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  • Fastest way to store/retrieve a dictionary - SQL, text file...?

    - by AP257
    Hi all, This is a really really super dumb question, so I apologise, but I'd be grateful for some advice. I've got a text file of words and word frequencies. It's very large - theoretically we're talking millions of rows. I just want to retrieve values from the file, and do it as quickly and efficiently as possible (for a web app, in Django). My question is: what is the best way to store and retrieve the values? Should import them into SQL? Or keep the file and use grep? Or put them into a JSON dictionary...? Or some other way? Sorry for the dumb question, would be very grateful for advice!

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  • Can't fill a column of NULLs with actual values by making an association to the proper values in the

    - by UkraineTrain
    I have a table with separate columns for months, days and a varchar column for 6 hour increments for each day ('12AM', '6AM', '12PM', '6PM'). There's also a column that's supposed to have calculated numeric values for each of those 6 hour increments. These calculated values come from some reference table. This reference table contains values for each day for several months broken down by hour where each hour has its own column. So, basically, I have to add the values for each 6 hour increment. I have no idea how to associate the correct values in the reference table to those 6 hour increments. I will really appreciate any help on this.

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  • make db connection persistent throught zend framework

    - by kamikaze_pilot
    I'm using zend framework. currently everytime I need to use the db I go ahead and connect to the DB: function connect(){ $connParams = array("host" => $host, "port" => $port, "username" => $username, "password" => $password, "dbname" => $dbname); $db = new Zend_Db_Adapter_Pdo_Mysql($connParams); return $db } so I would just call the connect() function everytime I need to use the db My question is...suppose I want to reuse $db everywhere in my site and only connect once in the very initial stage of the site load and then close the connection right before the site gets sent to the user, what would be the best practice to accomplish this? Which file in Zend should I save $db in, what method should I use to save it (global variable?), and which file should I do the connection closing in?

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  • Fastest way to do a weighted tag search in SQL Server

    - by Hasan Khan
    My table is as follows ObjectID bigint Tag nvarchar(50) Weight float Type tinyint I want to get search for all objects that has tags 'big' or 'large' I want the objectid in order of sum of weights (so objects having both the tags will be on top) select objectid, row_number() over (order by sum(weight) desc) as rowid from tags where tag in ('big', 'large') and type=0 group by objectid the reason for row_number() is that i want paging over results. The query in its current form is very slow, takes a minute to execute over 16 million tags. What should I do to make it faster? I have a non clustered index (objectid, tag, type) Any suggestions?

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  • No operations allowed after statement closed issue

    - by Washu
    I have the next methods in my singleton to execute the JDBC connections public void openDB() throws ClassNotFoundException, IllegalAccessException, InstantiationException, SQLException { Class.forName("com.mysql.jdbc.Driver").newInstance(); String url = "jdbc:mysql://localhost/mbpe_peru";//mydb conn = DriverManager.getConnection(url, "root", "admin"); st = conn.createStatement(); } public void sendQuery(String query) throws SQLException { st.executeUpdate(query); } public void closeDB() throws SQLException { st.close(); conn.close(); } And I'm having a problem in a void where i have to call this twice. private void jButton1ActionPerformed(ActionEvent evt) { Main.getInstance().openDB(); Main.getInstance().sendQuery("call insertEntry('"+EntryID()+"','"+SupplierID()+"');"); Main.getInstance().closeDB(); Main.getInstance().openDB(); for(int i=0;i<dataBox.length;i++){ Main.getInstance().sendQuery("call insertCount('"+EntryID()+"','"+SupplierID()+"','"+BoxID()+"'); Main.getInstance().closeDB(); } } I have already tried to keep the connection open and send the 2 querys and after that closed and it didnt work... The only way it worked was to not use the methods, declare the commands for the connection and use different variables for the connection and the statement. I thought that if i close the Connecion and the Statement I could use the variable once again since is a method but I'm not able to. Is there any way to solve this using my methods for the JDBC connection?

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  • Synchronizing MySQL databases

    - by Wasim
    Hi all, I have a maintanance problem synchronizing my MySQL data bases . These are the databases I have : My development DB : Here I make my curret development changes . Staging DB : I need to make all the changes I did in the development on it before using , currently I hold migration scripts for structure and data. Production DB : A production environment . Have to do exacly the same as the staging . My problem , is sync. the structure , and some of the data. This is really a very hard work to maintaine. Is there any technics , tools to do with MySQL . What is replication , is it good for my situation , how to use it . Thanks in advance ...

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  • Can't create a MySQL query that generates 4 rows for each row in the table it references.

