipe", "inline,remap,evaluate,costModel,coercions,emptySet,aliases,datacyclotron,mergetable,deadcode,constants,commonTerms,joinPath,reorder,deadcode,reduce,dataflow,history,replication,multiplex,garbageCollector" ] [ "derive_pipe", "inline,remap,evaluate,costModel,coercions,emptySet,aliases,mergetable,deadcode,constants,commonTerms,derivePath,joinPath,deadcode,reduce,dataflow,history,multiplex,garbageCollector" ] [ "dictionary_pipe", "inline,remap,dictionary,evaluate,costModel,coercions,emptySet,aliases,mergetable,deadcode,constants,commonTerms,joinPath,deadcode,reduce,dataflow,history,multiplex,garbageCollector" ] [ "compression_pipe", "inline,remap,evaluate,costModel,coercions,emptySet,aliases,mergetable,deadcode,constants,commonTerms,joinPath,deadcode,reduce,dataflow,compression,dataflow,history,multiplex,garbageCollector" ] [ "gdk_mem_pagebits", "16" ] [ "gdk_mem_bigsize", "1048576" ] [ "monet_pid", "984" ] [ "monet_version", "5.22.3" ] RD 1298855541546: inserting prompt TD 1298855541562: write final block: 60 bytes TX 1298855541562: sselect * from risk.td_ind_security_held where id = 1560000; RD 1298855541578: read final block: 1600 bytes RX 1298855541578: &1 1 1 30 1 % risk.td_ind_security_held, risk.td_ind_security_held, risk.td_ind_security_held, risk.td_ind_security_held, risk.td_ind_security_held, risk.td_ind_security_held, risk.td_ind_security_held, risk.td_ind_security_held, risk.td_ind_security_held, risk.td_ind_security_held, risk.td_ind_security_held, risk.td_ind_security_held, risk.td_ind_security_held, risk.td_ind_security_held, risk.td_ind_security_held, risk.td_ind_security_held, risk.td_ind_security_held, risk.td_ind_security_held, risk.td_ind_security_held, risk.td_ind_security_held, risk.td_ind_security_held, risk.td_ind_security_held, risk.td_ind_security_held, risk.td_ind_security_held, risk.td_ind_security_held, risk.td_ind_security_held, risk.td_ind_security_held, risk.td_ind_security_held, risk.td_ind_security_held, risk.td_ind_security_held # table_name % id, bizdate, painnercode, currency, exchange, seccode, basickind, unrealizedgainchange, unrealizedgain, margingain, interestgain, othergain, yieldrate, accrualinterest, allgain, fullmv, marketvalue, lastfullmv, lastmarketvalue, lastcost, cost, buysum, sellsum, realizedgain, holdingqty, lastholdingqty, mvweight, lastmvweight, fullmvweight, lastfullmvweight # name % int, varchar, varchar, varchar, varchar, varchar, varchar, decimal, decimal, decimal, decimal, decimal, decimal, decimal, decimal, decimal, decimal, decimal, decimal, decimal, decimal, decimal, decimal, decimal, decimal, decimal, decimal, decimal, decimal, decimal # type % 7, 8, 8, 3, 5, 6, 3, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 14, 14, 14, 14 # length RD 