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  • SQL SERVER - Detecting non-indexed columns but used in WHERE clause

    - by Vadi
    How to detect a column included in WHERE clause but used in indexed? Little Background: Until the time the table has few number of records things will be okay, once it started having millions of records then index should be created for a column which is used in WHERE clauses in stored procs, inline queries etc., Since we have hundreds of stored procs and queries that often gets changed by the devs I wanted to have a automated way of identifying those columns that are used in WHERE clauses but not an index is created. How to do that in SQL SERVER 2008?

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  • using dummy row with NOT NULL to solve DEFAULT NULL

    - by Tony38
    I know having DEFAULT NULLS is not a good practice but I have many optional lookup values which are FK in the system so to solve this issue here is what i am doing: I use NOT NULL for every FK / lookup colunms. I have the first row in every lookup table which is PK id = 1 as a dummy row with just "none" in all the columns. This way I can use NOT NULL in my schema and if needed reference to the none row values PK =1 for FKs which do not have any lookup value. Is this a good design or any other work arounds? EDIT: I have: Neighborhood table Postal table. Every neighborhood has a city, so the FK can be NOT NULL. But not every postal code belongs to a neighborhood. Some do, some don't depending on the country. So if i use NOT NULL for the FK between postal and neighborhood then I will be screwed as there has to be some value entered. So what i am doing in essence is: have a row in every table to be a dummy row just to link the FKs. This way row one in neighborhood table will be: n_id = 1 name =none etc... In postal table I can have: postal_code = 3456A3 FK (city) = Moscow FK (neighborhood_id)=1 as a NOT NULL. If I don't have a dummy row in the neighborhood lookup table then I have to declare FK (neighborhood_id) as a Default null column and store blanks in the table. This is an example but there is a huge number of values which will have blanks then in many tables.

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  • Fact table with multiple facts

    - by Jeff Meatball Yang
    I have a dimension (SiteItem) has two important facts: perUserClicks perBrowserClicks however, within this dimension, I have groups of dimensions based on an attribute column (let's call the groups AboveFoldItems, LeftNavItems, OnTheFlyItems, etc.) each have more facts that are specific to that group: AboveFoldItems: eyeTime, loadTime LeftNavItems: mouseOverTime OnTheFlyItems: doesn't have any extra, but may in the future Is the following fact table schema ok? DateKey SessionKey SiteItemKey perUserClicks perBrowserClicks eyeTime loadTime mouseOverTime It seems a little wasteful since only some columns pertain to some dimension keys (the irrelevant facts are left NULL). But... this seems like it would be a common problem, so there should be a common solution for this, right?

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  • Self-relation messes up contents in fetching