    - by UkraineTrain
    I need to create a MySQL query that generates 4 rows for each row in the table it references. I need some of the information in those rows to repeat and some to be different. In the table each row stands for one day. I need to break the day up in 6 hour increments, hence the four rows for each entry. I need to create one column which for each day will have '12AM', '6AM', '12PM', and '6PM' values and another column will have the corresponding numeric values calculated for those entries. Thanks a lot in advance and I will really appreciate any help on this.

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  • Hosting an Access DB

    - by Mitciv
    Hey, So I'm inexperienced in hosting DB's and I've always had the luxury of someone else getting the db setup. I was going to help a friend out with getting a webpage setup, I've got experience in Asp.Net MVC so I'm going with that. They want to setup a search page to query a db and display the results. My question I have is in getting the DB setup and hosted. They currently just have the Access DB on a local computer. There is basically only one table that would need to be queried for the search. What is the best approach to getting this table/db accessible? They would like to keep the main copy of the db on the local machine, so copying the entire db over to the hosted site would be time consuming, could the lone table needed be solely copied to the host? Should I try to convince them to make changes on the hosted db and just make copies of that for their local machines? Any suggestions are welcome, Again I'm a total noob when it comes to hosting databases. Thanks

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  • Using a variable derived from a drop-down list as the column name in a select statement ... Access DB

    - by user1459698
    I'm working with the world's worst DB that was already here so don't blame me for that. So, here's what I have so far ... module = txtModule.value presstype = txtPressType.value SQL_query = "SELECT * FROM tbl_spareparts WHERE '"& module &"' <> '""' AND '"& module &"' = '"& presstype &"' AND Manufacturer = '"& txtsrch.value &"' ORDER BY SAP_Part_No" Set rsData = conn.Execute(SQL_query) This brings up the following SQL statement: SELECT * FROM tbl_spareparts WHERE 'Banyan_Module' <> '"' AND 'Banyan_Module' = 'PB' AND Manufacturer = 'Tester' ORDER BY SAP_Part_No Is there any way I can use the module variable as a column name - obviously the ''s around the column name are causing an error. This is really bothering me. BTW, I'm writing this in VBScript inside a .HTA application page as it has to run locally on tech PCs. Thanks. R.

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  • Efficient update of SQLite table with many records

    - by blackrim
    I am trying to use sqlite (sqlite3) for a project to store hundreds of thousands of records (would like sqlite so users of the program don't have to run a [my]sql server). I have to update hundreds of thousands of records sometimes to enter left right values (they are hierarchical), but have found the standard update table set left_value = 4, right_value = 5 where id = 12340; to be very slow. I have tried surrounding every thousand or so with begin; .... update... update table set left_value = 4, right_value = 5 where id = 12340; update... .... commit; but again, very slow. Odd, because when I populate it with a few hundred thousand (with inserts), it finishes in seconds. I am currently trying to test the speed in python (the slowness is at the command line and python) before I move it to the C++ implementation, but right now this is way to slow and I need to find a new solution unless I am doing something wrong. Thoughts? (would take open source alternative to SQLite that is portable as well)

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  • sqlserver how to set job priority

    - by Buzz
    Is there any way to set one job priority higher then other, In my case there are two jobs those are working on same set of tables,first JOB-A which is running every 12 hr and other JOB-B is every 10 minutes , i think at some time when they run simultaneously JOB-B is getting in to deadlock and get failed, i google the topic and found sqlgoverner is helpful in such cases does anyone know how to resolve?

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  • Are comonads a good fit for modeling the Wumpus world?

    - by Tim Stewart
    I'm trying to find some practical applications of a comonad and I thought I'd try to see if I could represent the classical Wumpus world as a comonad. I'd like to use this code to allow the Wumpus to move left and right through the world and clean up dirty tiles and avoid pits. It seems that the only comonad function that's useful is extract (to get the current tile) and that moving around and cleaning tiles would not use be able to make use of extend or duplicate. I'm not sure comonads are a good fit but I've seen a talk (Dominic Orchard: A Notation for Comonads) where comonads were used to model a cursor in a two-dimensional matrix. If a comonad is a good way of representing the Wumpus world, could you please show where my code is wrong? If it's wrong, could you please suggest a simple application of comonads? module Wumpus where -- Incomplete model of a world inhabited by a Wumpus who likes a nice -- tidy world but does not like falling in pits. import Control.Comonad -- The Wumpus world is made up of tiles that can be in one of three -- states. data Tile = Clean | Dirty | Pit deriving (Show, Eq) -- The Wumpus world is a one dimensional array partitioned into three -- values: the tiles to the left of the Wumpus, the tile occupied by -- the Wumpus, and the tiles to the right of the Wumpus. data World a = World [a] a [a] deriving (Show, Eq) -- Applies a function to every tile in the world instance Functor World where fmap f (World as b cs) = World (fmap f as) (f b) (fmap f cs) -- The Wumpus world is a Comonad instance Comonad World where -- get the part of the world the Wumpus currently occupies extract (World _ b _) = b -- not sure what this means in the Wumpus world. This type checks -- but does not make sense to me. extend f w@(World as b cs) = World (map world as) (f w) (map world cs) where world v = f (World [] v []) -- returns a world in which the Wumpus has either 1) moved one tile to -- the left or 2) stayed in the same place if the Wumpus could not move -- to the left. moveLeft :: World a -> World a moveLeft w@(World [] _ _) = w moveLeft (World as b cs) = World (init as) (last as) (b:cs) -- returns a world in which the Wumpus has either 1) moved one tile to -- the right or 2) stayed in the same place if the Wumpus could not move -- to the right. moveRight :: World a -> World a moveRight w@(World _ _ []) = w moveRight (World as b cs) = World (as ++ [b]) (head cs) (tail cs) initWorld = World [Dirty, Clean, Dirty] Dirty [Clean, Dirty, Pit] -- cleans the current tile cleanTile :: Tile -> Tile cleanTile Dirty = Clean cleanTile t = t Thanks!

