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• Displaying Many-To-Many Database relationship in VB.NET 2008 with DataGrid, MS SQL 2008

  - by user337501

  Computer bombed while posting this, couldnt find a duplicate question but if there is one, forgive me. So, I've run into a wall. And rather than use a ladder to avoid it, I'd like go through it. I'm setting up what I can best describe as a many-to-many relationship in a database. To examplify, imagine I have three primary tables: Items, Categories, Sections(nevermind the potential redundancy) Then I have another table, Properties. Items, Categories, and Sections can be associated with many properties. A single property can be associated with one, all, or none of the other tables. The best way I can figure to do this is to have join tables make the relationship. i.e. tblItems----(Foreign Key)----tblItems_To_Properties----(Foreign Key)----tblProperties In this example, tblItems simply has an "ItemID" Primary Key. tblItems_To_Properties has its own Primary Key(tblItems_To_PropertiesID), a Foreign Key to the Item(ItemID) and a Foreign key to the Property(PropertyID). The Properties table simply has its primary key(PropertyID) I hope this example isnt too confusing...if I have to I can find a way to put a diagram up or something. My problem is, I want to display this in a DataGrid using the Master-Detail method(DevExpress GridControl). I use the tblItems as a test, and I can see the Items in the parent view, but in the child view I see(understandably) the join table and that is it. My goal is to make it so the Grid ignores the join table and shows the Properties table as the only child. Any help on this method or insight into another solution would be muuuuuuuch appreciat

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• optimizing an sql query using inner join and order by

  - by Sergio B

  I'm trying to optimize the following query without success. Any idea where it could be indexed to prevent the temporary table and the filesort? EXPLAIN SELECT SQL_NO_CACHE `groups`.* FROM `groups` INNER JOIN `memberships` ON `groups`.id = `memberships`.group_id WHERE ((`memberships`.user_id = 1) AND (`memberships`.`status_code` = 1 AND `memberships`.`manager` = 0)) ORDER BY groups.created_at DESC LIMIT 5;` +----+-------------+-------------+--------+--------------------------+---------+---------+---------------------------------------------+------+----------------------------------------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +----+-------------+-------------+--------+--------------------------+---------+---------+---------------------------------------------+------+----------------------------------------------+ | 1 | SIMPLE | memberships | ref | grp_usr,grp,usr,grp_mngr | usr | 5 | const | 5 | Using where; Using temporary; Using filesort | | 1 | SIMPLE | groups | eq_ref | PRIMARY | PRIMARY | 4 | sportspool_development.memberships.group_id | 1 | | +----+-------------+-------------+--------+--------------------------+---------+---------+---------------------------------------------+------+----------------------------------------------+ 2 rows in set (0.00 sec) +--------+------------+-----------------------------------+--------------+-----------------+-----------+-------------+----------+--------+------+------------+---------+ | Table | Non_unique | Key_name | Seq_in_index | Column_name | Collation | Cardinality | Sub_part | Packed | Null | Index_type | Comment | +--------+------------+-----------------------------------+--------------+-----------------+-----------+-------------+----------+--------+------+------------+---------+ | groups | 0 | PRIMARY | 1 | id | A | 6 | NULL | NULL | | BTREE | | | groups | 1 | index_groups_on_name | 1 | name | A | 6 | NULL | NULL | YES | BTREE | | | groups | 1 | index_groups_on_privacy_setting | 1 | privacy_setting | A | 6 | NULL | NULL | YES | BTREE | | | groups | 1 | index_groups_on_created_at | 1 | created_at | A | 6 | NULL | NULL | YES | BTREE | | | groups | 1 | index_groups_on_id_and_created_at | 1 | id | A | 6 | NULL | NULL | | BTREE | | | groups | 1 | index_groups_on_id_and_created_at | 2 | created_at | A | 6 | NULL | NULL | YES | BTREE | | +--------+------------+-----------------------------------+--------------+-----------------+-----------+-------------+----------+--------+------+------------+---------+ +-------------+------------+----------------------------------------------------------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+ | Table | Non_unique | Key_name | Seq_in_index | Column_name | Collation | Cardinality | Sub_part | Packed | Null | Index_type | Comment | +-------------+------------+----------------------------------------------------------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+ | memberships | 0 | PRIMARY | 1 | id | A | 2 | NULL | NULL | | BTREE | | | memberships | 0 | grp_usr | 1 | group_id | A | 2 | NULL | NULL | YES | BTREE | | | memberships | 0 | grp_usr | 2 | user_id | A | 2 | NULL | NULL | YES | BTREE | | | memberships | 1 | grp | 1 | group_id | A | 2 | NULL | NULL | YES | BTREE | | | memberships | 1 | usr | 1 | user_id | A | 2 | NULL | NULL | YES | BTREE | | | memberships | 1 | grp_mngr | 1 | group_id | A | 2 | NULL | NULL | YES | BTREE | | | memberships | 1 | grp_mngr | 2 | manager | A | 2 | NULL | NULL | YES | BTREE | | | memberships | 1 | complex_index | 1 | group_id | A | 2 | NULL | NULL | YES | BTREE | | | memberships | 1 | complex_index | 2 | user_id | A | 2 | NULL | NULL | YES | BTREE | | | memberships | 1 | complex_index | 3 | status_code | A | 2 | NULL | NULL | YES | BTREE | | | memberships | 1 | complex_index | 4 | manager | A | 2 | NULL | NULL | YES | BTREE | | | memberships | 1 | index_memberships_on_user_id_and_status_code_and_manager | 1 | user_id | A | 2 | NULL | NULL | YES | BTREE | | | memberships | 1 | index_memberships_on_user_id_and_status_code_and_manager | 2 | status_code | A | 2 | NULL | NULL | YES | BTREE | | | memberships | 1 | index_memberships_on_user_id_and_status_code_and_manager | 3 | manager | A | 2 | NULL | NULL | YES | BTREE | | +-------------+------------+----------------------------------------------------------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+

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• Problem building STLport NDK r5/ Android

  - by user558299

  Hi all, I'm trying to build STLport for Android. I got the following steps, but they are not working: 1 - Clone STLport repository using: git clone git://stlport.git.sourceforge.net/gitroot/stlport/stlport 2 - Configure environment using : ./configure --target=arm-eabi --with-extra-cxxflags="-fshort-enums" --with-extra-cflags="-fshort-enums" 3 - From src directory build it using make SYSROOT"{MY NDK path}/platforms/android-5/arch-arm/" release-static But I got the following errors: In file included from ../stlport/stl/_alloc.h:45, from ../stlport/memory:29, from dll_main.cpp:41: ../stlport/stl/_new.h:45:24: error: new: No such file or directory In file included from ../stlport/stl/_limits.h:36, from ../stlport/limits:29, from dll_main.cpp:48: ../stlport/stl/_cwchar.h:26:30: error: cstddef: No such file or directory In file included from ../stlport/stl/_utility.h:35, from ../stlport/utility:35, from dll_main.cpp:40: ../stlport/type_traits:889: error: 'declval' was not declared in this scope ../stlport/type_traits:889: error: expected primary-expression before '>' token ../stlport/type_traits:889: error: expected primary-expression before ')' token ../stlport/type_traits:889: error: 'declval' was not declared in this scope ../stlport/type_traits:889: error: expected primary-expression before '>' token ../stlport/type_traits:889: error: expected primary-expression before ')' token ../stlport/type_traits:889: error: ISO C++ forbids declaration of 'decltype' with no type ../stlport/type_traits:889: error: ISO C++ forbids in-class initialization of non-const static member 'decltype' ../stlport/type_traits:889: error: template declaration of 'int std::tr1::detail::decltype' ../stlport/type_traits:942: error: ISO C++ forbids declaration of 'decltype' with no type ../stlport/type_traits:942: error: ISO C++ forbids in-class initialization of non-const static member 'decltype' ../stlport/type_traits:942: error: template declaration of 'int std::tr1::detail::decltype' make: *** [obj/arm-eabi-gcc/so/dll_main.o] Error 1 Is there any include dir or configuration I´m missing? Thanks, Sergio

