An acronym for "Structured Query Language" (it's not the name of a specific DBMS product), SQL can be used in relational database management systems (RDBMS) to query, update, delete, and insert data as well as modify the structure of the database. It can also be used to manage schemas and data ...

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Storing date as integer (numeric), what are the advantages

Question 1 I am working with a system where date is stored as integer (actual numeric(8,0)) and I have noticed that other systems also store date as int such as cisco in this thread. Example ...
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SQL Server - Multiple running totals

I've got a base table with transactions and I need to create a table with running totals. I need them to be per account and and also have a few running totals for each account (depending on the ...
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How do I show the binlog_format on a MySQL server?

How do I show the binlog_format on a MySQL server? And if I dont like it how do I set it to XX permanently? Where XX is STATEMENT, ROW or MIXED.
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How to keep history of SQL Server stored procedure revisions

Note: I am not asking about full version control. Is there any way automatically to keep a history of stored procedures on SQL Server. Similar to how Google Docs automatically keeps a history of ...
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Non-Clustered Indexes - keys and nonkeys

I just want to make sure I'm on the right track with these concepts, so any feedback would be greatly appreciated. Here's my theory from the query I've just optimised, through a process of trial and ...
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overstating field size in database design

I have some fields for my tables that are strings and at the moment, most of the field size have pretty high character limits. For instance, 100 char for the street name. Is there a penalty for using ...
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Deadlock error isn't returning the deadlock SQL

Transaction (Process ID) was deadlocked on lock resources with another process and has been chosen as the deadlock victim. Rerun the transaction. I am getting this error randomly when one of my ...
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What are the alternatives for an ORDER BY clause in a View?

This question just had to be in this site :) ORDER BY is forbidden to use in a view, as I understood because of the possibility for multiple order by's when using this view. I know that there are ...
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Oracle: How do I query a Hierarchical table?

Background This is for the construction of some views we'll be using for reporting. I have an table of locations, the key fields being "location" and "parent". The structure that these two fields ...
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How can I optimize this MySQL query further?

I have a query that is taking a particularly long time to run (15+ seconds) and it is only getting worse with time as my dataset grows. I have optimized this in the past, and have added indices, ...
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What is the best way to find out how many records do not have a proper phone number in SQL Server?

I have a field that people historically could use to freely supply a value. I need to identify the records which do not have an appropriate value so I can clean them. I've been looking around in SSIS ...
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function hangs with null case operation

I created a function that accepts a start and end date, with the end date being optional. I then wrote a CASE in the filter to use the start date if no end date is passed. CASE WHEN @dateEnd IS NULL ...
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Where can I find the SQL standard document?

Where can I find a legal copy of the ISO SQL 2008 standard?
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How to boost performance of virgin queries in MS SQL Server?

I have ASP.NET web site that does it's own independent caching of data and data does not change for long periods of time, so it does not need to query SQL Server second time with same query. I need to ...
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Create View in specified database with dynamic sql?

I am writting a dynamic sql to drop and create view in different database. So I wrote: set @CreateViewStatement = ' USE ['+ @DB +']; CREATE VIEW ...
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Is there a way to programmatically script all objects associated with a given table?

I know that in SQL management studio I can right click a table/trigger/key and script object as.... Is there a way to do this programmatically, given an object's name? If so, is there a way to find ...
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SQL Server 2008 and extended properties [closed]

In SQL Server, what do you guys use extended properties for? Some articles and blogs are suggesting they be used for self-documentation of the database and its objects but I can't see this being used ...
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Subqueries' aliases same as main queries' aliases

I have an SQL query whose aliases are the same as some of its subquery's aliases. For example: select * from ROOM r where ... ( select * from ROAD r ...
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Deadlock when update different rows with non-clustered index

I'm solving a deadlocking issue while I noticed the lock behavior is different when I use clustered and non-clustered index on the id field. The deadlock issue seems to be solved if clusted index or ...
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How export a sql server 2008 diagram to PDF filetype?

I want to have a export from my database diagram to PDF or image types.How can I do this? I worked with sql server 2008 R2.
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SQL Server query slow when paginated

I am seeing some strange behaviour with the following T-SQL query in SQL Server 2012: select Id FROM dbo.Person WHERE CONTAINS(Name, '"John" AND "Smith"') order by Name Executing this query alone ...
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Table not getting created under dbo schema

When creating tables in SSMS, I've realized that if you execute the following statement: CREATE TABLE [tableName]; the table will be created under your own schema (and not dbo). So in order to ...
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How to delete a procedure which name is ambigous?

I am using informix... I dont know how i did it, but there are two procedures with the same name in my database. When i try to remove them with a DROP PROCEDURE myProc; then i get a error message ...
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When should indexes be dropped and recreated?

We are constructing a data warehouse that initially will be 1 TB and will grow around 20gigs every month. For certain tables we are doing daily ETL processes and others we are doing weekly/monthly. ...
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Is there an execution difference between a JOIN condition and a WHERE condition?

Is there a performance difference between these two example queries? Query 1: select count(*) from table1 a join table2 b on b.key_col=a.key_col where b.tag = 'Y' Query 2; select ...
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What are the trade offs for incrementing ids vs. fulltext keys for foreign key designs?