1298855541578: inserting prompt TD 1298855762109: write final block: 60 bytes TX 1298855762109: sselect * from risk.td_ind_security_held where id = 1560000; RD 1298855762125: read final block: 1600 bytes RX 1298855762125: &1 2 1 30 1 % risk.td_ind_security_held, risk.td_ind_security_held, risk.td_ind_security_held, risk.td_ind_security_held, risk.td_ind_security_held, risk.td_ind_security_held, risk.td_ind_security_held, risk.td_ind_security_held, risk.td_ind_security_held, risk.td_ind_security_held, risk.td_ind_security_held, risk.td_ind_security_held, risk.td_ind_security_held, risk.td_ind_security_held, risk.td_ind_security_held, risk.td_ind_security_held, risk.td_ind_security_held, risk.td_ind_security_held, risk.td_ind_security_held, risk.td_ind_security_held, risk.td_ind_security_held, risk.td_ind_security_held, risk.td_ind_security_held, risk.td_ind_security_held, risk.td_ind_security_held, risk.td_ind_security_held, risk.td_ind_security_held, risk.td_ind_security_held, risk.td_ind_security_held, risk.td_ind_security_held # table_name % id, bizdate, painnercode, currency, exchange, seccode, basickind, unrealizedgainchange, unrealizedgain, margingain, interestgain, othergain, yieldrate, accrualinterest, allgain, fullmv, marketvalue, lastfullmv, lastmarketvalue, lastcost, cost, buysum, sellsum, realizedgain, holdingqty, lastholdingqty, mvweight, lastmvweight, fullmvweight, lastfullmvweight # name % int, varchar, varchar, varchar, varchar, varchar, varchar, decimal, decimal, decimal, decimal, decimal, decimal, decimal, decimal, decimal, decimal, decimal, decimal, decimal, decimal, decimal, decimal, decimal, decimal, decimal, decimal, decimal, decimal, decimal # type % 7, 8, 8, 3, 5, 6, 3, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 14, 14, 14, 14 # length RD 1298855762125: inserting prompt TD 1298856279453: write final block: 69 bytes TX 1298856279453: sselect id,bizdate from risk.td_ind_security_held where id = 1560000; RD 1298856279453: read final block: 162 bytes RX 1298856279453: &1 3 1 2 1 % risk.td_ind_security_held, risk.td_ind_security_held # table_name % id, bizdate # name % int, varchar # type % 7, 8 # length [ 1560000, "20090702" ] RD 1298856279453: inserting prompt TD 1298856279468: write final block: 1797 bytes TX 1298856279468: sSELECT 'krisk' AS "TABLE_CAT", "schemas"."name" AS "TABLE_SCHEM", "tables"."name" AS "TABLE_NAME", "columns"."name" AS "COLUMN_NAME", cast(CASE "columns"."type" WHEN 'wrd' THEN -5 WHEN 'sec_interval' THEN -5 WHEN 'bigint' THEN -5 WHEN 'timetz' THEN 92 WHEN 'char' THEN 1 WHEN 'int' THEN 4 WHEN 'clob' THEN 2005 WHEN 'month_interval' THEN 4 WHEN 'tinyint' THEN -6 WHEN 'table' THEN 2003 WHEN 'date' THEN 91 WHEN 'double' THEN 8 WHEN 'decimal' THEN 3 WHEN 'timestamptz' THEN 93 