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• Need help to create database schema for wholesale online tee store

  - by techiepark

  Hi, I'm currently working on wholesale online t-shirt shop. I have done this for fixed quantity and price, and its working fine. Now i need to do this for variable quantity and price. Here is the reference link, like what i have to do. Basic tables i have created are - CREATE TABLE attribute ( attribute_id int(11) NOT NULL auto_increment, name varchar(100) NOT NULL, PRIMARY KEY (attribute_id) ); CREATE TABLE attribute_value ( attribute_value_id int(11) NOT NULL auto_increment, attribute_id int(11) NOT NULL, value varchar(100) NOT NULL, PRIMARY KEY (attribute_value_id), KEY idx_attribute_value_attribute_id (attribute_id) ); CREATE TABLE product ( product_id int(11) NOT NULL auto_increment, name varchar(100) NOT NULL, description varchar(1000) NOT NULL, price decimal(10,2) NOT NULL, image varchar(150) default NULL, thumbnail varchar(150) default NULL, PRIMARY KEY (product_id), FULLTEXT KEY idx_ft_product_name_description (name,description) ); CREATE TABLE product_attribute ( product_id int(11) NOT NULL, attribute_value_id int(11) NOT NULL, PRIMARY KEY (product_id,attribute_value_id) ); I'm not getting how to store the price based on variable quantity. Please help me to create product and its related tables. my requirement is same as above reference link.

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• What's the fastest way to bulk insert a lot of data in SQL Server (C# client)

  - by Andrew

  I am hitting some performance bottlenecks with my C# client inserting bulk data into a SQL Server 2005 database and I'm looking for ways in which to speed up the process. I am already using the SqlClient.SqlBulkCopy (which is based on TDS) to speed up the data transfer across the wire which helped a lot, but I'm still looking for more. I have a simple table that looks like this: CREATE TABLE [BulkData]( [ContainerId] [int] NOT NULL, [BinId] [smallint] NOT NULL, [Sequence] [smallint] NOT NULL, [ItemId] [int] NOT NULL, [Left] [smallint] NOT NULL, [Top] [smallint] NOT NULL, [Right] [smallint] NOT NULL, [Bottom] [smallint] NOT NULL, CONSTRAINT [PKBulkData] PRIMARY KEY CLUSTERED ( [ContainerIdId] ASC, [BinId] ASC, [Sequence] ASC )) I'm inserting data in chunks that average about 300 rows where ContainerId and BinId are constant in each chunk and the Sequence value is 0-n and the values are pre-sorted based on the primary key. The %Disk time performance counter spends a lot of time at 100% so it is clear that disk IO is the main issue but the speeds I'm getting are several orders of magnitude below a raw file copy. Does it help any if I: Drop the Primary key while I am doing the inserting and recreate it later Do inserts into a temporary table with the same schema and periodically transfer them into the main table to keep the size of the table where insertions are happening small Anything else? -- Based on the responses I have gotten, let me clarify a little bit: Portman: I'm using a clustered index because when the data is all imported I will need to access data sequentially in that order. I don't particularly need the index to be there while importing the data. Is there any advantage to having a nonclustered PK index while doing the inserts as opposed to dropping the constraint entirely for import? Chopeen: The data is being generated remotely on many other machines (my SQL server can only handle about 10 currently, but I would love to be able to add more). It's not practical to run the entire process on the local machine because it would then have to process 50 times as much input data to generate the output. Jason: I am not doing any concurrent queries against the table during the import process, I will try dropping the primary key and see if that helps. ~ Andrew

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• Doctrine 1.2: How do i prevent a contraint from being assigned to both sides of a One-to-many relati

  - by prodigitalson

  Is there a way to prevent Doctrine from assigning a contraint on both sides of a one-to-one relationship? Ive tried moving the definition from one side to the other and using owning side but it still places a constraint on both tables. when I only want the parent table to have a constraint - ie. its possible for the parent to not have an associated child. For example iwant the following sql schema essentially: CREATE TABLE `parent_table` ( `child_id` varchar(50) NOT NULL, `id` integer UNSIGNED NOT NULL auto_increment, PRIMARY KEY (`id`) ); CREATE TABLE `child_table` ( `id` integer UNSIGNED NOT NULL auto_increment, `child_id` varchar(50) NOT NULL, PRIMARY KEY (`id`), UNIQUE KEY (`child_id`), CONSTRAINT `parent_table_child_id_FK_child_table_child_id` FOREIGN KEY (`child_id`) REFERENCES `parent_table` (`child_id`) ); However im getting something like this: CREATE TABLE `parent_table` ( `child_id` varchar(50) NOT NULL, `id` integer UNSIGNED NOT NULL auto_increment, PRIMARY KEY (`id`), CONSTRAINT `child_table_child_id_FK_parent_table_child_id` FOREIGN KEY (`child_id`) REFERENCES `child_table` (`child_id`) ); CREATE TABLE `child_table` ( `id` integer UNSIGNED NOT NULL auto_increment, `child_id` varchar(50) NOT NULL, PRIMARY KEY (`id`), UNIQUE KEY (`child_id`), CONSTRAINT `parent_table_child_id_FK_child_table_child_id` FOREIGN KEY (`child_id`) REFERENCES `parent_table` (`child_id`) ); I could just remove the constraint manually or modify my accessors to return/set a single entity in the collection (using a one-to-many) but it seems like there should built in way to handle this. Also im using Symfony 1.4.4 (pear installtion ATM) - in case its an sfDoctrinePlugin issue and not necessarily Doctrine itself.

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• MySQL DDL error creating tables

  - by Alexandstein

  I am attempting to create tables for a MySQL database, but I am having some syntactical issues. It would seem that syntax checking is behaving differently between tables for some reason. While I've gotten all the other tables to go through, the table, 'stock' doesn't seem to be working, despite seeming to use the same syntax patterns. CREATE TABLE users ( user_id SMALLINT UNSIGNED NOT NULL AUTO_INCREMENT, username VARCHAR(30) NOT NULL, password CHAR(41) NOT NULL, date_joined DATETIME NOT NULL, funds DOUBLE UNSIGNED NOT NULL, PRIMARY KEY(user_id), UNIQUE KEY(username) ); CREATE TABLE owned_stocks ( id SMALLINT UNSIGNED NOT NULL AUTO_INCREMENT, user_id SMALLINT UNSIGNED NOT NULL, paid_price DOUBLE UNSIGNED NOT NULL, quantity MEDIUMINT UNSIGNED NOT NULL, purchase_date DATETIME NOT NULL, PRIMARY KEY(id) ); CREATE TABLE tracking_stocks ( ticker VARCHAR(5) NOT NULL, user_id SMALLINT UNSIGNED NOT NULL, PRIMARY KEY(ticker) ); CREATE TABLE stocks ( ticker VARCHAR(5) NOT NULL, last DOUBLE UNSIGNED NOT NULL, high DOUBLE UNSIGNED NOT NULL, low DOUBLE UNSIGNED NOT NULL, company_name VARCHAR(30) NOT NULL, last_updated INT UNSIGNED NOT NULL, change DOUBLE NOT NULL, percent_change DOUBLE NOT NULL, PRIMARY KEY(ticker) ); Am I just missing a really obvious syntactical issue? ERROR: #1064 - You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'change DOUBLE NOT NULL, percent_change DOUBLE NOT NULL, last DOUBLE' at line 4

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• Hibernate MapKeyManyToMany gives composite key where none exists

