developers-list September 2015

developers-list@monetdb.org

5 participants
5 discussions

by Vijay Krishna

Hi, I was analysing the Insert performance of MonetDB... I am trying to optimize a process where in a single tuple has to be inserted into a table of 1200 columns, which takes about 7.5 seconds presently... The query has values for only 5 columns out of 1200, yet the speed is still the same.. Is it possible to reduce this time even?? While digging on this, I came across this thread.. https://www.monetdb.org/pipermail/users-list/2005-August/000139.html *What is the insert speed relatively to other DBs? > * > Using SQL, with the current version we won't compete very well. We get > much more acceptable speeds in 'raw' mode, where lots of the parsing > overhead is removed. > > Can anyone please help me understand what is the 'raw' mode that is explained in this thread?? I am using Oct-2014 version on a CentOS machine with 128 GB RAM... Thanks & Regards, Vijayakrishna.P. Mobile : (+91) 9500402305.

6 years, 10 months

Why doesn't MonetDB exploit SIMD feature?

by Xu,Wenjian

Hi, We know that MonetDB excels in application where the database hot-set can be largely held in main-memory, since the physical operators (e.g., hashjoin, sort) are highly optimized for main-memory. But it is strange to me that these operators do not utilize SIMD which a performance-critical feature of modern CPUs. For example, MonetDB use *timsort* as its underlying stable sort algorithm (do_ssort() in gdk/gdk_ssort_impl.h), but I cannot find any SIMD instructions there. Why doesn't MonetDB exploit SIMD feature? or did I miss something? In paper 'Vectorwise: Beyond Column Stores', the authors claim that X100/Vectorwise use SIMD instructions. So my follow-up question is that whether any of X100/Vectorwise's technologies/features has been integrated into MonetDB's code base. Thank you. Best regards, Xu, Wenjian

6 years, 10 months

DbVisualizer support for MonetDB

by Robert Koch

Hi Folks, DbVisualizer is my preferred GUI to MonetDB. DbVis offers capability to write own database profiles for specific DB's. Today I committed a MonetDB database profile for DbVisualizer. https://github.com/dbvisualizer/dbvis-database-profiles/tree/master/monetdb Anyone familiar to DbVis can import and/or improve this profile. There's a free DbVis version, but the Pro offers much more features, which make life easier. BTW, I'm not working for them. :-) Please feel free to write me your desired features by mail or directly into the MD-file inside the monetdb-directory. If possible, I will implement it inte the profile. Best regards Mario