WHEN 'timestamp' THEN 93 WHEN 'blob' THEN 2004 WHEN 'real' THEN 7 WHEN 'time' THEN 92 WHEN 'oid' THEN 1111 WHEN 'boolean' THEN 16 WHEN 'smallint' THEN 5 WHEN 'varchar' THEN 12 ELSE 1111 END AS smallint) AS "DATA_TYPE", "columns"."type" AS "TYPE_NAME", "columns"."type_digits" AS "COLUMN_SIZE", "columns"."type_scale" AS "DECIMAL_DIGITS", 0 AS "BUFFER_LENGTH", 10 AS "NUM_PREC_RADIX", cast(CASE "null" WHEN true THEN 1 WHEN false THEN 0 END AS int) AS "NULLABLE", cast(null AS varchar(1)) AS "REMARKS", "columns"."default" AS "COLUMN_DEF", 0 AS "SQL_DATA_TYPE", 0 AS "SQL_DATETIME_SUB", 0 AS "CHAR_OCTET_LENGTH", "columns"."number" + 1 AS "ORDINAL_POSITION", cast(null AS varchar(1)) AS "SCOPE_CATALOG", cast(null AS varchar(1)) AS "SCOPE_SCHEMA", cast(null AS varchar(1)) AS "SCOPE_TABLE", cast(1111 AS smallint) AS "SOURCE_DATA_TYPE", CASE "null" WHEN true THEN CAST ('YES' AS varchar(3)) WHEN false THEN CAST ('NO' AS varchar(3)) END AS "IS_NULLABLE" FROM "sys"."columns" AS "columns", "sys"."tables" AS "tables", "sys"."schemas" AS "schemas" WHERE "columns"."table_id" = "tables"."id" AND "tables"."schema_id" = "schemas"."id" AND LOWER("schemas"."name") LIKE 'risk' AND LOWER("tables"."name") LIKE 'td_ind_security_held' AND LOWER("columns"."name") LIKE 'id' ORDER BY "TABLE_SCHEM", "TABLE_NAME", "ORDINAL_POSITION"; RD 1298856279484: read final block: 853 bytes RX 1298856279484: &1 4 1 22 1 % ., sys.schemas, .tables, .columns, ., .columns, .columns, .columns, ., ., ., ., .columns, ., ., ., ., ., ., ., ., . # table_name % TABLE_CAT, TABLE_SCHEM, TABLE_NAME, COLUMN_NAME, DATA_TYPE, TYPE_NAME, COLUMN_SIZE, DECIMAL_DIGITS, BUFFER_LENGTH, NUM_PREC_RADIX, NULLABLE, REMARKS, COLUMN_DEF, SQL_DATA_TYPE, SQL_DATETIME_SUB, CHAR_OCTET_LENGTH, ORDINAL_POSITION, SCOPE_CATALOG, SCOPE_SCHEMA, SCOPE_TABLE, SOURCE_DATA_TYPE, IS_NULLABLE # name % char, varchar, varchar, varchar, smallint, varchar, int, int, tinyint, tinyint, int, varchar, varchar, tinyint, tinyint, tinyint, int, varchar, varchar, varchar, smallint, varchar # type % 5, 4, 20, 2, 1, 3, 2, 1, 1, 2, 1, 0, 0, 1, 1, 1, 1, 0, 0, 0, 4, 2 # length [ "krisk", "risk", "td_ind_security_held", "id", 4, "int", 32, 0, 0, 10, 0, NULL, NULL, 0, 0, 0, 1, NULL, NULL, NULL, 1111, "NO" ] RD 1298856279484: inserting prompt TD 1298856279500: write final block: 1802 bytes TX 1298856279500: sSELECT 'krisk' AS "TABLE_CAT", "schemas"."name" AS "TABLE_SCHEM", "tables"."name" AS "TABLE_NAME", "columns"."name" AS "COLUMN_NAME", cast(CASE "columns"."type" WHEN 'wrd' THEN -5 WHEN 'sec_interval' THEN -5 WHEN 'bigint' THEN -5 WHEN 'timetz' THEN 92 WHEN 'char' THEN 1 WHEN 'int' THEN 4 WHEN 'clob' THEN 2005 WHEN 'month_interval' THEN 4 WHEN 'tinyint' THEN -6 WHEN 'table' THEN 2003 WHEN 'date' THEN 91 WHEN 'double' THEN 8 