  - by larsrc

  I have a Hibernate (3.3.1) mapping of a map using a three-way join table: @Entity public class SiteConfiguration extends ConfigurationSet { @ManyToMany @MapKeyManyToMany(joinColumns=@JoinColumn(name="SiteTypeInstallationId")) @JoinTable( name="SiteConfig_InstConfig", joinColumns = @JoinColumn(name="SiteConfigId"), inverseJoinColumns = @JoinColumn(name="InstallationConfigId") ) Map<SiteTypeInstallation, InstallationConfiguration> installationConfigurations = new HashMap<SiteTypeInstallation, InstallationConfiguration>(); ... } The underlying table (in Oracle 11g) is: Name Null Type ------------------------------ -------- ---------- SITECONFIGID NOT NULL NUMBER(19) SITETYPEINSTALLATIONID NOT NULL NUMBER(19) INSTALLATIONCONFIGID NOT NULL NUMBER(19) The key entity used to have a three-column primary key in the database, but is now redefined as: @Entity public class SiteTypeInstallation implements IdResolvable { @Id @GeneratedValue(generator="SiteTypeInstallationSeq", strategy= GenerationType.SEQUENCE) @SequenceGenerator(name = "SiteTypeInstallationSeq", sequenceName = "SEQ_SiteTypeInstallation", allocationSize = 1) long id; @ManyToOne @JoinColumn(name="SiteTypeId") SiteType siteType; @ManyToOne @JoinColumn(name="InstalationRoleId") InstallationRole role; @ManyToOne @JoinColumn(name="InstallationTypeId") InstType type; ... } The table for this has a primary key 'Id' and foreign key constraints+indexes for each of the other columns: Name Null Type ------------------------------ -------- ---------- SITETYPEID NOT NULL NUMBER(19) INSTALLATIONROLEID NOT NULL NUMBER(19) INSTALLATIONTYPEID NOT NULL NUMBER(19) ID NOT NULL NUMBER(19) For some reason, Hibernate thinks the key of the map is composite, even though it isn't, and gives me this error: org.hibernate.MappingException: Foreign key (FK1A241BE195C69C8:SiteConfig_InstConfig [SiteTypeInstallationId])) must have same number of columns as the referenced primary key (SiteTypeInstallation [SiteTypeId,InstallationRoleId]) If I remove the annotations on installationConfigurations and make it transient, the error disappears. I am very confused why it thinks SiteTypeInstallation has a composite key at all when @Id is clearly defining a simple key, and doubly confused why it picks exactly just those two columns. Any idea why this happens? Is it possible that JBoss (5.0 EAP) + Hibernate somehow remembers a mistaken idea of the primary key across server restarts and code redeployments? Thanks in advance, -Lars

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• SQL Server Long Query

  - by thormj

  Ok... I don't understand why this query is taking so long (MSSQL Server 2005): [Typical output 3K rows, 5.5 minute execution time] SELECT dbo.Point.PointDriverID, dbo.Point.AssetID, dbo.Point.PointID, dbo.Point.PointTypeID, dbo.Point.PointName, dbo.Point.ForeignID, dbo.Pointtype.TrendInterval, coalesce(dbo.Point.trendpts,5) AS TrendPts, LastTimeStamp = PointDTTM, LastValue=PointValue, Timezone FROM dbo.Point LEFT JOIN dbo.PointType ON dbo.PointType.PointTypeID = dbo.Point.PointTypeID LEFT JOIN dbo.PointData ON dbo.Point.PointID = dbo.PointData.PointID AND PointDTTM = (SELECT Max(PointDTTM) FROM dbo.PointData WHERE PointData.PointID = Point.PointID) LEFT JOIN dbo.SiteAsset ON dbo.SiteAsset.AssetID = dbo.Point.AssetID LEFT JOIN dbo.Site ON dbo.Site.SiteID = dbo.SiteAsset.SiteID WHERE onlinetrended =1 and WantTrend=1 PointData is the biggun, but I thought its definition should allow me to pick up what I want easily enough: CREATE TABLE [dbo].[PointData]( [PointID] [int] NOT NULL, [PointDTTM] [datetime] NOT NULL, [PointValue] [real] NULL, [DataQuality] [tinyint] NULL, CONSTRAINT [PK_PointData_1] PRIMARY KEY CLUSTERED ( [PointID] ASC, [PointDTTM] ASC ) WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY] ) ON [PRIMARY] GO CREATE NONCLUSTERED INDEX [IX_PointDataDesc] ON [dbo].[PointData] ( [PointID] ASC, [PointDTTM] DESC )WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, SORT_IN_TEMPDB = OFF, IGNORE_DUP_KEY = OFF, DROP_EXISTING = OFF, ONLINE = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY] GO PointData is 550M rows, and Point (source of PointID) is only 28K rows. I tried making an Indexed View, but I can't figure out how to get the Last Timestamp/Value out of it in a compatible way (no Max, no subquery, no CTE). This runs twice an hour, and after it runs I put more data into those 3K PointID's that I selected. I thought about creating LastTime/LastValue tables directly into Point, but that seems like the wrong approach. Am I missing something, or should I rebuild something? (I'm also the DBA, but I know very little about A'ing a DB!)

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• Database design MySQL using foreign keys

  - by dscher

  I'm having some a little trouble understanding how to handle the database end of a program I'm making. I'm using an ORM in Kohana, but am hoping that a generalized understanding of how to solve this issue will lead me to an answer with the ORM. I'm writing a program for users to manage their stock research information. My tables are basically like so: CREATE TABLE tags( id INT AUTO_INCREMENT NOT NULL PRIMARY KEY, tags VARCHAR(30), UNIQUE(tags) ) ENGINE=INNODB DEFAULT CHARSET=utf8; CREATE TABLE stock_tags( id INT AUTO_INCREMENT NOT NULL PRIMARY KEY, tag_id INT NOT NULL, stock_id INT NOT NULL, FOREIGN KEY (tag_id) REFERENCES tags(id), FOREIGN KEY(stock_id) REFERENCES stocks(id) ON DELETE CASCADE ) ENGINE=INNODB DEFAULT CHARSET=utf8; CREATE TABLE notes( id INT AUTO_INCREMENT NOT NULL, stock_id INT NOT NULL, notes TEXT NOT NULL, FOREIGN KEY (stock_id) REFERENCES stocks(id) ON DELETE CASCADE, PRIMARY KEY(id) ) ENGINE=INNODB DEFAULT CHARSET=utf8; CREATE TABLE links( id INT AUTO_INCREMENT NOT NULL, stock_id INT NOT NULL, links VARCHAR(2083) NOT NULL, FOREIGN KEY (stock_id) REFERENCES stocks(id) ON DELETE CASCADE, PRIMARY KEY(id) ) ENGINE=INNODB DEFAULT CHARSET=utf8; How would I get all the attributes of a single stock, including its links, notes, and tags? Do I have to add links, notes, and tags columns to the stocks table and then how do you call it? I know this differs using an ORM and I'd assume that I can use join tables in SQL. Thanks for any help, this will really help me understand the issue a lot better.

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• Using Hibernate with MS ACCESS 2007 Database (Free JDBC Driver)

  - by Quentin T.