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  • how to get transform a local image to a web accessable image

    - by hguser
    Hi: Generally,if we want to display a image in the web page,we give the uri of the image resource like: http://host:port/image/xxx.jpg. Now,there are some images in my file system,and I save its absolute path in the db. Like this; id name address image 1 xxxx xxxx C:/images/xxx.jpg Now if the entity is retrived,its image should be displayed in the page. How to make it? What I thought is copy the image under the web server dir,then build its url,then the page can render it. But I wonder if this is a good idea? Is there any other way?

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  • Mysql- "FLUSH TABLES WITH READ LOCK" started automatically

    - by ming yeow
    I would like to understand how this happened. I was running a query that would take a long time, but should not lock up any table. However, my dbs were practically down - it seems like it was being locked up by "FLUSH TABLES WITH READ LOCK" 03:21:31 select type_id, count(*) from guid_target_infos group by type_id 02:38:11 select type_id, count(*) from guid_infos group by type_id 02:24:29 FLUSH TABLES WITH READ LOCK But i did not start this command. can someone tell me why it was started automatically?

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  • Solr; What does this mean?

    - by Camran
    At the end of the README.txt file which is located in the example directory under solr, I find this line: NOTE: This Solr example server references SolrCell jars outside of the server directory with statements in the solrconfig.xml. If you make a copy of this example server and wish to use the ExtractingRequestHandler (SolrCell), you will need to copy the required jars into solr/lib or update the paths to the jars in your solrconfig.xml What does this mean? Do I have to make some adjustment before uploading solr to my server? Also, if you know, what is Solr-nightly:s difference to regular solr? The tutorial states "solr-nightly.zip" but on their download section I cant find it.

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  • How to load the SQL data into several ComboBox easily, am i doing the correctly or is there another way

    - by Dominic Deepan.d
    I have a Combobox to fill the data for City, State and PinCode these combobox is dopdown list and the user will pick it. and it loads once the form opens. Here is the CODE: /// CODE TO BRING A DATA FROM SQL INTO THE FORM DROP LIST /// To fill the sates from States Table cn = new SqlConnection(@"Data Source=Nick-PC\SQLEXPRESS;Initial Catalog=AutoDB;Integrated Security=True"); cmd= new SqlCommand("select * from TblState",cn); cn.Open(); SqlDataReader dr; try { dr = cmd.ExecuteReader(); while (dr.Read()) { SelectState.Items.Add(dr["State"].ToString()); } } catch (Exception ex) { MessageBox.Show(ex.Message); } finally { cn.Close(); } //To fill the Cities from City Table cn1 = new SqlConnection(@"Data Source=Nick-PC\SQLEXPRESS;Initial Catalog=AutoDB;Integrated Security=True"); cmd1 = new SqlCommand("SELECT * FROM TblCity", cn); cn.Open(); SqlDataReader ds; try { ds = cmd1.ExecuteReader(); while (ds.Read()) { SelectCity.Items.Add(ds["City"].ToString()); } } catch (Exception ex) { MessageBox.Show(ex.Message); } finally { cn1.Close(); } // To fill the Data in the Pincode from the City Table cn2 = new SqlConnection(@"Data Source=Nick-PC\SQLEXPRESS;Initial Catalog=AutoDB;Integrated Security=True"); cmd2 = new SqlCommand("SELECT (Pincode) FROM TblCity ", cn2); cn2.Open(); SqlDataReader dm; try { dm = cmd2.ExecuteReader(); while (dm.Read()) { SelectPinCode.Items.Add(dm["Pincode"].ToString()); } } catch (Exception ex) { MessageBox.Show(ex.Message); } finally { cn2.Close(); } its kinda Big, i am doing the same steps for all the combo-box, but is there a way i can merge it in a simple way.

