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

learn more… | top users | synonyms (2)

1
vote
1answer
151 views

How can I design this database?

So I have a ton of transaction logs in pipe-separated format spread across a few dozen files. Concatenated into one file, it's around 2.4 million lines. Each transaction has a store number and a ...
0
votes
1answer
305 views

MySQL Loop Through Each Row

I have two tables, division & template, in a MySQL database. division - DivisionID - DivisionName template - TemplateID - TemplateName Here is an example of my current data ...
2
votes
2answers
444 views

SQL Backup tuning large databases

I am tuning SQL backups using compression, writing to multiple files, and changing the BufferCount and MaxTransferSize options. I have SQL instance with a 4 TB database and several smaller databases ...
1
vote
1answer
537 views

Select statement for selecting every week's log record

Here is a simplified version of the table in question: +------------------------------------------------------+ | DatabaseName | LogRecordNumber | LogTimestamp | ...
1
vote
2answers
350 views

Are there any special characters that are never allowed in SQL?

I am a Java programmer. We always make database-related things configurable so that they can be easily modified by the DB team as per their requirements. I want to make some queries as configurable, ...
0
votes
0answers
63 views

Paging via Number of Result Record vs COUNT(*)

I have been working on fixing a piece of code for a customer that has been very slow for them. I have made that fix, and thats all lovely, but I noticed something odd in the paging. When the query ...
5
votes
2answers
491 views

How to store immutable, unique, ordered, lists?

I have an entity with millions of instances. Each instance has to reference an ordered list of items. The lists have to be unique so no list will be stored more than once. But once created, both lists ...
1
vote
1answer
4k views

Store the resulting list of a SELECT in a variable to count AND use the result

I have stored procedure that uses a cursor and for every fetch a duplicate SELECT, once to determine the number of IDs found (SELECT COUNT(ID) FROM TableA WHERE something.. @cur_var) and if the ...
2
votes
1answer
32k views

Case with multiple conditions

I need to change returned value, from select statement, based on several conditions. I tried something like that: ,CASE i.DocValue WHEN 'F2' AND c.CondCode IN ('ZPR0','ZT10','Z305') THEN c.CondVal ...
1
vote
1answer
278 views

SQLAnywhere: Visualize in real time CPU and RAM consumption of sql connections

I want to keep track of which connection use most of resources. Within Sybase Central (SQL Anywhere 9, 12), for each server and database, we have pane to check in real time All Connected Users and ...
2
votes
4answers
111 views

Trigger or Stored Procedure?

Let's say I have two tables, foo and bar: CREATE TABLE foo( foo_id serial NOT NULL, count integer NULL, PRIMARY KEY(foo_id) ); CREATE TABLE bar( bar_id serial NOT ...
3
votes
1answer
387 views

SQL Azure Performance of new servers

I have a fairly small database ~200MB which when running in the web edition of SQL azure is lightning fast. I've switched it to the basic edition and all of a sudden a group of queries which took less ...
3
votes
1answer
135 views

Why postgres is using an odd index with no relation to the query

(Debian 7, Postgres 9.3, dedicated machine with huge cache) I have one big table called process_data (14gb) and another tiny lookup table called process_location. I'm doing a query between these two ...
0
votes
1answer
64 views

Design: Fitting variable hierarchy of text files into a relational db

I have a large data corpus (several TB) made up of data gathered through customer support queries. I've been asked to set up a database to make this data more accessible, but as I'm kind of new to ...
1
vote
2answers
203 views

How to deal with very large transaction logs in SQL Server [duplicate]

Here is my situation: I have being asked to deal with a SQL Server 2008 R2 database that has a transaction log that is several times bigger than the database itself. The database is in full recovery ...
1
vote
1answer
81 views

Getting Time Duration

I have a table like below: I want to get time duration for each record which SPEED is greater than 100. I written a function for that, it’s working fine , but my problem was i have millions of ...
1
vote
1answer
86 views

Adding a “position” number in Mysql

I got the following query and result currently: mysql> SELECT songname,COUNT(*) as count FROM etrstats WHERE songname != '' AND `when` >= DATE_SUB(CURRENT_DATE, INTERVAL 1 MONTH) GROUP BY ...
4
votes
2answers
10k views

What are some common and useful fields for a users table in a database?