    - by holographix
    Hi folks, I'm dealing with an annoying problem in core data I've got a table named Character, which is made as follows I'm filling the table in various steps: 1) fill the attributes of the table 2) fill the Character Relation (charRel) FYI charRel is defined as follows I'm feeding the contents by pulling the data from an xml, the feeding code is this curStr = [[NSMutableString stringWithString:[curStr stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]]] retain]; NSLog(@"Parsing relation within these keys %@, in order to get'em associated",curStr); NSArray *chunks = [curStr componentsSeparatedByString: @","]; for( NSString *relId in chunks ) { NSLog(@"Associating %@ with id %@",[currentCharacter valueForKey:@"character_id"], relId); NSFetchRequest *request = [[NSFetchRequest alloc] init]; NSPredicate *predicate = [NSPredicate predicateWithFormat:@"character_id == %@", relId]; [request setEntity:[NSEntityDescription entityForName:@"Character" inManagedObjectContext:[self managedObjectContext] ]]; [request setPredicate:predicate]; NSerror *error = nil; NSArray *results = [[self managedObjectContext] executeFetchRequest:request error:&error]; // error handling code if(error != nil) { NSLog(@"[SYMBOL CORRELATION]: retrieving correlated symbol error: %@", [error localizedDescription]); } else if([results count] > 0) { Character *relatedChar = [results objectAtIndex:0]; // grab the first result in the stack, could be done better! [currentCharacter addCharRelObject:relatedChar]; //VICE VERSA RELATIONS NSArray *charRels = [relatedChar valueForKey:@"charRel"]; BOOL alreadyRelated = NO; for(Character *charRel in charRels) { if([[charRel valueForKey:@"character_id"] isEqual:[currentCharacter valueForKey:@"character_id"]]) { alreadyRelated = YES; break; } } if(!alreadyRelated) { NSLog(@"\n\t\trelating %@ with %@", [relatedChar valueForKey:@"character_id"], [currentCharacter valueForKey:@"character_id"]); [relatedChar addCharRelObject:currentCharacter]; } } else { NSLog(@"[SYMBOL CORRELATION]: related symbol was not found! ##SKIPPING-->"); } [request release]; } NSLog(@"\t\t### TOTAL OF REALTIONS FOR ID %@: %d\n%@", [currentCharacter valueForKey:@"character_id"], [[currentCharacter valueForKey:@"charRel"] count], currentCharacter); error = nil; /* SAVE THE CONTEXT */ if (![managedObjectContext save:&error]) { NSLog(@"Whoops, couldn't save the symbol record: %@", [error localizedDescription]); NSArray* detailedErrors = [[error userInfo] objectForKey:NSDetailedErrorsKey]; if(detailedErrors != nil && [detailedErrors count] > 0) { for(NSError* detailedError in detailedErrors) { NSLog(@"\n################\t\tDetailedError: %@\n################", [detailedError userInfo]); } } else { NSLog(@" %@", [error userInfo]); } } at this point when I print out the values of the currentCharacter, everything looks perfect. every relation is in its place. in example in this log we can clearly see that this element has got 3 items in charRel: <Character: 0x5593af0> (entity: Character; id: 0x55938c0 <x-coredata://67288D50-D349-4B19-B7CB-F7AC4671AD61/Character/p86> ; data: { catRel = "<relationship fault: 0x9a29db0 'catRel'>"; charRel = ( "0x9a1f870 <x-coredata://67288D50-D349-4B19-B7CB-F7AC4671AD61/Character/p74>", "0x9a14bd0 <x-coredata://67288D50-D349-4B19-B7CB-F7AC4671AD61/Character/p109>", "0x558ba00 <x-coredata://67288D50-D349-4B19-B7CB-F7AC4671AD61/Character/p5>" ); "character_id" = 254; examplesRel = "<relationship fault: 0x9a29df0 'examplesRel'>"; meaning = "\n Left"; pinyin = "\n zu\U01d2"; "pronunciation_it" = "\n zu\U01d2"; strokenumber = 5; text = "\n \n <p>The most ancient form of this symbol"; unicodevalue = "\n \U5de6"; }) then when I'm in need of retrieving this item I perform an extraction, like this: // at first I get the single Character record NSFetchRequest *request = [[NSFetchRequest alloc] init]; NSError *error; NSPredicate *predicate = [NSPredicate predicateWithFormat:@"character_id == %@", self.char_id ]; [request setEntity:[NSEntityDescription entityForName:@"Character" inManagedObjectContext:_context ]]; [request setPredicate:predicate]; NSArray *fetchedObjs = [_context executeFetchRequest:request error:&error]; when, for instance, I print out in NSLog the contents of charRel NSArray *correlations = [singleCharacter valueForKey:@"charRel"]; NSLog(@"CHARACTER OBJECT \n%@", correlations); I get this Relationship fault for (<NSRelationshipDescription: 0x5568520>), name charRel, isOptional 1, isTransient 0, entity Character, renamingIdentifier charRel, validation predicates (), warnings (), versionHashModifier (null), destination entity Character, inverseRelationship (null), minCount 1, maxCount 99 on 0x6937f00 hope that I made myself clear. this thing is driving me insane, I've googled all over world, but I couldn't find a solution (and this make me think to as issue related to bad coding somehow :P). thank you in advance guys. k

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  • Migrating from hand-written persistence layer to ORM