  1. I want to do a reverse engineering action with the Hibernate plugin of Eclipse on a MS Access 2007 Database. I'm forced to use a existing MS Access 2007 db. A easy solution is to buy the HXTT. But I want to use a free driver to do my work. So I tried to apply this post : http://www.programmingforfuture.com/2011/06/how-to-use-ms-access-with-hibernate.html (That uses the SQL Server dialect and the driver sun.jdbc.odbc.JdbcOdbcDriver) Unfortunately I have an error that nobody seems to have been on the internet: Exception while generating code Reason : org.hibernate.exception.GenericJDBCException: Error while reading primary key meta data for `c:/myaccessdb.mdb`.TableTest1 I have try to change the primary key on my MS Access DB (deleting all primary key) or to try the reverse engineering on a MS ACCESS with only one table without primary key, but I got all times the problems. 2. The purpose of my job is to transfer daily (weekly) an Oracle 11g database with data from an existing database MS ACCESS 2007. And I thought to use a procedure (Hibernate EJB) Java to be launched automatically every week to do the data transfer. Is this is the best solution ? Configuration : sun.jdbc.odbc.JdbcOdbcDriver v??? Hibernate v3.4 Eclipse ps: If you are a HXTT developer or seller please be indulgent with my post ;). Making money by making people believe that you help, it's bad ! A solution is to use Derby Client driver, as the solution in the post: Does anyone know if Hibernate and java will work effectively with Access? But a clarification of the answer of Rich Seller is required. Could you explain your answer and explain your configuration (hibernate.cfg.xml, persistence.xml and what URL you use in the property name="hibernate.connection.url") without using paying HXTT driver but with the free Derby driver.

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• How to map a Dictionary<string, string> spanning several tables

  - by Kim Johansson

  I have four tables: CREATE TABLE [Languages] ( [Id] INTEGER IDENTITY(1,1) NOT NULL, [Code] NVARCHAR(10) NOT NULL, PRIMARY KEY ([Id]), UNIQUE INDEX ([Code]) ); CREATE TABLE [Words] ( [Id] INTEGER IDENTITY(1,1) NOT NULL, PRIMARY KEY ([Id]) ); CREATE TABLE [WordTranslations] ( [Id] INTEGER IDENTITY(1,1) NOT NULL, [Value] NVARCHAR(100) NOT NULL, [Word] INTEGER NOT NULL, [Language] INTEGER NOT NULL, PRIMARY KEY ([Id]), FOREIGN KEY ([Word]) REFERENCES [Words] ([Id]), FOREIGN KEY ([Language]) REFERENCES [Languages] ([Id]) ); CREATE TABLE [Categories] ( [Id] INTEGER IDENTITY(1,1) NOT NULL, [Word] INTEGER NOT NULL, PRIMARY KEY ([Id]), FOREIGN KEY ([Word]) REFERENCES [Words] ([Id]) ); So you get the name of a Category via the Word - WordTranslation - Language relations. Like this: SELECT TOP 1 wt.Value FROM [Categories] AS c LEFT JOIN [WordTranslations] AS wt ON c.Word = wt.Word WHERE wt.Language = ( SELECT TOP 1 l.Id FROM [Languages] WHERE l.[Code] = N'en-US' ) AND c.Id = 1; That would return the en-US translation of the Category with Id = 1. My question is how to map this using the following class: public class Category { public virtual int Id { get; set; } public virtual IDictionary<string, string> Translations { get; set; } } Getting the same as the SQL query above would be: Category category = session.Get<Category>(1); string name = category.Translations["en-US"]; And "name" would now contain the Category's name in en-US. Category is mapped against the Categories table. How would you do this and is it even possible?

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• MySQL query does not return any data

  - by Alex L

  Hi, I need to retrieve data from a specific time period. The query works fine until I specify the time period. Is there something wrong with the way I specify time period? I know there are many entries within that time-frame. This query returns empty: SELECT stop_times.stop_id, STR_TO_DATE(stop_times.arrival_time, '%H:%i:%s') as stopTime, routes.route_short_name, routes.route_long_name, trips.trip_headsign FROM trips JOIN stop_times ON trips.trip_id = stop_times.trip_id JOIN routes ON routes.route_id = trips.route_id WHERE stop_times.stop_id = 5508 HAVING stopTime BETWEEN DATE_SUB(stopTime,INTERVAL 1 MINUTE) AND DATE_ADD(stopTime,INTERVAL 20 MINUTE); Here is it's EXPLAIN: +----+-------------+------------+--------+------------------+---------+---------+-------------------------------+------+-------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +----+-------------+------------+--------+------------------+---------+---------+-------------------------------+------+-------------+ | 1 | SIMPLE | stop_times | ref | trip_id,stop_id | stop_id | 5 | const | 605 | Using where | | 1 | SIMPLE | trips | eq_ref | PRIMARY,route_id | PRIMARY | 4 | wmata_gtfs.stop_times.trip_id | 1 | | | 1 | SIMPLE | routes | eq_ref | PRIMARY | PRIMARY | 4 | wmata_gtfs.trips.route_id | 1 | | +----+-------------+------------+--------+------------------+---------+---------+-------------------------------+------+-------------+ 3 rows in set (0.00 sec) The query works if I remove the HAVING clause (don't specify time range). Returns: +---------+----------+------------------+-----------------+---------------+ | stop_id | stopTime | route_short_name | route_long_name | trip_headsign | +---------+----------+------------------+-----------------+---------------+ | 5508 | 06:31:00 | "80" | "" | "FORT TOTTEN" | | 5508 | 06:57:00 | "80" | "" | "FORT TOTTEN" | | 5508 | 07:23:00 | "80" | "" | "FORT TOTTEN" | | 5508 | 07:49:00 | "80" | "" | "FORT TOTTEN" | | 5508 | 08:15:00 | "80" | "" | "FORT TOTTEN" | | 5508 | 08:41:00 | "80" | "" | "FORT TOTTEN" | | 5508 | 09:08:00 | "80" | "" | "FORT TOTTEN" | I am using Google Transit format Data loaded into MySQL. The query is supposed to provide stop times and bus routes for a given bus stop. For a bus stop, I am trying to get: Route Name Bus Name Bus Direction (headsign) Stop time The results should be limited only to buses times from 1 min ago to 20 min from now. Please let me know if you could help.

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• Removing "Using temporary; Using filesort" from this MySQL select+join+group by query

  - by claytontstanley

  I have the following query: select t.Chunk as LeftChunk, t.ChunkHash as LeftChunkHash, q.Chunk as RightChunk, q.ChunkHash as RightChunkHash, count(t.ChunkHash) as ChunkCount from chunksubset as t join chunksubset as q on t.ID = q.ID group by LeftChunkHash, RightChunkHash And the following explain table: id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE subsets ref PRIMARY,IDIndex,SubsetIndex SubsetIndex 767 const 522014 "Using where; Using temporary; Using filesort" 1 SIMPLE subsets eq_ref PRIMARY,IDIndex,SubsetIndex PRIMARY 771 sotero.subsets.Id,const 1 "Using where; Using index" 1 SIMPLE c ref IDIndex IDIndex 4 sotero.subsets.Id 12 "Using where" 1 SIMPLE c ref IDIndex IDIndex 4 sotero.subsets.Id 12 note the "using temporary; using filesort". When this query is run, I quickly run out of RAM (presumably b/c of the temp table), and then the HDD kicks in, and the query slows to a halt. I thought it might be an index issue, so I started adding a few that sort of made sense: Table Non_unique Key_name Seq_in_index Column_name Collation Cardinality Sub_part Packed Null Index_type Comment Index_comment chunks 0 PRIMARY 1 ChunkId A 17796190 NULL NULL BTREE chunks 1 ChunkHashIndex 1 ChunkHash A 243783 NULL NULL BTREE chunks 1 IDIndex 1 Id A 1483015 NULL NULL BTREE chunks 1 ChunkIndex 1 Chunk A 243783 NULL NULL BTREE chunks 1 ChunkTypeIndex 1 ChunkType A 2 NULL NULL BTREE chunks 1 chunkHashByChunkIDIndex 1 ChunkHash A 243783 NULL NULL BTREE chunks 1 chunkHashByChunkIDIndex 2 ChunkId A 17796190 NULL NULL BTREE chunks 1 chunkHashByChunkTypeIndex 1 ChunkHash A 243783 NULL NULL BTREE chunks 1 chunkHashByChunkTypeIndex 2 ChunkType A 261708 NULL NULL BTREE chunks 1 chunkHashByIDIndex 1 ChunkHash A 243783 NULL NULL BTREE chunks 1 chunkHashByIDIndex 2 Id A 17796190 NULL NULL BTREE But still using the temporary table. The db engine is MyISAM. How can I get rid of the using temporary; using filesort in this query? Just changing to InnoDB w/o explaining the underlying cause is not a particularly satisfying answer. Besides, if the solution is to just add the proper index, then that's much easier than migrating to another db engine.

