Structured Query Language (SQL). For questions about the language, not Microsoft SQL Server (tag sql-server).

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Is it impossible to store 2^266 records on a database of some kind? [closed]

Each records weighs 52 bytes, is it possible in today's technology if someone had the storage needed? What kind of db would hold the data and will make it possible to retrieve it. An example record: ...
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0answers
61 views

Reduce read write delays in specific database setup

I have a database with a large table with 15 columns (type double). It contains a large amount of data (~ 100 rows of data for every second. Holds 3 days of data). I also have a real-time program that ...
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1answer
2k views

Delete Query takes a long time

I have a innodb table that counts circa 1 billion entries. I started a delete operation (with a small where condition on an indexed column) that should delete a lot entries, leaving circa 100 million. ...
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3answers
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How to Log All mysql queries into log file?

I am using Mysql 5.6.12 under Wamp server environment. Now I want to log All queries into ".log" file, the queries which are running by PHP or from PHPMyAdmin, I want to log them...
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1answer
407 views

Difference between COUNT(ColName) vs COUNT(ALL(ColName))

Both query return the same output: select COUNT(id) from Employee select COUNT(All(id)) from Employee So what is the difference in SQL-Server 2008R2?
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1answer
567 views

UPDATE CONCAT without duplicates

I would like to concatenate multiple values ​​and remove duplicates (case-insensitive) in the same field with SQL only. Without using a unique key or stored procedure. Ex. ...
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1answer
5k views

How to insert default values to a table with not null columns?

I have several tables with different number of columns, each can be either real or int, both not null (I can define them all real if required). I would like to write a query that inserts a row with ...
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6answers
5k views

Efficiently storing irregular/repeating intervals (think calendar/events)

I am developing a service that relies on users being able to recieve messages that they themselves choose. These messages need to be stored somewhere before they are send for processing. Right now ...
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1answer
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Is there any way to get the estimate cost of executing a query in MySQL?

In PostgreSQL, EXPLAIN or EXPLAIN ANALYZE will show the estimate cost of executing a query. But EXPLAIN in MySQL doesn't provide this information. How can I get the estimate cost without installation ...
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1answer
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Postgresql Database on external HD

I'm completely inexperienced with PostgreSQL, but have to do some work on it, and I have been googling for a solution for almost two days. I hope someone here can help me out. I have a PostgreSQL ...
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2answers
76 views

MySQL query optimization for legacy application

I'm working with a legacy application that started out with little data years ago (developed by a third party custom for this client), and now we're seeing MySQL load skyrocket on this query alone. ...
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1answer
871 views

Moving a heap between filegroups

I would like to move the tables in my database from one filegroup (Primary) to a another (a new one). I can find lots of advice on this concerning tables with clustered indexes but all these tables in ...
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0answers
812 views

Alphanumeric field in MySQL

I need to create a character field with some rules, they are, Field name: contract_number. Rules: Contract Number Contract number must be alphanumeric. Contract number must be unique. Contract ...
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2answers
2k views

SQL Server hardware configuration: Best Practices [closed]

I inherited a relatively new database server that is light on hard drives. Currently, everything - OS, SQL Server, hosted databases, etc. - is running on a single partition in a two-drive RAID 1 ...
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1answer
4k views

How to connect client applications to SQL SERVER 2012 cluster?

Following are the environment Details : Database Server : SQL SERVER 2012 Operating System : Windows Server 2012 Single instance of SQL SERVER 2012 is installed in cluster configuration with 2 ...
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1answer
339 views

Resolving Cyclical Reference in Referential Relationships

I'm designing a small SQL Server Compact Edition database and am attempting to enforce referential integrity. The database is a simple backend for a small desktop application that functions as an ...
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1answer
2k views

Do SQL Server Views update their data types automatically based on what tables feed them?