    - by Sergey Mikhanov
    Hi community, We are currently evaluating options for migrating from hand-written persistence layer to ORM. We have a bunch of legacy persistent objects (~200), that implement simple interface like this: interface JDBC { public long getId(); public void setId(long id); public void retrieve(); public void setDataSource(DataSource ds); } When retrieve() is called, object populates itself by issuing handwritten SQL queries to the connection provided using the ID it received in the setter (this usually is the only parameter to the query). It manages its statements, result sets, etc itself. Some of the objects have special flavors of retrive() method, like retrieveByName(), in this case a different SQL is issued. Queries could be quite complex, we often join several tables to populate the sets representing relations to other objects, sometimes join queries are issued on-demand in the specific getter (lazy loading). So basically, we have implemented most of the ORM's functionality manually. The reason for that was performance. We have very strong requirements for speed, and back in 2005 (when this code was written) performance tests has shown that none of mainstream ORMs were that fast as hand-written SQL. The problems we are facing now that make us think of ORM are: Most of the paths in this code are well-tested and are stable. However, some rarely-used code is prone to result set and connection leaks that are very hard to detect We are currently squeezing some additional performance by adding caching to our persistence layer and it's a huge pain to maintain the cached objects manually in this setup Support of this code when DB schema changes is a big problem. I am looking for an advice on what could be the best alternative for us. As far as I know, ORMs has advanced in last 5 years, so it might be that now there's one that offers an acceptable performance. As I see this issue, we need to address those points: Find some way to reuse at least some of the written SQL to express mappings Have the possibility to issue native SQL queries without the necessity to manually decompose their results (i.e. avoid manual rs.getInt(42) as they are very sensitive to schema changes) Add a non-intrusive caching layer Keep the performance figures. Is there any ORM framework you could recommend with regards to that?

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  • Higher speed options for executing very large (20 GB) .sql file in MySQL

    - by Jonogan
    My firm was delivered a 20+ GB .sql file in reponse to a request for data from the gov't. I don't have many options for getting the data in a different format, so I need options for how to import it in a reasonable amount of time. I'm running it on a high end server (Win 2008 64bit, MySQL 5.1) using Navicat's batch execution tool. It's been running for 14 hours and shows no signs of being near completion. Does anyone know of any higher speed options for such a transaction? Or is this what I should expect given the large file size? Thanks

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  • MySQL foreign key constraint disappearing

    - by Bramjam
    This is my table: /* oefenreeks leerplan */ CREATE TABLE leerplan_oefenreeks ( leerplan_oefenreeks_id INT PRIMARY KEY AUTO_INCREMENT NOT NULL, leerplan_id INT NOT NULL, oefenreeks_id INT NOT NULL, plaats INT NOT NULL ); /* fk */ ALTER TABLE leerplan_oefenreeks ADD CONSTRAINT fk_leerp_oefenr_leerplan FOREIGN KEY(leerplan_id) REFERENCES leerplan (leerplan_id) ON DELETE CASCADE; ALTER TABLE leerplan_oefenreeks ADD CONSTRAINT fk_leerp_oefenr_oefenreeks FOREIGN KEY(oefenreeks_id) REFERENCES oefenreeks (oefenreeks_id) ON DELETE CASCADE; /* when I execute the nexline, my fk_leerp_oefenr_leerplan constraint vanishes/disappears*/ ALTER TABLE leerplan_oefenreeks ADD CONSTRAINT un_leerp_oefenr UNIQUE(leerplan_id, oefenreeks_id); ALTER TABLE leerplan_oefenreeks ADD CONSTRAINT un_leerp_oefenr_plaats UNIQUE(leerplan_id, plaats); When I go and check only 3 constraints exist. fk_leerp_oefenr_leerplan disappears. I don't understand why this happens.

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  • Detecting changes between rows with same ID

    - by Noah
    I have a table containing some names and their associated ID, along with a snapshot: snapshot, id, name I need to identify when a name has changed for an id between snapshots. For example, in the following data: 1, 0, 'MOUSE_SPEED' 1, 1, 'MOUSE_POS' 1, 2, 'KEYBOARD_STATE' 2, 0, 'MOUSE_BUTTONS' 2, 1, 'MOUSE_POS' 2, 2, 'KEYBOARD_STATE' ...the meaning of id 0 changed with snapshot 2, but the others remained the same. I'd like to construct a query that (ideally) returns: 1, 0, 'MOUSE_SPEED' 2, 0, 'MOUSE_BUTTONS' I am using PostgreSQL v8.4.2.