I want to begin implementing user functionality on my website, but I'm not sure exactly what kind of information I should be storing. Obviously the basic things like username, password, password hash, ...
-1
votes
3answers
610 views

How to load multiple values in cell from Excel to SQL Server many to many table [closed]

I have values in excel like this. StudentNumber| Subjects 1| english, science, maths 2| maths, biology 3| history, zoology I have Student table in database ...
1
vote
1answer
5k views

SQL Server 2012 how to create new schema from existing database selecting only subset of database objects?

I'm looking for a way to create new schema from existing database selecting only subset of database objects. I.e. I want to have some "database representation" which only includes subset of tables ...
0
votes
1answer
770 views

Insert record only if a combination of column values doesn't exist

I have a simple MYSQL insert query: INSERT INTO table('col1','col2','col3') VALUES('123','456','some text') I want to insert only if the above combination of columns does not already exist and this ...
1
vote
2answers
54 views

Multidimensional aggregates

Suppose one wanted to cache simple aggregate data over a table or grouped parts of a table, one could simply make a table with the aggregated results. If the original table is only appended to, it is ...
0
votes
1answer
40 views

multi-column FKs with NULL values

I understand that in PostgreSQL if there is a multi-column FK from table B to table A and one or more of the FK columns in table B are nullable then the FK is still considered as "honored" for the ...
1
vote
1answer
74 views

Matching a value with every element of a set of values - Postgresql

I'm new in Postgres and I can't achieve what I'm trying to do. I have a list of films in a Films table ID_FILM FILM NAME 1 Terminator 2 Forrest Gump 3 Nueve reinas A ...
2
votes
2answers
294 views

Call UPSERT function multiple times to different inputs

I have a function: merge_vehicles(vid, cid, vname, reg_no, name, name_1st) Can i call it multiple times on inputs like (2335, 55, '246BDH', '246BDH', '811', 1), (2336, 55, '038THX', '038THX', ...
0
votes
1answer
38 views

Select Ingredients of a product based on unit type

I have three tables UnitType,NutritionMaster, NutritionInProduct UnitTypeID UnitName 1 100ml contains 2 250ml contains NutritionID Name Description 1 Energy NULL 2 ...
0
votes
1answer
315 views

moving binary database folder is causing issues with innodb tables

so I have a mix of myisam and innodb tables on a database. (its a pretty big db 30gb) I copied the folder of the database from one server to the next /var/lib/mysql/databasename well the myisam tables ...
-3
votes
1answer
159 views

Best design to handle multiple query keys [closed]

I am designing a postgresql database for an online card game. I want to provide users with the option to access their play history - users can see log of their games. The data I want to save has the ...
2
votes
2answers
9k views

Problem sending an attachment using dbo.sp_send_dbmail

This question has been asked on the main stackexchange site I was referred here by a user there. ...
0
votes
1answer
31 views

MySQL - Arrange a table so that it shrinks as much as possible?

I'm a newbie and I have +10 million articles(200 to 1000 words) in a InnoDB table. I use this to select them: SELECT article,title,other_fields from table where id=123; There is no full-text search ...
0
votes
1answer
38 views

MYSQL improve query performance when using OR

I have a very simple MYSQL table with 2 columns and I run this query: SELECT * FROM table WHERE (col1 = '123' AND col2 = '456') OR (col1 = '456' AND col2 = '123') Col1 and ...
1
vote
2answers
32 views

MySQL improve query syntax

I have this simple MySQL query: SELECT * FROM table1 INNER JOIN table2 ON table2.col = table1.id WHERE table1.id = '123' id is the primary key in table1. table2 has composite primary key of two ...
0
votes
1answer
2k views

Oracle Nested Query with Group By and Having Clauses

So here's the question Find the IDs of aircraft which have flown more distance for a destination than the average distance of all flights for that same destination Here is the schema ...
3
votes
2answers
309 views