Someone mistakenly created a bunch of nchar fields in database tables. I noticed this, and after examining the issue, we're moving these fields to nvarchar types and trimming the values inside. In my ...
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1answer
380 views

Add 0 into array_agg if there is no matching data

I wrote this view, and it is selecting almost everything I want, but I do not get results for all: project_keywords(which has_many project_report(keyword_id, project_id)) So a project_keyword has a ...
2
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1answer
494 views

Can't find stored procedure for updating after creating it

I'm trying to create a procedure to update my table create proc UPDATE_PRODUCT @ID_CAT INT, @ID_PRODUCT VARCHAR(30), @LABEL NVARCHAR(30), @QTE INT, @PRICE VARCHAR(50), @IMG IMAGE AS UPDATE ...
2
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1answer
57 views

Find the SQL query that caused an event in the past

I have a database in which I noticed that one of my tables is missing. I haven't used this database for over three months and now I want to find out who caused this, when this happened, how it ...
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1answer
2k views

Data History Table vs Using a Current Record Flag [closed]

There are two strategies when dealing with data records which contain multiple versions. One is to have current records in one table, and their past versions in a history table. The other is to have ...
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1answer
810 views

How to aggregate pairs of id values into groups

I have a table with two id columns id1 and id2. Each row shows that 2 id values have been linked together. My actual data has both id columns as varchar(20) but I have used integers in the example ...
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1answer
482 views

Make MySQL dump from parts of each table

I need to export some data from different tables. I tried this query select * into outfile 'C:\Users\\User\\Desktop\\ololo.sql' from db.users where id % 2 = 1; After this query, the SQL file was ...
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2answers
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How to retrieve the Capture Instance for a given table?

Working with SQL Server 2012, I have a hierarchical table layout (TPT). All tables "inherit" from the same base table (dbo.DataObjects). All tables have history tracking via CDC enabled. I am trying ...
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1answer
79 views

Postgresql view how to do the query

I have 4 tables: Project: id name Keyword: id, name ProjectKeyword: project_id, keyword_id (project has many keywords, keywords has many projects) ProjectReport: project_id, keyword_id, ...
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1answer
297 views

Is not in (a,b,c) faster than where != a, b, c

When writing a query which is faster? SELECT * FROM table where column not in (a,b,c); or: SELECT * FROM table where column != a AND column != b AND column != c ;
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5answers
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Steps after restoring to a different server

We have a 30 GB Database on SQL Server 2008 R2 Standard Edition. Yesterday we backed up the database and restored it to a different Virtual Machine which has exactly the same specs as the previous ...
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3answers
666 views

Can we restrict the number of connections to a database in SQL Server?

I have a database on SQL Server. My web application contacts this database. Is there a way in which I can restrict the number of connections to this database through some settings on the SQL Server?
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0answers
107 views

Database migrated to SQL Server 2005 with 80 compatibiltiy from SQL Server 2000 experiencing locks

I am supporting an application whose code my company did not write, and was originally developed back in 2000-2002, by a company that no longer exists. The code, while not great to maintain, ...
5
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2answers
10k views

Find which session is holding which temporary table

We have a SQL Server 2005 database the temp database has become full. By going into SQL Server Management Studio I can see all the temporary tables in the tempdb. Is it possible to tell which session ...
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1answer
230 views

Nightly reload of tables from a linked server

I have a number of tables that need to be reloaded nightly from a linked server. My current method of doing this is to create a nightly job to pull the data using something like the following: ...
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1answer
68 views

How to store chains of information?