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  • querying larg text file containing JSON objects.

    - by Maciek Sawicki
    Hi, I have few Gigabytes text file in format: {"user_ip":"x.x.x.x", "action_type":"xxx", "action_data":{"some_key":"some_value"...},...} each entry is one line. First I would like to easily find entries for given ip. This part is easy because I can use grep for example. However even for this I would like to find better solution because I would like to get response as fast as possible. Next part is more complicated because I would like to find entries from selected ip and of selected type and with particular value of some_key in action_data. Probably I would have to convert this file to SQL db (probably SQLite, because it will be desktop APP), but I would ask if there are exists better solutions?

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  • Reading directly from the Doctrine Searchable index table

    - by phidah
    I've got a Doctrine table with the Searchable behavior enabled. Whenever a record is created, an index is made in another table. I have a model called Entry and the behavior automatically created the table entry_index. My question now is: How can I - without using the search(...) methods of my model use the data from this table? I want to create a tag cloud of the words most used, and the data in the index table is exactly what I need.

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  • Syntax Error with MySQL 5.1 Server

    - by Mr.Z
    I am trying to connect to a server remotely using the command line client window. I am using MySQL 5.1 and I do not know why I am getting syntax error. If you can help me, that would be much appreciated. username as user password as pass hostname as example.com I have tried: mysql> -u user -h example.com -p ; mysql> -h example.com -u user -p ; I have looked at the reference manual and other verisons of remote connection with Server 5.1 but I can't see the syntax error.

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  • Syntax for "RETURNING" clause in Mysql PDO

    - by dmontain
    I'm trying to add a record, and at the same time return the id of that record added. I read it's possible to do it with a RETURNING clause. $stmt->prepare("INSERT INTO tablename (field1, field2) VALUES (:value1, :value2) RETURNING id"); but the insertion fails when I add RETURNING. There is an auto-incremented field called id in the table being added to. Can someone see anything wrong with my syntax? or maybe PDO does not support RETURNING?

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  • MSSQL 2005: Rename DB Server Instance Name?

    - by Code Sherpa
    Hi, Can somebody tell me how to rename the DB server instance name and a DB name in MSSQL 2005? Right Now I Have SERVER/OLDNAME -- oldnameDB I want to change the server instance and also change the db name. I have tried: EXEC sp_renamedb 'oldName', 'newName' and that has changed the dbname as it appers in the tree directory. But, when I do "select @@servername" it is the old name. Also, the MDF and LDF files are still the old name. How do change instance and db names as a clean sweep across the server? Thanks.

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  • Creating a Group of Groups in Django

    - by Greg
    I'm creating my own Group model; I'm not referring to the builtin Group model. I want each hroup to be a member of another group (it's parent), but there is the one "top" group that doesn't have a parent group. The admin interface won't let me create a group without entering a parent. I get the error personnel_group.parent_id may not be NULL. My Group model looks like this: class Group(models.Model): name = models.CharField(max_length=50) parent = models.ForeignKey('self', blank=True, null=True) order = models.IntegerField() icon = models.ImageField(upload_to='groups', blank=True, null=True) description = models.TextField(blank=True, null=True) How can I accomplish this? Thanks.

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  • Sqlite and Python -- return a dictionary using fetchone()?

    - by AndrewO
    I'm using sqlite3 in python 2.5. I've created a table that looks like this: create table votes ( bill text, senator_id text, vote text) I'm accessing it with something like this: v_cur.execute("select * from votes") row = v_cur.fetchone() bill = row[0] senator_id = row[1] vote = row[2] What I'd like to be able to do is have fetchone (or some other method) return a dictionary, rather than a list, so that I can refer to the field by name rather than position. For example: bill = row['bill'] senator_id = row['senator_id'] vote = row['vote'] I know you can do this with MySQL, but does anyone know how to do it with SQLite? Thanks!!!