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  • How to undo SQL changes using installer

    - by Sunil Agarwal
    I have installer to install procedures, scripts, views, etc in SQL server 2005/2008. Now I want to add a condition in the installer like if there is any error while installing, I want to undo all the changes done in SQL server. I tried to store the procedures, views, etc which I am changing while installing and reverting them back if I get any error. But am not able to do it the way I want. Can someone guide me if he had done the same thing? To specify I am using WIX installer. Also if someone has tried SMO, it will be of great help.

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  • Fluent nHibernate - How to map a non-key column on a junction table?

    - by The Matt
    Taking an example that is provided on the Fluent nHibernate website, I need to extend it slightly: I need to add a 'Quantity' column to the StoreProduct table. How would I map this using nHibernate? An example mapping is provided for the given scenario above, but I'm not sure how I would get the Quantity column to map to a property on the Product class: public class StoreMap : ClassMap<Store> { public StoreMap() { Id(x => x.Id); Map(x => x.Name); HasMany(x => x.Employee) .Inverse() .Cascade.All(); HasManyToMany(x => x.Products) .Cascade.All() .Table("StoreProduct"); } }

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  • MySQL multiple dependent subqueries, painfully slow

    - by matt80
    I have a working query that retrieves the data that I need, but unfortunately it is painfully slow (runs over 3 minutes). I have indexes in place, but I think the problem is the multiple dependent subqueries. I've been trying to rewrite the query using joins but I can't seem to get it to work. Any help would be greatly appreciated. The tables: Basically, I have 2 tables. The first (prices) holds the prices of items in a store. Each row is the price of an item that day, and new rows are added every day with an updated price. The second table (watches_US) holds the item information (name, description, etc). CREATE TABLE `prices` ( `prices_id` int(11) NOT NULL auto_increment, `prices_locale` enum('CA','DE','FR','JP','UK','US') NOT NULL default 'US', `prices_watches_ID` char(10) NOT NULL, `prices_date` datetime NOT NULL, `prices_am` varchar(10) default NULL, `prices_new` varchar(10) default NULL, `prices_used` varchar(10) default NULL, PRIMARY KEY (`prices_id`), KEY `prices_am` (`prices_am`), KEY `prices_locale` (`prices_locale`), KEY `prices_watches_ID` (`prices_watches_ID`), KEY `prices_date` (`prices_date`) ) ENGINE=MyISAM DEFAULT CHARSET=utf8 AUTO_INCREMENT=61764 ; CREATE TABLE `watches_US` ( `watches_ID` char(10) NOT NULL, `watches_date_added` datetime NOT NULL, `watches_last_update` datetime default NULL, `watches_title` varchar(255) default NULL, `watches_small_image_height` int(11) default NULL, `watches_small_image_width` int(11) default NULL, `watches_description` text, PRIMARY KEY (`watches_ID`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8; The query retrieves the last 10 prices changes over a period of 30 hours, ordered by the size of the price change. So I have subqueries to get the newest price, the oldest price within 30 hours, and then to calculate the price change. Here's the query: SELECT watches_US.*, prices.*, watches_US.watches_ID as current_ID, ( SELECT prices_am FROM prices WHERE prices_watches_ID = current_ID AND prices_locale = 'US' ORDER BY prices_date DESC LIMIT 1 ) as new_price, ( SELECT prices_date FROM prices WHERE prices_watches_ID = current_ID AND prices_locale = 'US' ORDER BY prices_date DESC LIMIT 1 ) as new_price_date, ( SELECT prices_am FROM prices WHERE ( prices_watches_ID = current_ID AND prices_locale = 'US') AND ( prices_date >= DATE_SUB(new_price_date,INTERVAL 30 HOUR) ) ORDER BY prices_date ASC LIMIT 1 ) as old_price, ( SELECT ROUND(((new_price - old_price)/old_price)*100,2) ) as percent_change, ( SELECT (new_price - old_price) ) as absolute_change FROM watches_US LEFT OUTER JOIN prices ON prices.prices_watches_ID = watches_US.watches_ID WHERE ( prices_locale = 'US' ) AND ( prices_am IS NOT NULL ) AND ( prices_am != '' ) HAVING ( old_price IS NOT NULL ) AND ( old_price != 0 ) AND ( old_price != '' ) AND ( absolute_change < 0 ) AND ( prices.prices_date = new_price_date ) ORDER BY absolute_change ASC LIMIT 10 How would I rewrite this to use joins instead, or otherwise optimize this so it doesn't take over 3 minutes to get a result? Any help would be greatly appreciated! Thank you kindly.

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