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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Querying a database efficiently for a huge chunk of data

Here is my query SELECT * FROM ( SELECT a.*, rownum rnum FROM ( SELECT id, data FROM t ORDER BY id ) a ...
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2answers
971 views

CREATE INDEX for long columns

I am looking for alternative to create index on long column: create table line ( field_key integer not null, value varchar(4000), ... ); create index key_value_idx on line ...
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1answer
280 views

Is staggering reindexing jobs a good strategy?

I have inherited a server with 35 databases and a job that reindexes all tables on all databases (using sp_MSForEachTable). It's taking over 14 hours to complete and is now blocking other processes. ...
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1answer
307 views

SQL Server 08: Union over while

I've done some reading on this, and I keep seeing people say it's a bad idea, but hear me out! I have a stored procedure which needs to find a series of timeslots over a number of days. Due to the ...
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2answers
357 views

Check Index Fragementation Query

I'm completely stumped. I'm a relatively new SQL Server DBA so I'm at a loss with the following situation; hoping maybe someone had an idea. I have a new production SQL Server (Windows Server ...
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2answers
158 views

Optimize simple query using ORDER BY date and text

I have a query to a table in Postgres with an order based on a date field and a number field, this table has 1000000 records The data types of the table are: fcv_id = serial fcv_fecha_comprobante = ...
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1answer
573 views

Cascading Inserts in MySql

I have a users table that has a one to one relationship to a user_preferences table (primary foreign key user_id). When a new row is added to the users table (new id added), is there a way to setup ...
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1answer
197 views

SQL from/where or join?

I was wondering performance wise what would be faster a join or a from and where query. I am trying merge and update query but performance is terrible?
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3answers
754 views

sql server 2008 - controlling size of log file

I am getting this error. Msg 9002, Level 17, State 4, Line 2 The transaction log for database 'SalesDWH' is full. To find out why space in the log cannot be reused, see the log_reuse_wait_desc ...
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3answers
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Can a RDBMS connect to a remote server, execute a select query and copy them into a local table just with SQL commands?

I'm sorry it may sound stupid but I've been wondering about how multiple databases are automated before the virtualization era. Can a DB Adminsitrator make a stored procedure to get data from a remote ...
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1answer
2k views

Minimum user rights for connecting MS Sql database remotedly

I have followed this tutorial for getting connected to a Microsoft SQL Server. I connect with ping functionality of Glassfish Server and thus I have to give some user rights to be able to even ping ...
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2answers
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Is it a bad practice to always create a transaction?

Is it a bad practice to always create a transaction? For example, it is a good practice to create a transaction for nothing but one simple SELECT? What is the cost of creating a transaction when it ...
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1answer
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Stored Procedure to return dynamically created table data

Quick back story, we are working with an outside vendor that has a survey system. The system is not necessarily designed the best in that when you create a new survey and the system creates a new ...
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1answer
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Order by column should have index or not?

I have added indexes to table which are used for searching result. I am showing results by ASC or DESC order. So that column should have index or not? I have 2 more indexes on that table. How ...
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2answers
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Updating 700 million rows to same value

I've got a data warehouse (oracle) where I need to set a column to the same value for all 700 million rows. I don't have admin access, or access to an admin, so this needs to be accomplished with ...
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5answers
940 views

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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2answers
279 views

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 ...
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2answers
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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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6answers
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How do you submit a List of items to a Stored Procedure to limit results? [duplicate]

Possible Duplicate: Passing array parameters to a stored procedure Lets say you want to filter results by a List of uniqueidentifiers such that your SQL statement would read: WHERE ...
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4answers
3k views

How do I do a complex GROUP BY in MySQL?

I have a table that contains several keys into other tables (where each key is comprised of multiple columns). I would like to be able to group rows together that have an equal key, but I don't want ...
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4answers
421 views

Is a join optimized to a where clause at runtime?

When I write a query like this... select * from table1 t1 join table2 t2 on t1.id = t2.id Does the SQL optimizer, not sure if that is the correct term, translate that to... select * from table1 ...
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1answer
214 views

Table order in Join Query

if i say: Table1 left join Table2 is it the same as saying Table2 right join Table1 ? In other words, should i expect to get the same results from 2 identical queries where the only thing that is ...
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4answers
3k views

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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2answers
796 views

Database locking issues?

I have run into a transaction related issue on a SQL Server 2008 production database. A brief overview is that we have a website that has numerous concurrent users around the state, who do GUI type ...
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4answers
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Multiple operations using WITH

Is there a way to execute multiple operations using the WITH statement? Something like WITH T AS ( SELECT * FROM Tbl ) BEGIN OPEN P_OUTCURSOR FOR SELECT * FROM T; SELECT COUNT(*) INTO ...
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2answers
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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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1answer
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Difference between count(*) and count(1) in mysql?

In MySql we can count the total number of records by using count(1) or count(*). Is there any technical difference between them?
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1answer
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Changing ANSI_NULLS setting on a table

Can we use the following query to update ANSI_NULLS option. sp_configure 'allow updates', 1 reconfigure with override update sysobjects set status = status | 0x20000000 where name = 'tblClient' ...
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2answers
446 views

SQL Server configuration / specification recommendations and advice!