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  • Select where and where not

    - by Simon
    I have a table containing lessons that I called "cours" (french) and I have several cours inside and I have linked them to students with a table between them to see if they go to the lessons or not. I would like to return data with the SELECT and the data that are NOT select. So, If one student follow 3 courses of 5, I would like to return the 3 courses that he follow and the 2 courses that he doesn't follow. Is there a way to do it ?

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  • Using NULLs in matchup table

    - by TomWilsonFL
    I am working on the accounting portion of a reservation system (think limo company). In the system there are multiple objects that can either be paid or submit a payment. I am tracking all of these "transactions" in three tables called: tx, tx_cc, and tx_ch. tx generates a new tx_id (for transaction ID) and keeps the information about amount, validity, etc. Tx_cc and tx_ch keep the information about the credit card or check used, respectively, which link to other tables (credit_card and bank_account among others). This seems fairly normalized to me, no? Now here is my problem: The payment transaction can take place for a myriad of reasons. Either a reservation is being paid for, a travel agent that booked a reservation is being paid, a driver is being paid, etc. This results in multiple tables, one for each of the entities: agent_tx, driver_tx, reservation_tx, etc. They look like this: CREATE TABLE IF NOT EXISTS `driver_tx` ( `tx_id` int(10) unsigned zerofill NOT NULL, `driver_id` int(11) NOT NULL, `reservation_id` int(11) default NULL, `reservation_item_id` int(11) default NULL, PRIMARY KEY (`tx_id`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8; Now this transaction is for a driver, but could be applied to an individual item on the reservation or the entire reservation overall. Therefore I demand either reservation_id OR reservation_item_id to be null. In the future there may be other things which a driver is paid for, which I would also add to this table, defaulting to null. What is the rule on this? Opinion? Obviously I could break this out into MANY three column tables, but the amount of OUTER JOINing needed seems outrageous. Your input is appreciated. Peace, Tom

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  • PHP mySQL - replace some string inside string

    - by apis17
    i want to replace ALL comma , into ,<space> in all address table in my mysql table. For example, +----------------+----------------+ | Name | Address | +----------------+----------------+ | Someone name | A1,Street Name | +----------------+----------------+ Into +----------------+----------------+ | Name | Address | +----------------+----------------+ | Someone name | A1, Street Name| +----------------+----------------+ Thanks in advance.

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  • Join Where Rows Don't Exist or Where Criteria Matches...?

    - by Greg
    I'm trying to write a query to tell me which orders have valid promocodes. Promocodes are only valid between certain dates and optionally certain packages. I'm having trouble even explaining how this works (see psudo-ish code below) but basically if there are packages associated with a promocode then the order has to have one of those packages and be within a valid date range otherwise it just has to be in a valid date range. The whole "if PrmoPackage rows exist" thing is really throwing me off and I feel like I should be able to do this without a whole bunch of Unions. (I'm not even sure if that would make it easier at this point...) Anybody have any ideas for the query? if `OrderPromoCode` = `PromoCode` then if `OrderTimestamp` is between `PromoStartTimestamp` and `PromoEndTimestamp` then if `PromoCode` has packages associated with it //yes then if `PackageID` is one of the specified packages //yes code is valid //no invalid //no code is valid Order: OrderID* | OrderTimestamp | PackageID | OrderPromoCode 1 | 1/2/11 | 1 | ABC 2 | 1/3/11 | 2 | ABC 3 | 3/2/11 | 2 | DEF 4 | 4/2/11 | 3 | GHI Promo: PromoCode* | PromoStartTimestamp* | PromoEndTimestamp* ABC | 1/1/11 | 2/1/11 ABC | 3/1/11 | 4/1/11 DEF | 1/1/11 | 1/11/13 GHI | 1/1/11 | 1/11/13 PromoPackage: PromoCode* | PromoStartTimestamp* | PromoEndTimestamp* | PackageID* ABC | 1/1/11 | 2/1/11 | 1 ABC | 1/1/11 | 2/1/11 | 3 GHI | 1/1/11 | 1/11/13 | 1 Desired Result: OrderID | IsPromoCodeValid 1 | 1 2 | 0 3 | 1 4 | 0

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