WHEN 'decimal' THEN 3 WHEN 'timestamptz' THEN 93 WHEN 'timestamp' THEN 93 WHEN 'blob' THEN 2004 WHEN 'real' THEN 7 WHEN 'time' THEN 92 WHEN 'oid' THEN 1111 WHEN 'boolean' THEN 16 WHEN 'smallint' THEN 5 WHEN 'varchar' THEN 12 ELSE 1111 END AS smallint) AS "DATA_TYPE", "columns"."type" AS "TYPE_NAME", "columns"."type_digits" AS "COLUMN_SIZE", "columns"."type_scale" AS "DECIMAL_DIGITS", 0 AS "BUFFER_LENGTH", 10 AS "NUM_PREC_RADIX", cast(CASE "null" WHEN true THEN 1 WHEN false THEN 0 END AS int) AS "NULLABLE", cast(null AS varchar(1)) AS "REMARKS", "columns"."default" AS "COLUMN_DEF", 0 AS "SQL_DATA_TYPE", 0 AS "SQL_DATETIME_SUB", 0 AS "CHAR_OCTET_LENGTH", "columns"."number" + 1 AS "ORDINAL_POSITION", cast(null AS varchar(1)) AS "SCOPE_CATALOG", cast(null AS varchar(1)) AS "SCOPE_SCHEMA", cast(null AS varchar(1)) AS "SCOPE_TABLE", cast(1111 AS smallint) AS "SOURCE_DATA_TYPE", CASE "null" WHEN true THEN CAST ('YES' AS varchar(3)) WHEN false THEN CAST ('NO' AS varchar(3)) END AS "IS_NULLABLE" FROM "sys"."columns" AS "columns", "sys"."tables" AS "tables", "sys"."schemas" AS "schemas" WHERE "columns"."table_id" = "tables"."id" AND "tables"."schema_id" = "schemas"."id" AND LOWER("schemas"."name") LIKE 'risk' AND LOWER("tables"."name") LIKE 'td_ind_security_held' AND LOWER("columns"."name") LIKE 'bizdate' ORDER BY "TABLE_SCHEM", "TABLE_NAME", "ORDINAL_POSITION"; RD 1298856279515: read final block: 862 bytes RX 1298856279515: &1 5 1 22 1 % ., sys.schemas, .tables, .columns, ., .columns, .columns, .columns, ., ., ., ., .columns, ., ., ., ., ., ., ., ., . # table_name % TABLE_CAT, TABLE_SCHEM, TABLE_NAME, COLUMN_NAME, DATA_TYPE, TYPE_NAME, COLUMN_SIZE, DECIMAL_DIGITS, BUFFER_LENGTH, NUM_PREC_RADIX, NULLABLE, REMARKS, COLUMN_DEF, SQL_DATA_TYPE, SQL_DATETIME_SUB, CHAR_OCTET_LENGTH, ORDINAL_POSITION, SCOPE_CATALOG, SCOPE_SCHEMA, SCOPE_TABLE, SOURCE_DATA_TYPE, IS_NULLABLE # name % char, varchar, varchar, varchar, smallint, varchar, int, int, tinyint, tinyint, int, varchar, varchar, tinyint, tinyint, tinyint, int, varchar, varchar, varchar, smallint, varchar # type % 5, 4, 20, 7, 2, 7, 1, 1, 1, 2, 1, 0, 0, 1, 1, 1, 1, 0, 0, 0, 4, 2 # length [ "krisk", "risk", "td_ind_security_held", "bizdate", 12, "varchar", 8, 0, 0, 10, 0, NULL, NULL, 0, 0, 0, 2, NULL, NULL, NULL, 1111, "NO" ] RD 1298856279515: inserting prompt TD 1298856508906: write final block: 77 bytes TX 1298856508906: sselect id,bizdate,allgain from risk.td_ind_security_held where id = 1560000; RD 1298856508906: read final block: 187 bytes RX 1298856508906: &1 6 1 3 1 % risk.td_ind_security_held, risk.td_ind_security_held, risk.td_ind_security_held # table_name % id, bizdate, allgain # name % int, varchar, decimal # type % 7, 8, 20 # length RD 1298856508906: inserting prompt