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• Mysql slow query: INNER JOIN + ORDER BY causes filesort

  - by Alexander

  Hello! I'm trying to optimize this query: SELECT `posts`.* FROM `posts` INNER JOIN `posts_tags` ON `posts`.id = `posts_tags`.post_id WHERE (((`posts_tags`.tag_id = 1))) ORDER BY posts.created_at DESC; The size of tables is 38k rows, and 31k and mysql uses "filesort" so it gets pretty slow. I tried to use different indexes, no luck. CREATE TABLE `posts` ( `id` int(11) NOT NULL auto_increment, `created_at` datetime default NULL, PRIMARY KEY (`id`), KEY `index_posts_on_created_at` (`created_at`), KEY `for_tags` (`trashed`,`published`,`clan_private`,`created_at`) ) ENGINE=InnoDB AUTO_INCREMENT=44390 DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci CREATE TABLE `posts_tags` ( `id` int(11) NOT NULL auto_increment, `post_id` int(11) default NULL, `tag_id` int(11) default NULL, `created_at` datetime default NULL, `updated_at` datetime default NULL, PRIMARY KEY (`id`), KEY `index_posts_tags_on_post_id_and_tag_id` (`post_id`,`tag_id`) ) ENGINE=InnoDB AUTO_INCREMENT=63175 DEFAULT CHARSET=utf8 +----+-------------+------------+--------+--------------------------+--------------------------+---------+---------------------+-------+-----------------------------------------------------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +----+-------------+------------+--------+--------------------------+--------------------------+---------+---------------------+-------+-----------------------------------------------------------+ | 1 | SIMPLE | posts_tags | index | index_post_id_and_tag_id | index_post_id_and_tag_id | 10 | NULL | 24159 | Using where; Using index; Using temporary; Using filesort | | 1 | SIMPLE | posts | eq_ref | PRIMARY | PRIMARY | 4 | .posts_tags.post_id | 1 | | +----+-------------+------------+--------+--------------------------+--------------------------+---------+---------------------+-------+-----------------------------------------------------------+ 2 rows in set (0.00 sec) What kind of index I need to define to avoid mysql using filesort? Is it possible when order field is not in where clause?

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• How to Map Two Tables To One Class in Fluent NHibernate

  - by Richard Nagle

  I am having a problem with fluent nhiberbate mapping two tables to one class. I have the following database schema: TABLE dbo.LocationName ( LocationId INT PRIMARY KEY, LanguageId INT PRIMARY KEY, Name VARCHAR(200) ) TABLE dbo.Language ( LanguageId INT PRIMARY KEY, Locale CHAR(5) ) And want to build the following class definition: public class LocationName { public virtual int LocationId { get; private set; } public virtual int LanguageId { get; private set; } public virtual string Name { get; set; } public virtual string Locale { get; set; } } Here is my mapping class: public LocalisedNameMap() { WithTable("LocationName"); UseCompositeId() .WithKeyProperty(x => x.LanguageId) .WithKeyProperty(x => x.LocationId); Map(x => x.Name); WithTable("Language", lang => { lang.WithKeyColumn("LanguageId"); lang.Map(x => x.Locale); }); } The problem is with the mapping of the Locale field being from another table, and in particular that the keys between those tables don't match. Whenever I run the application with this mapping I get the following error on startup: Foreign key (FK7FC009CCEEA10EEE:Language [LanguageId])) must have same number of columns as the referenced primary key (LocationName [LanguageId, LocationId]) How do I tell nHibernate to map from LocationName to Language using only the LanguageId field?

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• Do I need to write a trigger for such a simple constraint?

  - by Paul Hanbury

  I really had a hard time knowing what words to put into the title of my question, as I am not especially sure if there is a database pattern related to my problem. I will try to simplify matters as much as possible to get directly to the heart of the issue. Suppose I have some tables. The first one is a list of widget types: create table widget_types ( widget_type_id number(7,0) primary key, description varchar2(50) ); The next one contains icons: create table icons ( icon_id number(7,0) primary key, picture blob ); Even though the users get to select their preferred widget, there is a predefined subset of widgets that they can choose from for each widget type. create table icon_associations ( widget_type_id number(7,0) references widget_types, icon_id number(7,0) references icons, primary key (widget_type_id, icon_id) ); create table icon_prefs ( user_id number(7,0) references users, widget_type_id number(7,0), icon_id number(7,0), primary key (user_id, widget_type_id), foreign key (widget_type_id, icon_id) references icon_associations ); Pretty simple so far. Let us now assume that if we are displaying an icon to a user who has not set up his preferences, we choose one of the appropriate images associated with the current widget. I'd like to specify the preferred icon to display in such a case, and here's where I run into my problem: alter table icon_associations add ( is_preferred char(1) check( is_preferred in ('y','n') ) ) ; I do not see how I can enforce that for each widget_type there is one, and only one, row having is_preferred set to 'y'. I know that in MySQL, I am able to write a subquery in my check constraint to quickly resolve this issue. This is not possible with Oracle. Is my mistake that this column has no business being in the icon_associations table? If not where should it go? Is this a case where, in Oracle, the constraint can only be handled with a trigger? I ask only because I'd like to go the constraint route if at all possible. Thanks so much for your help, Paul

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• PHP: parse $_FILES[] data in multidimesional array

  - by superUntitled

  I having been looking around for an answer to this and have not found an answer anywhere, I am hoping someone has done this before! I have a form that allows for dynamic duplication of the form fields. The form allows for file uploads and text input, so the data is sent in both $_POST and $_FILES arrays. The the initial set of inputs look like this: <input type="text" name="primary[1][text]" /> <input type="file" name="primary[1][file]" /> <input type="text" class="a" name="secondary[1][text][]" /> <input type="file" name="secondary[1][file][]" /> When duplicated the fields are incremented, they look like this: <input type="text" name="primary[2][text]" /> <input type="file" name="primary[2][file]" /> <input type="text" class="a" name="secondary[2][text][]" /> <input type="file" name="secondary[2][file][]" /> To complicate matters, the "secondary" form fields can also be duplicated (thus the [] at the end of the secondary name array. How can I parse the posted $_FILES array? I have tried something like this: foreach ($_FILES['question'] as $f_num) { echo $f['file']['name']; } but I get an "Undefined index: file... " error.

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• Social Networking & Network Affiliations

  - by Code Sherpa

  Hi. I am in the process of planning a database for a social networking project and stumbled upon this url which is a (crude) reverse engineered guess at facebook's schema: http://www.flickr.com/photos/ikhnaton2/533233247/ What is of interest to me is the notion of "Affiliations" and I am trying to fully understand how they work, technically speaking. Where I am somewhat confused is the NetworkID column in the FacebookGroups", "FacebookEvent", and "Affiliations" tables (NID in Affiliations). How are these network affiliations interconnected? In my own project, I have a simple profile table: CREATE TABLE [dbo].[Profiles]( [profileid] [int] IDENTITY(1,1) NOT NULL, [userid] [uniqueidentifier] NOT NULL, [username] [varchar](255) COLLATE Latin1_General_CI_AI NOT NULL, [applicationname] [varchar](255) COLLATE Latin1_General_CI_AI NOT NULL, [isanonymous] [bit] NULL, [lastactivity] [datetime] NULL, [lastupdated] [datetime] NULL, CONSTRAINT [PK__Profiles__1DB06A4F] PRIMARY KEY CLUSTERED ( [profileid] ASC )WITH (IGNORE_DUP_KEY = OFF) ON [PRIMARY], CONSTRAINT [PKProfiles] UNIQUE NONCLUSTERED ( [username] ASC, [applicationname] ASC )WITH (IGNORE_DUP_KEY = OFF) ON [PRIMARY] ) ON [PRIMARY] One profile can have many affiliations. And one affiliation can have many profiles. And I would like to design it in such a way that relationships between affiliations tells me something about the associated profiles. In fact, based on the affiliations that users select, I would like to know how to infer as many things as possible about that person. My question is, how should I be designing my network affiliation tables and how do they operate per my above requirements? A rough SQL schema would be appreciated in your response. Thanks in advance...

