DO NOT USE this for questions targeting Microsoft SQL Server, use the tag sql-server instead. "SQL" is an acronym for "Structured Query Language", it is used in relational database management systems (RDBMS) to query, update, delete, and insert data as well as modify the structure of the database. ...

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3answers
883 views

Fixing a query that returns failed job information

I' using a SQL Server 2008 Sp3 environment. I have a query that returns information about failed jobs from the last 10 minutes. If a job has two schedulers (for example - a job that runs every 10 ...
2
votes
2answers
3k views

MySQL Replication without stopping master

I am currently setting up a replication for my database one of the ways i am thinking of synchronizing the master and slave without write locking the master, is by first taking a log position then ...
5
votes
1answer
1k views

How to improve performance on PostgreSQL when using multiple concurrent processes?

Seeing query performance which is not satisfactory on our Python application, which runs several processes that use SQLAlchemy core to access a PostgreSQL 9.2 database. We may have around 100 - 200 ...
1
vote
1answer
703 views

Question about Oracle's interpretation of “host cpu utilization” in v$sysmetric view

I am studying the v$sysmetric view from Oracle and trying to understand what is Oracle's interpretation of "Host CPU Utilization" It says in the metric_unit as % busy/(idle + busy), but what is busy? ...
1
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0answers
617 views

Efficiently retrieve big amount of data based on date range

Table EVENTS TimeStamp |O.Name |Location |Source | 2008-11-12 |Pretorian|Európe |England | 2009-12-24 |Lex Rosa |Európe |Italy | 2010-01-01 |Nasdaq |USA |Whasington | ...
2
votes
2answers
2k views

Only one NULL for one part of primary key

I have two date columns : "start date" and "finish date". I want to make sure that there can be only one null value in the "finish date" column (which should be current state if it's NULL) for one ...
0
votes
1answer
114 views

Implementation of stack in MySQL

I had an abstract idea of implementing a stack in MySQL. Tried a lot of Google work but couldn't reach to any logical conclusion. The Stack must be a collection of tables with the stack top pointing ...
3
votes
1answer
22k views

What queries is Oracle executing, how frequently, and time-taken?

I have a (Java) web-application, that of course executes many queries (selects, inserts, updates, deletes) to the Oracle Database. I want to find out the following for last 7 days: SQLQuery ...
1
vote
2answers
61 views

Need logic to collate data

I have a table in the below structure. phone bigint answer_time datetime I should group all phone numbers, and its total number of attempts and mention its no:of time answered and no:of time not ...
0
votes
0answers
402 views

Error in creating trigger in phpMyAdmin

I have 4 tables: event: event_id(p.k) | uid | circle_id(f.k) activity: uid | performed_activity_id(f.k->event_id) | activity_type_id follow: follower_id | circle_id(f.k) notification: sender_id ...
1
vote
1answer
68 views

Hard Parse on Non-Identical Statements?

Let's say I have this query : SELECT X FROM Y If I run it for the first time then it would do a hard parse. After that, I run this query : select x from y With just a difference in alphabetical ...
2
votes
1answer
5k views

The Cluster service failed to bring clustered service or application 'SQL Server (MSSQLSERVER)' completely online or offline

SQL Server service restarted/stopped, which cause the production database down n find this errors in System log. ERROR5:The Cluster service failed to bring clustered service or application 'SQL ...
1
vote
1answer
519 views

mysql query - how to delete duplicates based on highest int?