I am currently trying to design a table structure that can capture report data (from various sources) in an ordered fashion. Let me give you an example: Each day I receive three separate reports ...
3
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1answer
4k views

Postgresql subquery speed much slower than individual queries

In Postgres 9.1. I am attempting to do a single query to get the timezone of a given postal code. I have data loaded in my database, and I am using PostGIS to store the coordinates of each postal ...
3
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2answers
158 views

Enhance performance of update query

I have a query that is running against a table with 50 million rows. The phone number is stored as a CHAR(10) and an ETL process is changing the phone number if it has certain values. We are seeing ...
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1answer
5k views

How to query-and-increase a value (counter) in a thread-safe way? (avoid race conditions)

In a table where each row has a counter (just an integer value), I need to get the current value and increase it at the same time. Effectively, I want to do this: SELECT counter FROM table WHERE ...
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1answer
240 views

Take database backup of a SQL server 2012 from local SQL Server 2008 R2

I have a SQL Server 2012 installation that has some issues with SQL Server Agent because of which I cannot schedule a job or a maintenance plan to take backup. What I am trying to do is to create a ...
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2answers
2k views

Assign maximum memory limit for a particular database in sql server

In my SQL-Server instance, there are many databases. I want to restrict the memory size of each database (for example 8 GB). When I tried using Resource Governor, there are options like ...
5
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2answers
4k views

Query across multiple schemas, unknown until execution time

I have multiple schemas that I need to query across. The schemas are not known in advance, for example: U111 U222 U333 I need to select across these three schemas from a specific table in each of ...
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0answers
56 views

1 SQL Instance on 1 box with multiple databases or multiple SQL instances on 1 box [closed]

I am a new DBA working for a charity and I have project to consolidate the multiple databases scattered across the organisation. I have identified the main databases that are mission critical to the ...
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2answers
267 views

How to drop table with all reference to this table

I want to drop a table, and this table has be many table's foreign key. So I want to drop all those reference (just refernece, not other table) within the drop table process. Is there any simple ...
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1answer
360 views

Aliases with correlated subqueries

I am looking at an example of correlated subquery with aliases from a PostgreSQL book: bpsimple=# SELECT * FROM orderinfo o, bpsimple=# (SELECT * FROM customer c WHERE town = 'Bingham') c bpsimple=# ...
2
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1answer
953 views

Azure Database Size Same Before and After Deleting Most of the Rows

I have a database hosted on Azure which is showing as nearly full, it is at 1017MB/1024MB. The table contained around 27000 rows, I have deleted 20000 of those rows to try and free up space, however ...
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0answers
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Conceptual data model for a billing system

I am working on existing MySQL database, my task is to create a new data model for a billing system on that existing application, I have created a conceptual data model, as given below, My ...
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1answer
10k views

How To Execute an Integration Services (SSIS) Package from a SQL Server Stored Procedure

i am executing query like this on sql server 2008 R2 DECLARE @returncode int EXEC @returncode = xp_cmdshell 'dtexec /f "C:\certs\SSIS Disposition\SSIS Disposition\SSIS Disposition\Package1.dtsx"' ...
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2answers
199 views

How to merge column in mysql depending on match

I have one table which looks like this in mysql column1 column2 name column3 data 1 1 foo 1 1.5 1 1 foo 2 2.5 1 1 foo 3 ...
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0answers
70 views

Tagged questions

I have similar to StackExchange network that utilises tagged questions. In my web application Users also can find questions by tags. The query below returns a set of tagged questions: SELECT ...
5
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3answers
2k views

Storing a Shipping Address Best Practice

I'm building a checkout system which needs to store the customer's shipping address in the database and am unsure the best way to go about it. Currently I have an addresses table which stores each ...
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1answer
196 views

creating table result in errno 150

I'm trying to create the following schema, but I'm getting errors when I'm trying to create project and staffphone tables. Not sure what is it complaining about. mysql> CREATE TABLE staff( ...
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0answers
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What does this icon in SQL Server mean? [duplicate]

Can someone tell me what the icon of a server and a blue database symbol means. It is attached to database engine instance in my object explore view. (I apologize, I am unable to add a image of the ...
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1answer
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Putting a condition related to a table in JOIN is better?

I have seen this a lot that people are putting table related condition on JOIN clause. See this example, SELECT i.Name FROM sys.TABLES AS tbl INNER JOIN sys.indexes AS i ON (i.index_id > 0 ...