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• How to set up a functional macro with parameters in C++?

  - by user1728737

  is there a way that I can make this work? Or do I need to use separate files? #include <iostream> // Necessary using namespace std; long double primary, secondary, tertiary; #define long double mMaxOf2(long double min, long double max) { return ((max > min) ? (max) : (min)); } #define long double mMaxOf3(long double Min, long double Max, long double Mid) { long double Mid = (long double mMaxOf2(long double Min, long double Mid)); long double Max = (long double mMaxOf2(long double Mid, long double Max)); return (Max); } int main() { cout << "Please enter three numbers: "; cin << primary << secondary << tertiary; cout << "The maximum of " << primary << " " << secondary << " " << tertiary; cout << " using mMaxOf3 is " << long double mMaxOf3(primary, secondary, tertiary); return 0; } This is the error that I am getting. |20|error: expected unqualified-id before '{' token|

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• SQL - Query to display average as either "longer than" or "shorter than"

  - by user1840801

  Here are the tables I've created: CREATE TABLE Plane_new (Pnum char(3), Feature varchar2(20), Ptype varchar2(15), primary key (Pnum)); CREATE TABLE Employee_new (eid char(3), ename varchar(10), salary number(7,2), mid char(3), PRIMARY KEY (eid), FOREIGN KEY (mid) REFERENCES Employee_new); CREATE TABLE Pilot_new (eid char(3), Licence char(9), primary key (eid), foreign key (eid) references Employee_new on delete cascade); CREATE TABLE FlightI_new (Fnum char(4), Fdate date, Duration number(2), Pid char(3), Pnum char(3), primary key (Fnum), foreign key (Pid) references Pilot_new (eid), foreign key (Pnum) references Plane_new); And here is the query I must complete: For each flight, display its number, the name of the pilot who implemented the flight and the words ‘Longer than average’ if the flight duration was longer than average or the words ‘Shorter than average’ if the flight duration was shorter than or equal to the average. For the column holding the words ‘Longer than average’ or ‘Shorter than average’ make a header Length. Here is what I've come up with - with no luck! SELECT F.Fnum, E.ename, CASE Length WHEN F.Duration>(SELECT AVG(F.Duration) FROM FlightI_new F) THEN "Longer than average" WHEN F.Duration<=(SELECT AVG(F.Duration) FROM FlightI_new F) THEN 'Shorter than average' END FROM FlightI_new F LEFT OUTER JOIN Employee_new E ON F.Pid=E.eid GROUP BY F.Fnum, E.ename; Where am I going wrong?

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• What's up with LDoms: Part 2 - Creating a first, simple guest

  - by Stefan Hinker

  Welcome back! In the first part, we discussed the basic concepts of LDoms and how to configure a simple control domain.  We saw how resources were put aside for guest systems and what infrastructure we need for them.  With that, we are now ready to create a first, very simple guest domain.  In this first example, we'll keep things very simple.  Later on, we'll have a detailed look at things like sizing, IO redundancy, other types of IO as well as security. For now,let's start with this very simple guest.  It'll have one core's worth of CPU, one crypto unit, 8GB of RAM, a single boot disk and one network port.  CPU and RAM are easy.  The network port we'll create by attaching a virtual network port to the vswitch we created in the primary domain.  This is very much like plugging a cable into a computer system on one end and a network switch on the other.  For the boot disk, we'll need two things: A physical piece of storage to hold the data - this is called the backend device in LDoms speak.  And then a mapping between that storage and the guest domain, giving it access to that virtual disk.  For this example, we'll use a ZFS volume for the backend.  We'll discuss what other options there are for this and how to chose the right one in a later article.  Here we go: root@sun # ldm create mars root@sun # ldm set-vcpu 8 mars root@sun # ldm set-mau 1 mars root@sun # ldm set-memory 8g mars root@sun # zfs create rpool/guests root@sun # zfs create -V 32g rpool/guests/mars.bootdisk root@sun # ldm add-vdsdev /dev/zvol/dsk/rpool/guests/mars.bootdisk \ mars.root@primary-vds root@sun # ldm add-vdisk root mars.root@primary-vds mars root@sun # ldm add-vnet net0 switch-primary mars That's all, mars is now ready to power on.  There are just three commands between us and the OK prompt of mars:  We have to "bind" the domain, start it and connect to its console.  Binding is the process where the hypervisor actually puts all the pieces that we've configured together.  If we made a mistake, binding is where we'll be told (starting in version 2.1, a lot of sanity checking has been put into the config commands themselves, but binding will catch everything else).  Once bound, we can start (and of course later stop) the domain, which will trigger the boot process of OBP.  By default, the domain will then try to boot right away.  If we don't want that, we can set "auto-boot?" to false.  Finally, we'll use telnet to connect to the console of our newly created guest.  The output of "ldm list" shows us what port has been assigned to mars.  By default, the console service only listens on the loopback interface, so using telnet is not a large security concern here. root@sun # ldm set-variable auto-boot\?=false mars root@sun # ldm bind mars root@sun # ldm start mars root@sun # ldm list NAME STATE FLAGS CONS VCPU MEMORY UTIL UPTIME primary active -n-cv- UART 8 7680M 0.5% 1d 4h 30m mars active -t---- 5000 8 8G 12% 1s root@sun # telnet localhost 5000 Trying 127.0.0.1... Connected to localhost. Escape character is '^]'. ~Connecting to console "mars" in group "mars" .... Press ~? for control options .. {0} ok banner SPARC T3-4, No Keyboard Copyright (c) 1998, 2011, Oracle and/or its affiliates. All rights reserved. OpenBoot 4.33.1, 8192 MB memory available, Serial # 87203131. Ethernet address 0:21:28:24:1b:50, Host ID: 85241b50. {0} ok We're done, mars is ready to install Solaris, preferably using AI, of course ;-)  But before we do that, let's have a little look at the OBP environment to see how our virtual devices show up here: {0} ok printenv auto-boot? auto-boot? = false {0} ok printenv boot-device boot-device = disk net {0} ok devalias root /virtual-devices@100/channel-devices@200/disk@0 net0 /virtual-devices@100/channel-devices@200/network@0 net /virtual-devices@100/channel-devices@200/network@0 disk /virtual-devices@100/channel-devices@200/disk@0 virtual-console /virtual-devices/console@1 name aliases We can see that setting the OBP variable "auto-boot?" to false with the ldm command worked.  Of course, we'd normally set this to "true" to allow Solaris to boot right away once the LDom guest is started.  The setting for "boot-device" is the default "disk net", which means OBP would try to boot off the devices pointed to by the aliases "disk" and "net" in that order, which usually means "disk" once Solaris is installed on the disk image.  The actual devices these aliases point to are shown with the command "devalias".  Here, we have one line for both "disk" and "net".  The device paths speak for themselves.  Note that each of these devices has a second alias: "net0" for the network device and "root" for the disk device.  These are the very same names we've given these devices in the control domain with the commands "ldm add-vnet" and "ldm add-vdisk".  Remember this, as it is very useful once you have several dozen disk devices... To wrap this up, in this part we've created a simple guest domain, complete with CPU, memory, boot disk and network connectivity.  This should be enough to get you going.  I will cover all the more advanced features and a little more theoretical background in several follow-on articles.  For some background reading, I'd recommend the following links: LDoms 2.2 Admin Guide: Setting up Guest Domains Virtual Console Server: vntsd manpage - This includes the control sequences and commands available to control the console session. OpenBoot 4.x command reference - All the things you can do at the ok prompt