10 years, 7 months

[MonetDB-users] Maximum Parallelism and Recommended Hardware for MonetDB

by brien colwell

I set up a MonetDB server for a data mining team on a single node. The node's specs are 32 cores (4x8 AMD 2.3GHz) 128GiB RAM, with the dbfarm on a RAID0 2xSSD (I think they are Intel SSDs). MonetDB on this hardware works well for aggregates and joins on integers, but chugs considerably on inline views with strings and joins with strings. The team usually has 2-3 concurrent jobs at any given time, some materializing new tables, with lots of bulk loading ("copy into ... from file ..."). A typical table size is 2GiB, and queries may join 5-10 tables. When I look at process activity on the node, I usually see each DB's mserver5 process pegged on CPU, using just a single core. Since I rarely see more than one core used per mserver5, I'm starting to think either I haven't configured MonetDB to favor parallel plans, or I chose the wrong hardware for MonetDB. So, as questions to everyone on the list, I'm curious 1) Are there knobs in MonetDB to favor parallel execution plans? 2) What's the ideal hardware for a single-node MonetDB server to support a workload of 2-5 concurrent queries? 3) What's the ideal disk configuration for the above? Brien

10 years, 10 months

[MonetDB-users] How to compress a table

by Alexis Berlemont

Hi, I am currently trying to evaluate MonetDB as a solution to hold significant amounts of data. Because of limited storage capacities, I am trying to enable compression in MonetDB. I did not manage to find any tutorial on that subject, so I did not go very far. I cannot even tell that I wholly understand the problem. According to the page "Documentation->User Guide->compression", I understood that I had to inject a compression optimizer inside a pipeline. This "thing" is supposed to be possible via the setting of a sql environment variable named "optimizer". In the (generated) source file monetdb5/optimizer/opt_pipes.c, I found a default + compression pipeline. Then, in a mclient session, I typed: sql>set optimizer='inline,remap,evaluate,costModel,coercions,emptySet,aliases,mergetable,deadcode,constants,commonTerms,joinPath,deadcode,reduce,dataflow,compression,dataflow,history,multiplex,garbageCollector'; After that, I tried to use a sql function which was supposed to compress (thanks to the zlib) a table: sql.gzcompress sql>call gzcompress(myschema, mytable); Unfortunately, I am stuck here with the error message 'SELECT: identifier 'myschema' unknown'. I think I located the error message in "sql/server/rel_select.c" but I did not manage to deduce anything interesting. Do you have any idea ? Thanks in advance. Alexis.

10 years, 10 months

[MonetDB-users] Vacuum command missing

by Eugene Prokopiev

Hi, I can't find VACUUM command in http://www.monetdb.org/Documentation, I see only vacuum cleaning algorithm mention in http://www.monetdb.org/Documentation/Manuals/SQLreference/Transactions. So, how can phisicaly delete rows after marking them as deleted? -- Thanks, Eugene Prokopiev

10 years, 12 months

[MonetDB-users] RDF support in MonetDB-11.3.7?

by Medha Atre

Hello, While compiling MonetDB-11.3.7 from sources, in the configure options, I saw an option "--enable-rdf". I was wondering how this option can be used to load RDF data directly into MonetDB? MonetDB's documentation on the web could not help much. Any pointers will be appreciated. Thanks in anticipation. Medha

10 years, 12 months

[MonetDB-users] Announcement: New Apr2011-SP2 bugfix release of MonetDB suite

by Sjoerd Mullender

The MonetDB team at CWI/MonetDB BV is pleased to announce the Apr2011-SP2 bug fix release of the MonetDB suite of programs. This is the first release with support for Fedora 15. Fedora 13 is no longer supported. One important bug fix has to do with columns with string (char/varchar) values. There was a bug that could cause exponential growth of the file holding the data for the column. This bug has been fixed. If you have a database that is much larger than you would expect for the amount of data, this might be the cause. The remedy is to dump and restore that database (or just the affected tables). Apart from using up too much space, this bug didn't have any other consequences. More information (including release notes) on this release is available at <http://www.monetdb.org/OldReleaseNotes/Apr2011>. As usual, the download location is <http://dev.monetdb.org/downloads/>. -- Sjoerd Mullender

10 years, 12 months

[MonetDB-users] Problem with Create Function sintaxis

by elarios＠liacs.nl

Hi, I'm using MonetDB over Fedora 15 and the driver monetdb-1.20-jdbc.jar I have problems with the sintaxis of the following function: ----------------------- create function hts.Get_idimage() returns int begin declare idimag int; select max(Imag_id) into idimag from hts.Image; returns idimag+1; end; ----------------------- the error message is: ----------------------- Error: syntax error, unexpected $end, expecting WHILE in: "create function hts.get_idimage() returns int begin declare idimag int;" SQLState: null ErrorCode: 0 Error occured in: create function hts.Get_idimage() returns int begin declare idimag int ----------------------- Can you give me some clues of how to fix this sintaxis error? I've checked the SQL 2003 framework and the script looks fine. Thanks in advance for your help. Enrique.

11 years

[MonetDB-users] Table with 1 000 000 000 rows

by Eugene Prokopiev

Hi, is it possible to store 1 000 000 000 rows in one table or I need to use some partitioning algorithm? -- Thanks, Eugene Prokopiev

11 years

[MonetDB-users] Normalization

by Eugene Prokopiev

Hi, need I use normalization for tables in colum-oriented databases or it will only decreses perfomance without reducing space usage and other advantages? -- Thanks, Eugene Prokopiev

11 years

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users-list July 2011