I'm running a reverse auction website and I need to delete the duplicate bids and keep only the highest amount . lastPriceBid_rounded is the "amount". The duplicate is defined by the userId. ...
7
votes
2answers
1k views

Different results rebuilding an index online and offline

I have a non-clustered, non-unique index on a foreign key column of type bigint. When I rebuild the index online, the average fragmentation drops to 3%, with 2 fragments, and 30 pages. When I run ...
8
votes
4answers
673 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 ...
4
votes
1answer
85 views

Index Evaluation

I have been doing some index evalaution on a table and this is the first time I have ever looked at how well indexes are performing so and would like some advice on a certain index. The non ...
2
votes
1answer
3k views

Select the top 5 records and the specific column from each table in the same database

I have 50+ tables in a database. I don't want to use the following SQL on each table in a database. select top 10 * from {table_name} So, is it possible to display the first 10 records PLUS only ...
0
votes
3answers
6k views

How to select the first 10 records for each table in the same database using sql

I have 50+ tables in a database. I don't want to use the following SQL on each table in a database. select * from {table_name} So, is it possible to display the first 10 records for each table ...
2
votes
2answers
1k views

What is the difference between using varchar(100) and varchar(255)?

I want to know difference between varchar(100) and varchar(255) in terms of memory usage and programming problems of using more memory.
1
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2answers
204 views

Suggestion for storing a lot of simple data

I'm looking to crawl a lot of webpages (500,000,000,000) records and be able to store the linking structure for a later date. The way I planned on laying out the database was as follows: 2 Tables ...
3
votes
1answer
68 views

Special ordering

I have a hierarchical query but I don't manage to order it as I want. I have a column named sequence that indicates how to order it but the data is kinda mixed up and I cant do it properly. This a ...
7
votes
2answers
1k views

Is there any difference between putting a column alias at the start or the end of the column definition?

I've always seen and written my column aliases as SELECT 1 as ColumnName but today came across a query that used SELECT ColumnName = 1 Is there any difference in how these two queries get ...
0
votes
1answer
348 views

Connecting to an SQL Azure Database from SSMS - IP Restriction

I am trying to connect to a new SQL Azure Database via SQL Server Management Studio. The client box running SSMS is hosted on a production DB so we restrict access on 1433 to just a handful of IPs ...
5
votes
3answers
138 views

Filtering data that could have more than one category

I have a table like the following: Annotation ( document, term, category ) Where document and term are some ID, while category is an integer. The couple document - term is not unique, ...
2
votes
2answers
1k views

Problem with order by in MySQL subquery

I'm running a query that runs in about 2 seconds when the subquery does not include the order by date_sold clause. However, when I add the order by clause, the query runs forever. I'm confused, since ...
0
votes
2answers
93 views

How to organize a single query to several sql servers?

I need to make an inner join sql query to several SQL Servers (one is 2000 and another is 2008 R2). The query is like the following: SELECT k.ID, k.NAME, k.BIRTH, l.PROFILEID FROM ...
0
votes
1answer
73 views

Faster joining on 'most recent' related rows

I have a bug tracking application. The bug table stores very little, because every state change to a bug happens by adding a comment. For example, the current state of a bug is determined by the state ...
9
votes
2answers
2k 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 ...
1
vote
1answer
990 views

How and what is the most efficient way to join two tables, retaining a particular field from both?

I have two tables, with the following columns: Table 1 ID Component Data1 Data2 Table 2 ID Component Data3 Data4 If I have rows in these tables, with items Component1, Component2, Component3, ...
3
votes
1answer
76 views

Locating row in index page

In clustered index, we have root, intermediate and leaf level pages. Every page has few records where indicating range of pages from level below. How SQL check whether some index key belong to ...
2
votes
2answers
135 views

Query to find Maximum friends not giving correct resuts [closed]

Table Schema for the Likes table: id id1 1 2 1 3 2 1 I count the total number of Likes for each student with this: select id,count(*) from friends group by id I have to find the students with ...
1
vote
1answer
193 views

Mysql setting a record as deleted or archive

Is there any way to omit some records in mysql select statement and not deleting them? We can easily add a column for example deleted and set it to 1 for deleted ones and keep them but the problem is ...
0
votes
0answers
414 views

Understanding the time difference between data grid initial display and export/full display using Toad for Oracle