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• SQL SERVER – Weekly Series – Memory Lane – #052

  - by Pinal Dave

  Let us continue with the final episode of the Memory Lane Series. Here is the list of selected articles of SQLAuthority.com across all these years. Instead of just listing all the articles I have selected a few of my most favorite articles and have listed them here with additional notes below it. Let me know which one of the following is your favorite article from memory lane. 2007 Set Server Level FILLFACTOR Using T-SQL Script Specifies a percentage that indicates how full the Database Engine should make the leaf level of each index page during index creation or alteration. fillfactor must be an integer value from 1 to 100. The default is 0. Limitation of Online Index Rebuld Operation Online operation means when online operations are happening in the database are in normal operational condition, the processes which are participating in online operations does not require exclusive access to the database. Get Permissions of My Username / Userlogin on Server / Database A few days ago, I was invited to one of the largest database company. I was asked to review database schema and propose changes to it. There was special username or user logic was created for me, so I can review their database. I was very much interested to know what kind of permissions I was assigned per server level and database level. I did not feel like asking Sr. DBA the question about permissions. Simple Example of WHILE Loop With CONTINUE and BREAK Keywords This question is one of those questions which is very simple and most of the users get it correct, however few users find it confusing for the first time. I have tried to explain the usage of simple WHILE loop in the first example. BREAK keyword will exit the stop the while loop and control is moved to the next statement after the while loop. CONTINUE keyword skips all the statement after its execution and control is sent to the first statement of while loop. Forced Parameterization and Simple Parameterization – T-SQL and SSMS When the PARAMETERIZATION option is set to FORCED, any literal value that appears in a SELECT, INSERT, UPDATE or DELETE statement is converted to a parameter during query compilation. When the PARAMETERIZATION database option is SET to SIMPLE, the SQL Server query optimizer may choose to parameterize the queries. 2008 Transaction and Local Variables – Swap Variables – Update All At Once Concept Summary : Transaction have no effect over memory variables. When UPDATE statement is applied over any table (physical or memory) all the updates are applied at one time together when the statement is committed. First of all I suggest that you read the article listed above about the effect of transaction on local variant. As seen there local variables are independent of any transaction effect. Simulate INNER JOIN using LEFT JOIN statement – Performance Analysis Just a day ago, while I was working with JOINs I find one interesting observation, which has prompted me to create following example. Before we continue further let me make very clear that INNER JOIN should be used where it cannot be used and simulating INNER JOIN using any other JOINs will degrade the performance. If there are scopes to convert any OUTER JOIN to INNER JOIN it should be done with priority. 2009 Introduction to Business Intelligence – Important Terms & Definitions Business intelligence (BI) is a broad category of application programs and technologies for gathering, storing, analyzing, and providing access to data from various data sources, thus providing enterprise users with reliable and timely information and analysis for improved decision making. Difference Between Candidate Keys and Primary Key Candidate Key – A Candidate Key can be any column or a combination of columns that can qualify as unique key in database. There can be multiple Candidate Keys in one table. Each Candidate Key can qualify as Primary Key. Primary Key – A Primary Key is a column or a combination of columns that uniquely identify a record. Only one Candidate Key can be Primary Key. 2010 Taking Multiple Backup of Database in Single Command – Mirrored Database Backup I recently had a very interesting experience. In one of my recent consultancy works, I was told by our client that they are going to take the backup of the database and will also a copy of it at the same time. I expressed that it was surely possible if they were going to use a mirror command. In addition, they told me that whenever they take two copies of the database, the size of the database, is always reduced. Now this was something not clear to me, I said it was not possible and so I asked them to show me the script. Corrupted Backup File and Unsuccessful Restore The CTO, who was also present at the location, got very upset with this situation. He then asked when the last successful restore test was done. As expected, the answer was NEVER.There were no successful restore tests done before. During that time, I was present and I could clearly see the stress, confusion, carelessness and anger around me. I did not appreciate the feeling and I was pretty sure that no one in there wanted the atmosphere like me. 2011 TRACEWRITE – Wait Type – Wait Related to Buffer and Resolution SQL Trace is a SQL Server database engine technology which monitors specific events generated when various actions occur in the database engine. When any event is fired it goes through various stages as well various routes. One of the routes is Trace I/O Provider, which sends data to its final destination either as a file or rowset. DATEDIFF – Accuracy of Various Dateparts If you want to have accuracy in seconds, you need to use a different approach. In the first example, the accurate method is to find the number of seconds first and then divide it by 60 to convert it in minutes. Dedicated Access Control for SQL Server Express Edition http://www.youtube.com/watch?v=1k00z82u4OI Book Signing at SQLPASS 2012 Who I Am And How I Got Here – True Story as Blog Post If there was a shortcut to success – I want to know. I learnt SQL Server hard way and I am still learning. There are so many things, I have to learn. There is not enough time to learn everything which we want to learn. I am constantly working on it every day. I welcome you to join my journey as well. Please join me in my journey to learn SQL Server – more the merrier. Vacation, Travel and Study – A New Concept Even those who have advanced degrees and went to college for years, or even decades, find studying hard.  There is a difference between studying for a career and studying for a certification.  At least to get a degree there is a variety of subjects, with labs, exams, and practice problems to make things more interesting. Order By Numeric Values Formatted as String We have a table which has a column containing alphanumeric data. The data always has first as an integer and later part as a string. The business need is to order the data based on the first part of the alphanumeric data which is an integer. Now the problem is that no matter how we use ORDER BY the result is not produced as expected. Let us understand this with an example. Resolving SQL Server Connection Errors – SQL in Sixty Seconds #030 – Video One of the most famous errors related to SQL Server is about connecting to SQL Server itself. Here is how it goes, most of the time developers have worked with SQL Server and knows pretty much every error which they face during development language. However, hardly they install fresh SQL Server. As the installation of the SQL Server is a rare occasion unless you are a DBA who is responsible for such an instance – the error faced during installations are pretty rare as well. http://www.youtube.com/watch?v=1k00z82u4OI Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Memory Lane, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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• The Application Architecture Domain