I am about to deploy a new server at work as follows: Dell T610 2 x Xeon 2.53 Quad core 24 GB RAM 1 x Perc H700 RAID controller with 1GB Non Volatile memory 8 x 300GB 15k SAS Hard drives I am looking ...
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2answers
794 views

Using totals on aggregates to improve performance

I have two tables: details and totals of these details. Details (Slow solution): select OrderId = r.OrderId , TotalQty = SUM(r.Quantity) , ...
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1answer
424 views

Dealing with temp tables when I have not control over db variables

I have no control over things like tmp_table_size and max_heap_table_size, and so as our tables grow the time taken by queries requiring temp tables is growing geometrically. I am wondering if there ...
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2answers
114 views

Order of columns in a compound index in PostgreSQL (and query order)

I have a table with 50K rows. It is actually a PostGIS table. The query has 4 parts (1 mandatory) (3 Optional) intersection box (a geography rectangle) with 4 lat,long (I use st_intersects) ...
4
votes
1answer
365 views

SQL Server 2008 R2 Upgrade (Express to Standard) fails. No “Select Instance”

Hello there, i got stuck in the progress of upgrading 3 systems from SQL Server 2008 R2 Express Edition --> SQL Server 2008 R2 Standard Edition Problem: The Option "Select Instance" in the ...
4
votes
1answer
794 views

Syntax of INNER JOIN nested inside OUTER JOIN vs. query results

TLDR; If you look at the 2 execution plans, is there an easy answer to which is better? I purposefully did NOT create indexes so it's easier to see what's happening. Following up on my previous ...
4
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1answer
511 views

How do I get the aggregate of a window function in Postgres?

I have a table containing a two columns of permutations/combinations of integer arrays, and a third column containing a value, like so: CREATE TABLE foo ( perm integer[] NOT NULL, combo integer[] ...
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votes
2answers
305 views

Select longest continuous sequence

I am trying to construct a query in PostgreSQL 9.0 that gets the longest sequence of continuous rows for a specifc field. Consider the following table: lap_id (Serial), lap_no (int), car_type ...
4
votes
2answers
159 views

Checking a wide table for nulls [duplicate]

Possible Duplicate: Test if any fields are NULL I am new here. I have a table with 70-odd columns. Is there a way I can check the number of rows with at least one null value in any column ...
4
votes
1answer
4k views

oracle format specifiers: to_number vs to_char

SQL> select TO_NUMBER(123.56,'999.9') from dual; select TO_NUMBER(123.56,'999.9') from dual * ERROR at line 1: ORA-01722: invalid number SQL> select TO_CHAR(123.56,'999.9') ...
3
votes
1answer
282 views

How to separate out individual sql statements from Oracle SQL script for execution from java code

I have Oracle DB 11g Enterprise Edition and I want to execute sql script from my java code. I am reading this sql script from a .sql file and the script contains statements such as create table, ...
3
votes
1answer
388 views

How does Log shipping knows to keep track

I have set up log shipping between 2 SQL Servers (SQL Server 2008 and SQL Server 2012). At first i took a full backup of the first one and restored it on the other one and than i set up the log ...
3
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2answers
371 views

Full Text Search With PostgreSQL

i have a table with this rows: Stickers ------------------------------------------------------ ID | Title |Keywords (ts_vector) ------------------------------------------------------ ...
3
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1answer
268 views

How to categorize rows by SUM of a column in mysql?

I have a table as id num_items folder 1 4 2 33 3 74 4 41 5 24 6 34 7 46 8 55 9 11 I want to assign folder number to rows but limiting the number of items in each folder (e.g. ...
3
votes
1answer
2k views

Import CSV File

Currently, we have a DTS package on SQL Server 2000 that imports a file called suicoweb.csv. The DTS csv file properties pages look like this. Here is a sample line from the CSV file ...
3
votes
2answers
5k views

Using Same CASE WHEN Conditions For Multiple Query Columns

Is there a "better" way to rewrite a SELECT clause where multiple columns use the same CASE WHEN conditions so that the conditions are only checked once? See the example below. SELECT CASE ...
3
votes
3answers
416 views

SQL JOIN Syntax in MS SQL

I have been taught in my MSSQL classes, this is how to join two tables select * from FirstTable A JOIN SecondTable B on A.ID= B.ID Now in my professional life, I came across JOIN queries like ...
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5answers
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Copying Oracle 11g express Database from one server to another

Basically, I am a MS-SQL developer,and relatively new to Oracle. Even after great deal of research, I was unable to find any way of copying entire database from one server instance to another. In ...
3
votes
2answers
2k views

SQL Server 2008 T-SQL select hanging, but not dead locked

This is a pretty strange issue so bear with me. I have a stored proc that does some heavy duty processing. When it runs well it usually takes a few minutes depending on server load, but occasionally ...
3
votes
2answers
418 views

Transaction Log 16GB on 2MB database [duplicate]

Possible Duplicate: Why is My SQL Server Transaction Log Growing or Running out of Space? The transaction log in one of my client's databases is 16GB, when the database itself is only 2MB. ...
3
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2answers
731 views

Can the sorting from an ORDER BY statement be saved explicitly with only one UPDATE statement?

I have this table: SELECT * FROM items id | item | position ---|-----------|---------- 1 | USB cable | 0 2 | SD card | 4 3 | Mouse | 2 4 | Keyboard | 0 5 ...
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2answers
457 views

Testing Query Speed

When I'm running a query for the first time, it takes x miliseconds to be executed. When I run it the second time it takes a lot less time. I assume that it is some caching involved in this mechanism, ...