I am trying to run a query on a local Oracle DB and output the results to a .CSV file. The query runs in a decent amount of time (usually less than 5 minutes), but returns tens of thousands (possibly ...
1
vote
2answers
2k views

Strange behaviour of a query with order by and rownum on Oracle's Exadata server

I am executing the following query on two different database servers: SELECT start_date, end_date, resort_id FROM employee_activity WHERE employee_id = 27 AND start_date < ...
4
votes
1answer
698 views

Query records that chain together based on date gaps

I have a table in SQL Server 2012 with the below simplified schema and I need to define a query that grabs the most recent record and then returns the chain of records that have less than 30 days of a ...
2
votes
2answers
4k views

SQL Server - backup / restore schema only (not a duplicate if that's what you're thinking!)

We have a DB on over 100 servers of which we want to backup / restore the structure of just 1 at a time to a specific UAT database. They're all called the same thing but vary in terms of schema - ...
3
votes
2answers
17k views

Selecting data from multiple rows into a single row

I have a table that has columns like following. Batch number is a database design thing like row number demand_id batch_number debit status customer 34 1 ...
0
votes
2answers
2k views

Does MYSQL join before LIMIT?

Imagine that I want to populate the last 10 questions of stackoverflow. I have a table that keep the questions list, a table to keep the question info, a table to list question's asker. Now imagine ...
4
votes
2answers
762 views

How to sort category by path and sort order?

first of all I am sory for my english. My category structure is shown below. My purpose is to get category structure with single query. I sort my table by path and I get category tree. sort_order : ...
0
votes
1answer
46 views

Need Some SQL help [closed]

I need to pass the following SQL statement: UPDATE table_products SET shipping = "a:5:{s:16:"min_items_in_box"; i:0;s:16:"max_items_in_box"; ...
2
votes
2answers
2k views

how does SQL Server 2008 handle joins internally?

for example, I have tables: User and Order User Table: UserId, Name, Address, Phone, Age Order Table: OrderId, UserId, Date, Item, Quantity SQL: select User.Name, Order.Date From Order JOIN User ...
1
vote
1answer
63 views

Correct data model for users with clients

I have an application where users are granted access. Part of the system allows users to have their own 'clients'. I have a users table ******************************** users ...
1
vote
1answer
188 views

Multiple primary keys

I am new to database design and have been looking at some example data models here. One thing I don't understand is if you have a table like client_addresses from the link above: ...
1
vote
3answers
123 views

Live monitoring SQL statements on SQL Server

How can I monitor running SQL Statements for my SQL Server, is it possible using only SQL Server without 3rd party tools? As an alternative can anybody recommend any free tool which can monitor ...
1
vote
1answer
822 views

Query is not using indexes on third table in left join

My query is not using indexes on third table(pci promotion_coupon_images) . i was tried with using index and force index in query but there is no change in result. any body please suggest me how ...
8
votes
3answers
2k views

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 ...
3
votes
2answers
9k views

ORDER BY clause is allowed over column that is not in SELECT list?

In theory, every statement in SQL Server create virtual table passed to next statement. In other words, when FROM and Where clause are finished, next step is SELECt columns from virtual group created ...
0
votes
1answer
319 views

Create a VIEW that spans 3 tables

Sorry if the title is not clear - feel free to improve. Here are 3 tables (not all data is relevant to the question): CREATE TABLE `content` ( `id` int(10) unsigned NOT NULL AUTO_INCREMENT, ...
1
vote
1answer
47 views

simple query is not using indexes

My query is not using indexes. it was taking around 5 seconds. output is 500 rows only. it is a simple query Please find the explain plan and table structure here. Explain Plan mysql> explain ...
4
votes
2answers
808 views

Restore SQL Server database from .sql files

So we had an encrypted database that puked and killed our whole SQL Server setup. Sucks about our data, but we were smart enough to have our data structures / stored procedures / functions in Git The ...