  - by Michael Glas

  I have been spending a lot of time thinking about Application Architecture in the context of EA. More specifically, as an Enterprise Architect, what do I need to consider when looking at/defining/designing the Application Architecture Domain?There are several definitions of Application Architecture. TOGAF says “The objective here [in Application Architecture] is to define the major kinds of application system necessary to process the data and support the business”. FEA says the Application Architecture “Defines the applications needed to manage the data and support the business functions”.I agree with these definitions. They reflect what the Application Architecture domain does. However, they need to be decomposed to be practical.I find it useful to define a set of views into the Application Architecture domain. These views reflect what an EA needs to consider when working with/in the Applications Architecture domain. These viewpoints are, at a high level:Capability View: This view reflects how applications alignment with business capabilities. It is a super set of the following views when viewed in aggregate. By looking at the Application Architecture domain in terms of the business capabilities it supports, you get a good perspective on how those applications are directly supporting the business.Technology View: The technology view reflects the underlying technology that makes up the applications. Based on the number of rationalization activities I have seen (more specifically application rationalization), the phrase “complexity equals cost” drives the importance of the technology view, especially when attempting to reduce that complexity through standardization type activities. Some of the technology components to be considered are: Software: The application itself as well as the software the application relies on to function (web servers, application servers). Infrastructure: The underlying hardware and network components required by the application and supporting application software. Development: How the application is created and maintained. This encompasses development components that are part of the application itself (i.e. customizable functions), as well as bolt on development through web services, API’s, etc. The maintenance process itself also falls under this view. Integration: The interfaces that the application provides for integration as well as the integrations to other applications and data sources the application requires to function. Type: Reflects the kind of application (mash-up, 3 tiered, etc). (Note: functional type [CRM, HCM, etc.] are reflected under the capability view). Organization View: Organizations are comprised of people and those people use applications to do their jobs. Trying to define the application architecture domain without taking the organization that will use/fund/change it into consideration is like trying to design a car without thinking about who will drive it (i.e. you may end up building a formula 1 car for a family of 5 that is really looking for a minivan). This view reflects the people aspect of the application. It includes: Ownership: Who ‘owns’ the application? This will usually reflect primary funding and utilization but not always. Funding: Who funds both the acquisition/creation as well as the on-going maintenance (funding to create/change/operate)? Change: Who can/does request changes to the application and what process to the follow? Utilization: Who uses the application, how often do they use it, and how do they use it? Support: Which organization is responsible for the on-going support of the application? Information View: Whether or not you subscribe to the view that “information drives the enterprise”, it is a fact that information is critical. The management, creation, and organization of that information are primary functions of enterprise applications. This view reflects how the applications are tied to information (or at a higher level – how the Application Architecture domain relates to the Information Architecture domain). It includes: Access: The application is the mechanism by which end users access information. This could be through a primary application (i.e. CRM application), or through an information access type application (a BI application as an example). Creation: Applications create data in order to provide information to end-users. (I.e. an application creates an order to be used by an end-user as part of the fulfillment process). Consumption: Describes the data required by applications to function (i.e. a product id is required by a purchasing application to create an order. Application Service View: Organizations today are striving to be more agile. As an EA, I need to provide an architecture that supports this agility. One of the primary ways to achieve the required agility in the application architecture domain is through the use of ‘services’ (think SOA, web services, etc.). Whether it is through building applications from the ground up utilizing services, service enabling an existing application, or buying applications that are already ‘service enabled’, compartmentalizing application functions for re-use helps enable flexibility in the use of those applications in support of the required business agility. The applications service view consists of: Services: Here, I refer to the generic definition of a service “a set of related software functionalities that can be reused for different purposes, together with the policies that should control its usage”. Functions: The activities within an application that are not available / applicable for re-use. This view is helpful when identifying duplication functions between applications that are not service enabled. Delivery Model View: It is hard to talk about EA today without hearing the terms ‘cloud’ or shared services.  Organizations are looking at the ways their applications are delivered for several reasons, to reduce cost (both CAPEX and OPEX), to improve agility (time to market as an example), etc.  From an EA perspective, where/how an application is deployed has impacts on the overall enterprise architecture. From integration concerns to SLA requirements to security and compliance issues, the Enterprise Architect needs to factor in how applications are delivered when designing the Enterprise Architecture. This view reflects how applications are delivered to end-users. The delivery model view consists of different types of delivery mechanisms/deployment options for applications: Traditional: Reflects non-cloud type delivery options. The most prevalent consists of an application running on dedicated hardware (usually specific to an environment) for a single consumer. Private Cloud: The application runs on infrastructure provisioned for exclusive use by a single organization comprising multiple consumers. Public Cloud: The application runs on infrastructure provisioned for open use by the general public. Hybrid: The application is deployed on two or more distinct cloud infrastructures (private, community, or public) that remain unique entities, but are bound together by standardized or proprietary technology that enables data and application portability. While by no means comprehensive, I find that applying these views to the application domain gives a good understanding of what an EA needs to consider when effecting changes to the Application Architecture domain.Finally, the application architecture domain is one of several architecture domains that an EA must consider when developing an overall Enterprise Architecture. The Oracle Enterprise Architecture Framework defines four Primary domains: Business Architecture, Application Architecture, Information Architecture, and Technology Architecture. Each domain links to the others either directly or indirectly at some point. Oracle links them at a high level as follows:Business Capabilities and/or Business Processes (Business Architecture), links to the Applications that enable the capability/process (Applications Architecture – COTS, Custom), links to the Information Assets managed/maintained by the Applications (Information Architecture), links to the technology infrastructure upon which all this runs (Technology Architecture - integration, security, BI/DW, DB infrastructure, deployment model). There are however, times when the EA needs to narrow focus to a particular domain for some period of time. These views help me to do just that.

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• Quantifying the effects of partition mis-alignment

  - by Matt

  I'm experiencing some significant performance issues on an NFS server. I've been reading up a bit on partition alignment, and I think I have my partitions mis-aligned. I can't find anything that tells me how to actually quantify the effects of mis-aligned partitions. Some of the general information I found suggests the performance penalty can be quite high (upwards of 60%) and others say it's negligible. What I want to do is determine if partition alignment is a factor in this server's performance problems or not; and if so, to what degree? So I'll put my info out here, and hopefully the community can confirm if my partitions are indeed mis-aligned, and if so, help me put a number to what the performance cost is. Server is a Dell R510 with dual E5620 CPUs and 8 GB RAM. There are eight 15k 2.5” 600 GB drives (Seagate ST3600057SS) configured in hardware RAID-6 with a single hot spare. RAID controller is a Dell PERC H700 w/512MB cache (Linux sees this as a LSI MegaSAS 9260). OS is CentOS 5.6, home directory partition is ext3, with options “rw,data=journal,usrquota”. I have the HW RAID configured to present two virtual disks to the OS: /dev/sda for the OS (boot, root and swap partitions), and /dev/sdb for a big NFS share: [root@lnxutil1 ~]# parted -s /dev/sda unit s print Model: DELL PERC H700 (scsi) Disk /dev/sda: 134217599s Sector size (logical/physical): 512B/512B Partition Table: msdos Number Start End Size Type File system Flags 1 63s 465884s 465822s primary ext2 boot 2 465885s 134207009s 133741125s primary lvm [root@lnxutil1 ~]# parted -s /dev/sdb unit s print Model: DELL PERC H700 (scsi) Disk /dev/sdb: 5720768639s Sector size (logical/physical): 512B/512B Partition Table: gpt Number Start End Size File system Name Flags 1 34s 5720768606s 5720768573s lvm Edit 1 Using the cfq IO scheduler (default for CentOS 5.6): # cat /sys/block/sd{a,b}/queue/scheduler noop anticipatory deadline [cfq] noop anticipatory deadline [cfq] Chunk size is the same as strip size, right? If so, then 64kB: # /opt/MegaCli -LDInfo -Lall -aALL -NoLog Adapter #0 Number of Virtual Disks: 2 Virtual Disk: 0 (target id: 0) Name:os RAID Level: Primary-6, Secondary-0, RAID Level Qualifier-3 Size:65535MB State: Optimal Stripe Size: 64kB Number Of Drives:7 Span Depth:1 Default Cache Policy: WriteBack, ReadAdaptive, Direct, No Write Cache if Bad BBU Current Cache Policy: WriteThrough, ReadAdaptive, Direct, No Write Cache if Bad BBU Access Policy: Read/Write Disk Cache Policy: Disk's Default Number of Spans: 1 Span: 0 - Number of PDs: 7 ... physical disk info removed for brevity ... Virtual Disk: 1 (target id: 1) Name:share RAID Level: Primary-6, Secondary-0, RAID Level Qualifier-3 Size:2793344MB State: Optimal Stripe Size: 64kB Number Of Drives:7 Span Depth:1 Default Cache Policy: WriteBack, ReadAdaptive, Direct, No Write Cache if Bad BBU Current Cache Policy: WriteThrough, ReadAdaptive, Direct, No Write Cache if Bad BBU Access Policy: Read/Write Disk Cache Policy: Disk's Default Number of Spans: 1 Span: 0 - Number of PDs: 7 If it's not obvious, virtual disk 0 corresponds to /dev/sda, for the OS; virtual disk 1 is /dev/sdb (the exported home directory tree).

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