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14
votes
7answers
18k views

Too many columns in MySQL

I have a table with 1699 columns and when I'm trying to insert more columns I get the too many columns in the table error. In this table I have only 1000 rows. For me the most important thing is the ...
6
votes
1answer
1k views

ANSI/ISO plans for LIMIT standardization?

Are there currently plans to standardize one best way of limiting the number of results returned by a query? The stack overflow question at Is there an ANSI SQL alternative to the MYSQL LIMIT ...
5
votes
3answers
14k views

How to check if I am hitting the Express Edition size limit?

I am confused. AFAIK SQL Server 2005 Express has a limit of 4GB database data size. However I have the following results from sp_spaceused: How can I check if my DB is hitting the size limit? Is ...
5
votes
2answers
386 views

What are sensible/rational character limits in a database e.g. for a persons name

This is a general question about database admin. Is there some kind of standardization for character limits on fields in a DB? It makes sense to specify character limits on the database end for ...
3
votes
2answers
94 views

How does TOPN influence a query with group by?

I have a query that looks like the following: Select t1.field1, t2.field2, sum(t1.field3) From t1 inner join t2 on t1.id = t2.id Group by t1.field1, t2.field2 It's simplified, normally there are a ...
2
votes
2answers
324 views

Why does adding LIMIT to my query make it crawl?

Simple query: select sum(score) total,name,gender,dob,country from users join scores on users.id = scores.user_id where date between '2012-01-01' and '2012-01-31 23:59:59' group by scores.user_id ...
2
votes
3answers
2k views

How to limit MongoDB database size

Are there any mechanisms to limit the size of a single database on MongoDB 2.6? I found some options like quota, quotaFiles and nssize but am unsure how to use them.
2
votes
2answers
281 views

Limiting the Number of Records Joined

How can I perform a query that contains a (one-to-many) join between two tables, which will only join up to a pre-defined number of joined records? So, lets say I have two tables, one for Matches, ...
2
votes
2answers
138 views

ORDER BY indexedColumn ridiculously slow when used with LIMIT on MySQL

The MyISAM table has 4.5m rows. Query with just LIMIT returns fast; query with just ORDER BY returns fast; combining both it never finishes. I've also tried USE INDEX(indexedColumn, Latitude, ...
2
votes
1answer
3k views

“Limit 1000,25” vs “limit 25 Offset 1000”

Recently I've found out that MySQL has a offset feature. I've been trying to find documentation about the results of offset, or the difference in between offset and the limit variant, but I can't seem ...
1
vote
2answers
179 views

COUNT(*) gives more than 1 with LIMIT 1?

I'm trying to count old records. Why does Postgres give a result of 1160, even though I set some limit, LIMIT 1 in this case? SELECT COUNT(*) FROM data WHERE datetime < '2015-09-23 00:00:00' LIMIT ...
1
vote
3answers
912 views

Get rows changed between two dates (latest and previous)

I have a table _sync_history with this data: +----+----------------+---------------------+ | id | object_name | sync_time | +----+----------------+---------------------+ | 1 | territory ...
1
vote
3answers
139 views

Longest matching suffix while using aggregate functions

Background Looking to find the longest matching string suffix. Setup Consider the following fiddle: CREATE TABLE noun ("label" varchar(10)) ; INSERT INTO noun ("label") VALUES ...
1
vote
1answer
387 views

Query with limit and order by runs too slow

I have the following table: CREATE TABLE dpg2 ( account_id integer NOT NULL, tank_id integer NOT NULL, battles integer, dmg integer, frags integer, wins integer, recent_battles ...
1
vote
1answer
247 views

Select with limit, get total count, optimize query [closed]

The site mimics the "likes" tooltip from Facebook, the only difference is that you can like or dislike the content. The tooltip shows the first 12 users that rated the content and displays the number ...
1
vote
2answers
130 views

Is there a more efficient way to set up this table

I'm looking to add a new feature in our production site that will show users 25 items they most recently viewed. I already record every view into various tables based on the item type, but querying ...
1
vote
2answers
574 views

MySQL/MariaDB Limitations

we're running MariaDB on our DB server. We have to install multiple databases on each DB instance (in fact each DB server runs multiple MariaDB instances) because each database must be separated. ...
1
vote
1answer
181 views

Can having a LIMIT on DELETE degrade performance dramatically?

I have a database project in php and mysql. For, hopefully redundant, data security I added a LIMIT 1 to the delete($uniqueID) php function we use. Nobody cared because records really aren't ...
1
vote
1answer
5k views

SQL Limit + count group?

I'm tracking all the visitors of my site using this table: Visitors table In my admin panel, I have an overview of which countries visited my site, where they came from, ..., but because over 20+ ...
1
vote
1answer
122 views

Requirement of SQL Server 2008

The software I am installing requires SQL Server 2008. I have SQL Server 2008 R2 Express Version. I am having problem in the setup and finally I am arriving on the conclusion that my SQL Express can ...
1
vote
1answer
28 views

MySql LIMIT + JOIN is stopping data from being returned?

I originally posted this question on stackoverflow, but then remembered there's a stackexchange specifically for databases! I've got two tables and am trying to return all profiles that are assigned ...
0
votes
2answers
111 views

PostgreSQL How to optimize a query with ORDER BY and LIMIT 1?

I have the following PostgreSQL schema: CREATE TABLE User ( ID INTEGER PRIMARY KEY ); CREATE TABLE BOX ( ID INTEGER PRIMARY KEY ); CREATE SEQUENCE seq_item; CREATE TABLE Item ( ID ...
0
votes
1answer
93 views

MySQL limits on huge number return zero rows

I have table about 1,000,000 rows. this query work well: SELECT * FROM `articles` WHERE `articles`.`hash` NOT IN ( '1z8y' ) LIMIT 2000,10 But this query return zero rows: SELECT * FROM `articles` ...
0
votes
2answers
1k views

limit and then group by in MySQL

I have a mysql table having following structure : payment_id(int auto_increment), emp_id(int), chargeTime(datetime), payment(double) I need to have three latest (with respect to chargeTime) ...
0
votes
0answers
16 views

MySQL failed connection attempts hitting max_connections

I run a couple of websites but I believe one of them is causing too many Connections Failed Attempts that causes max_connections variable to hit. Currently, max_connections=2500 (already large) but ...
0
votes
1answer
52 views

Does LIMIT 1 still have effect on a unique column

I know that adding LIMIT 1 when searching for only one record makes a lot of difference when it comes to performance. But does it still have any effect when we search a column with a unique ...
0
votes
0answers
30 views

LibreOffice Base randomly changes character limit in forms

I have to work with LibreOffice Base, and when I created a form to fill the table. It worked perfectly, but when I wanted to use agains it randomly changed the maximum type-able character limit. I ...
0
votes
2answers
42 views

Which query performs better when searching a row where a column has maximum?

Consider a simple table for example purposes: person(name varchar, age int) I have a task to retrieve the oldest person. Which query is better in general for such problems? Query 1: criteria with ...
0
votes
1answer
1k views

What is the query to get the process limit on Oracle 11g?

I'm getting the error: Maximum Number Of Process Exceeded I want to see (using a query) what the setting is in my database for the process limit. My question is: What is the query to get the ...
0
votes
1answer
621 views

Maximum number of fields/columns in MongoDB

I'm considering learning and using MongoDB for a project, but I'm going to need to be able to store at least 1024 columns for the first part, and as many as 1048577 for the second. Does MongoDB have a ...