Stored procedure takes 18 seconds on first load, 0 seconds on subsequent loads, waiting several minutes makes it slow again

I have a stored procedure that returns a lot of data for a business dashboard. On first load it takes 18 seconds, after that it takes 0 seconds, even if I change the input parameters at random it ...
-1
votes
2answers
53 views

about latest row in sql server

I have table like id name When I inserted new row after that, I want to know which is the latest record in my table .. How to write a query for this ? I don't want to use any primary key or ...
0
votes
0answers
54 views

Crazy SSRS Issue

We are working a data center migration and are to the SSRS boxes and I am having trouble. SSRS is installed on a server alone pointing to the ReportServer and ReportServerTempDB on a different SQL ...
1
vote
0answers
107 views

MySQL not using multicolumn index on self join

I'm trying to optimise a query that performs an inner join with itself. The table size is currently 10GB ~50 million rows. /* Count all occurrences between start and end site id of a given speed ...
0
votes
1answer
97 views

Steps or evaluation order of the SQL statement

How the SQL statement containing simple statement like Select x From y Where z Having, order by , group by etc. are evaluated.( In which order they are evaluated.?)
0
votes
1answer
107 views

Reducing size of datatype involved in index fails where as increasing size work

This question is related to my previous question Database events that will cause deletion of index For example if i create a table like CREATE TABLE dbo.Customers (ID INT IDENTITY(1,1) PRIMARY KEY ...
0
votes
1answer
51 views

For each record, count records dated earlier in PostgreSQL

I have a table that contains a column year. I need, for each row, calculate the number of entries where the year is less than that in the row. So that the output would look like: col1 | col2 | ...
0
votes
1answer
58 views

COUNT() and link between tables

I have some difficulties to make a query. Basically, I have a 3 tables: member, build and up: member --+--- id|... build --+-----------+--- id|member (fk)|... up --+-----------+--------- id|member ...
0
votes
1answer
79 views

In a banking organization, why would account balance be declared as varchar and not decimal?

I worked in two organizations where I found money related columns are defined as VARCHAR data type. I didn't get correct explanation from anyone. As the database team is totally isolated with our ...
0
votes
2answers
7k views

Find Underlying Data Type (int - integer) of Oracle Table instead of number

I can create an example table using following syntax. CREATE TABLE "TABLE2" ( "COLUMN_INT" INT NOT NULL, "COLUMN_INTEGER" INTEGER NOT NULL, "COLUMN_SMALLINT" SMALLINT NOT NULL, ...
0
votes
1answer
33 views

Only Filtered condition gets deleted from index after datatype change using SSMS

In SSMS if I create a filtered index we can see filtered condition in index properties. But if I change column type of a column involved in filtered index using SSMS , then after column type changes ...
0
votes
1answer
279 views

12 hour format time in SQL datatype

I can convert time datatype to 12 hour format using convert etc. But is there any option to save the time in 12 hour format in SQL tables using any settings or property or any other methods?
5
votes
3answers
597 views

Speed of MySQL query for the most recent 800 entries in chronological order

I have a MySQL database running on an Ubuntu box that pings 250 clients once a minute (24x7). My column names are: ip_address varchar(16), status varchar(7), timestamp datetime Been running it for ...
-1
votes
1answer
104 views

SQL Server 2008 Trigger

New to triggers. I have two tables. One for users & other for circulated mails. The circulated mails table has [Sender, Receiver...] users table has [Personal Number, Names, Email]. when we have ...
1
vote
1answer
312 views

Append duplicate records with count (mysql)

We need to update a set of titles that have some duplicate entries. Because of the size of the database I would prefer to use direct mysql method, but I am open to any solutions out there. If we have ...
1
vote
1answer
318 views

Composite Foreign key to single primary key [duplicate]

How do I create a composite foreign key to a table with a single primary key? For example suppose I have the following tables: CREATE TABLE Branches ( BranchId UniqueIdentifier DEFAULT ...
0
votes
1answer
56 views

Replication in mysql with many servers

There are 3 shops. In each of these is a mysql server. I want all servers to synchronize their date if at least one server changes the date. I read a bit of literature and realized that I need ...