In a lot of relational database designs there are fields that are referenced in other tables. For example consider a user table with a unique username and a second table storing address data. One ...
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Mirroring the Distributor

Has anyone had success with mirroring the distribution database? We have a dedicated server as a Distributor. It handles all our push replication from prod to reporting. We'd like to build an ...
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LNNVL Justification

LNNVL is an oracle built in function that returns TRUE for conditions evaluating to FALSE or UNKNOWN, and returns FALSE for conditions evaluating to TRUE. My question is what would be the benefit of ...
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Why are simple SELECTs on InnoDB 100x slower than on MyISAM?

I have quite an annoying problem. I want to use INNODB as my main database engine and give up on MyISAM as I need the former for using galera-cluster for redundancy. I copied (description follows) ...
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859 views

What are the security implications of sp_executesql?

By default, in SQL Server, the [public] role has EXECUTE rights on sp_executesql. However, I've inherited a database server where the previous DBA has revoked the EXECUTE right on sp_executesql. As ...
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How does using separate schemas affect SQL Server 2008 performance?

I want to use separate schemas for objects with different purposes in our SQL Server 2008 database. Right now we use a fairly mind-numbing naming convention to indicate the purpose of a table or ...
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SQL Server's READ COMMITTED SNAPSHOT vs SNAPSHOT

I was researching the differences between SQL Server's READ COMMITTED SNAPSHOT and SNAPSHOT isolation levels and came across the following resource: Choosing Row Versioning-based Isolation Levels ...
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Handling time zones in data mart/warehouse

We are starting to design the building blocks of a data mart/warehouse and we need to be able to support all time zones (our clients are from all over the world). From reading discussions online (and ...
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Database design: Dividing multiple identical tables, good or bad?

I am very new at SQL and databases in general. I only use them for the occasional homework so I haven't even tried to master them. I have seats at a theater, the seats are divided into 4 main areas ...
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SQL Database Structure for RESTful API

I am creating a RESTful API. I am struggling to decide on the best way to design my database tables around my resources. Initially, I though a table per resource would be a good way to go, but I'm ...
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A good SQL sniffer

Can anyone point me to a good SQL sniffer where I can watch the SQL commands that run against my database in real time? If it's free, that would be great.
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Do SQL Server stored procedures cache data results?

I have heard this from friends, but I never investigated whether this is true. Is it true that the data results of an executed query are stored in cache? I mean, if I have a stored procedure like : ...
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Does disconnecting the network stop a query?

I recently executed an update query against 100,000 records. I realized I'd made a mistake while the query was running and quickly unplugged the network cable. Does the update query stop ...
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How can I use a default value in a Select query in PostgreSQL?

I would like to use a default value for a column that should be used if no rows is returned. Is that possible in PostgreSQL? How can I do it? Or is there any other way I can solve this? E.g. ...
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What does the term “projection” refer to in an SQL query (or view definition)

In Oracle's document The Query Optimizer, under View Merging, I found the following information The view merging optimization applies to views that contain only selections, projections, and ...
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More Databases Per Sql Server 2005 Instance

Our company currently hosts about 400 databases per SQL Server 2005 instance. 500-600 databases and we see performance start to deteriorate. Database size ranges from 50mb to 40-60gb in the extreme, ...
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Is there a standard implementation of a Users Database?

I need to implement basic personalized user functionality for my website. Is there a standard structure for databases of this type? Like is it common practice to have all user info and data in a ...
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How to find parent rows that have indentical sets of child rows?

Suppose I have structure like this: Recipes Table: RecipeID Name Description RecipeIngredients Table: RecipeID IngredientID Quantity UOM What are some good ways for ...
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What is the purpose of the USING parameter in SQL?

Working with some code on a standard MySQL database, and I came across this statement: SELECT * FROM foo LEFT JOIN bar USING ('bar_id') WHERE foo_id = 1 What's throwing me is: what is USING for, ...
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Where to start with Oracle?

This question only needs one answer: a list of great resources for getting started with Oracle, including Database Administration, PL/SQL and SQL. You may find your question has been closed as a ...
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For a MySQL query, how do you determine physical and logical I/O?

I'm used to having a showplan in Microsoft SQL and have gotten lazy with using tools to tune MySQL queries. How can I determine physical/logical I/O for a query in MySQL? (EXPLAIN shows the index ...
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SQL Calculated Field in both SELECT and GROUP BY clause

Often in querying my MS SQL Server databases, I need to create a calculated field, such as this (CASE WHEN A.type = 'Workover' THEN 'Workover' ELSE (CASE WHEN substring(C.category, 2, 1) = 'D' ...
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Why are NULLs sorted first?

Why is it that when we have a NULL value in a column and we order by the value ascending, the NULLs are sorted first? select 1 as test union all select 2 union all select NULL union all select 3 ...
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IN and NOT IN for XML column

I have a table with a xml column. Xml is similar to <Root> <Row> <user>abc</user> <Rowid>1</Rowid> </Row> <Row> ...
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Why do we have SHRINKDATABASE command in SQL Server

I have read across the internet where Finest Developer says shrinkdatabse should be avoided as it causes increase in fragmentation and decrease in performance . So i would like to know from you guys ...