6 years, 10 months

Announcement: New Jul2015 Feature release of MonetDB suite

by Sjoerd Mullender

The MonetDB team at CWI/MonetDB BV is pleased to announce the Jul2015 feature 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/>. Jul 2015 feature release MonetDB5 Server * Implemented batcalc.min and batcalc.max. Made calc.min and calc.max generic so that no other implementations are needed. * Removed function batcalc.ifthen. Build Environment * Upgraded the license to the Mozilla Public License Version 2.0. Client Package * Added a new output format to mclient: --format=expanded (or -fx). In this format, column values are shown in full and below each other. MonetDB Common * BUNtvar and BUNhvar macros no longer work for TYPE_void columns. * Changed interfaces of a lot of GDK-level functions. When they modify a BAT, don't return the same BAT or NULL, but instead return GDK_SUCCEED or GDK_FAIL. * Changed a bunch of hash-related functions to work on the tail column. The functions that have been changed to work on the tail column are: BAThash, BATprepareHash, HASHgonebad, HASHins, and HASHremove. Java Module * Improved JDBC driver to not throw NullPointerException anymore when calling isNullable() or getPrecision() or getScale() or getColumnDisplaySize() or getSchemaName() or getTableName() or getColumnClassName() on a ResultSetMetaData object. * We now compile the Java classes using the latest Java 1.8 version, and we tell it to compile for Java 1.7. SQL * Differences between time, timestamp, and date values now return properly typed interval types (second or month intervals) instead of integers. * Added support for 128-bit integers (called HUGEINT) on platforms that support this. * Removed support for the mseed library. * Removed support for RDF. * Removed DataCell. It was experimental code that was never enabled. Bug Fixes * 2618: Implement master slave scheme * 3361: constants as MAL function parameters prevent intermediate reuse * 3364: Cannot set role back to a user's default role * 3365: Unable to grant object privileges while having a non-default current_role * 3440: Sequence type errors * 3449: mserver crash on start - Freebsd 10 amd64 * 3476: Cannot revoke object access * 3496: autocompletion table names does not work correctly * 3556: when 2 multiplexed functions in MAL plan, only one is mapped correctly to bat<mod>.function primitive * 3564: Request: add support for postgresql specific scalar function: split_part(string text, delimiter text, field int) * 3625: SIGSEGV because mat array can overrun in opt_mergetable.c * 3627: SQRT in CASE does not work as of Oct2014 * 3654: configure --enable-fits requires extra commands after creating a database instance * 3673: mclient 'expanded' row formatter * 3674: Obfuscate event tracing * 3679: No error is given when incorrect timezone value is specified for a timetz column * 3686: Wrong associativity of multiply/divide * 3702: Filter function not found if created in a user schema * 3708: wrong scoping for cross-schema view references * 3716: alter table my_merge_table drop table t1; crashes mserver5 with Segmentation fault * 3724: Wrong size calculation in BATsubjoin * 3730: SAMPLE function not sampling randomly * 3732: memory leak (of InstrRecord) in opt_mergetable * 3733: "(TRUE OR <Exp>) AND <Exp>" is evaluated incorrectly * 3735: python connection with unix_socket * 3736: crash if mclient disconnects abruptly during a query * 3738: Database inconsistency when using savepoint * 3739: CASE statements do not handle NULLs in the IN () operator properly * 3740: select epoch(now()); types timestamptz(7,0) and bigint(64,0) are not equal * 3742: Division By Zero * 3744: cast to int gives different results for decimal than double * 3747: joins fail in the presence of nulls * 3748: Missing META-INF/services/java.sql.Driver in JDBC package * 3753: Hang on json field parsing * 3754: select from a REMOTE TABLE referring local table crashes mserver5 * 3756: column type conversion sticks to subsequent queries * 3758: "COPY INTO ..." doesn't work, if executing from 2 processes concurrently. * 3759: select data from "sys"."rejects" returns unexpected error and when next select data from "sys"."sessions" causes an assertion failure in mal_interpreter.c:646. * 3760: SQL parser has problem with (position of) a scalar subquery in a SELECT-list * 3761: SQL executor has problem with (position of) a subquery in a SELECT-list. Inconsistent behavior. * 3763: JDBC PreparedStatement for a table with 14 Foreign Keys crashing the Database * 3764: DROPping multiple users causes a crash * 3765: Re-granting a revoked privilege does not work * 3766: VIEW not visible if created under a different schema * 3767: CREATE TEMP TABLE using "LIKE" incorrectly handled * 3769: SIGSEGV when combining a cast/column alias with a UNION ALL view * 3770: combined conditions on declared table in User Defined Function definition crashes monetdb * 3771: Owner of the schema loses rights if assumes the monetdb role. * 3772: Any user can grant a role. * 3773: quantile(col, 0) and quantile(col, 1) fail * 3774: mclient is unaware of merge tables and remote tables * 3775: COPY INTO: Backslash preceding field separator kills import * 3778: Crash on remote table schema mismatch * 3779: server crashes on MAX() on SELECT DISTINCT something combo * 3783: Behavioural change in Jul2015 for 'timestamp minus timestamp' * 3784: Assertion failed: (bn->batCapacity >= cnt), function BAT_scanselect, file gdk_select.c, line 1008. * 3785: sum(interval) causes overflow in conversion to bte * 3786: ResultSet.close() never sends Xclose to free resources * 3787: "b and g must be aligned" from complex group/union query * 3791: HEAPextend: failed to extend to 2420077101056

6 years, 10 months

Install Monetdb

by HENGKI EFFENDI

Hi, I try to install Monetdb in Linux RH, when configure there's error message : configure: error: MonetDB/SQL requires bison Please help me, what should i do. Regards Hengki

6 years, 11 months

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developers-list September 2015