database-performance Questions
1
I've been doing some load testing of AWS Redshift for a new application, and I noticed that it has a column limit of 1600 per table. Worse, queries slow down as the number of columns increases in a...
Tother asked 3/9, 2015 at 15:24
1
Solved
Is there a limit on the number of labels you can put on nodes in Neo4j?
Also what are the ramifications of lots of labels on the performance of inserts?
Thanks
Acrefoot asked 30/8, 2015 at 19:40
2
Solved
The documentation for sys.dm_db_missing_index_group_stats uses the terms "user queries" and "system queries" but it doesn't define what those mean. For example:
user_seeks: "Number of seeks cause...
Rhizotomy asked 12/8, 2015 at 23:56
2
We're using MySql 5.5 in our production environment. Is it advisable to turn on slow query logs in production? What is the performance implication of doing so? I referred official doc here, but it ...
Diagonal asked 8/8, 2015 at 13:41
3
Solved
Objective
Verify if it is true that insert records without PK/index plus create thme later is faster than insert with PK/Index.
Note
The point here is not about indexing takes more time (it is o...
Karakorum asked 2/7, 2015 at 3:12
3
I have 4 nodes HBase v0.90.4-cdh3u3 cluster deployed on Amazon XLarge instances (16Gb RAM, 4 cores CPU) with 8Gb heap -Xmx allocated for HRegion servers, 2Gb for datanodes. HMaster\ZK\Namenode is o...
Marketplace asked 6/4, 2012 at 7:33
2
Solved
I have this process that has to make a series of queries, using pl/pgsql:
--process:
SELECT function1();
SELECT function2();
SELECT function3();
SELECT function4();
To be able to execute everyth...
Bicapsular asked 20/5, 2015 at 13:33
1
Solved
I've researched on what I can about SQLite and UnQLite but there are still a few things that haven't quite been answered yet. UnQLite appears to have been released within the past few years which w...
Kookaburra asked 16/4, 2015 at 0:56
1
Is it possible to alter an existing non clustered index to include more columns as a part of Covered columns.
e.g.
ALTER INDEX IX_NC_TableName_ColumnName
FOR TableName(ColumnName)
INCLUDE(Col1, ...
Ronn asked 29/4, 2015 at 11:45
1
We have a very big database WriteDB, which store raw trading data and we use this table to fast writes. Then with sql scripts I import data from WriteDB into ReadDB in comparatively the same table,...
Staw asked 21/4, 2015 at 12:23
1
We have been using symmetric keys for encryption/decryption on some SQL Server 2012 instances for a few years. We recently installed some new instances of SQL Server 2014 and came across some perfo...
Unbutton asked 17/3, 2015 at 17:3
0
I've got a very simple test program that performs faster with ACKNOWLEDGED bulk inserts than with UNACKNOWLEDGED. And it's not just a little faster - I'm seeing a factor of nearly 100!
My understa...
Danie asked 14/3, 2015 at 2:14
4
Solved
So I'm using mongodb and I'm unsure if I've got the correct / best database collection design for what I'm trying to do.
There can be many items, and a user can create new groups with these items ...
Forbidden asked 9/2, 2015 at 23:32
1
Solved
Python 2.7.9 Django 1.7 MySQL 5.6
I would like to populate a whole bunch of object instances belonging to multiple classes, stack them up into a single create()-like query, open a database connect...
Valladolid asked 30/12, 2014 at 19:55
3
I wish to fetch the last 10 rows from the table of 1 M rows.
CREATE TABLE `test` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`updated_date` datetime NOT NULL,
PRIMARY KEY (`id`)
)
One way of doin...
Eal asked 30/12, 2014 at 11:50
4
If the following database (postgres) queries are executed, the second call is much faster.
I guess the first query is slow since the operating system (linux) needs to get the data from disk. The s...
Myelencephalon asked 25/11, 2014 at 14:22
2
Solved
Background
I noticed whilst experimenting with running total queries that sometimes the estimated plan just shows a "Fetch Query"
and the actual plan shows repeated Fetches from the Clus...
Nielson asked 23/10, 2011 at 21:1
4
Solved
This is very similar to another question that got closed as not a real question. I tried to edit it to make it valid for reopening but was told I would be better off asking a new question.
I'm deve...
Freeboard asked 17/11, 2014 at 17:27
1
Solved
I've just made a quick search through the web but couldn't find exactly what I'm looking for.
How much efficient an INNER JOIN is comparing to a regular WHERE statement?
I have a couple of querie...
Anthropocentric asked 12/11, 2014 at 12:26
2
Consider the following table :
foo | bar
-----+-----
3 | 1
8 | 1
2 | 1
8 | 5
6 | 5
5 | 5
4 | 5
5 | 7
4 | 7
Column foo contains whatever. Column bar is almost ordered and rows of common...
Brand asked 30/9, 2014 at 17:31
2
Solved
In an InnoDB database a field to store domain names that will be indexed and 64 chars long, can be either of datatype CHAR(64) or VARCHAR(64), where the first would pad the data so all record...
Torch asked 25/10, 2014 at 0:24
8
Solved
In our product we have a generic search engine, and trying to optimze the search performance. A lot of the tables used in the queries allow null values. Should we redesign our table to disallow nul...
Mildew asked 19/6, 2009 at 10:5
3
Solved
I need to insert some objects (about 4 million) in the database using C# and EF (using .NET 3.5). My method that adds the objects is in a for:
private DBModelContainer AddToContext(DBModelContain...
Hewe asked 8/10, 2014 at 7:50
1
Solved
Can any one please explain me that whats the better option for an enterprise java web application of more than 500 database tables.Either we should use Grails or Go for (Spring,hibernate and ...
Podolsk asked 27/9, 2014 at 9:32
1
Solved
I really like MongoDB, I use it at work and home, and not once yet have I hit a performance, complexity, or limitation issue with it. But I've been thinking about indexes a lot and I had a question...
Eam asked 18/9, 2014 at 19:26
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