database-performance Questions
3
Solved
Query:
select id, event_time from events where event_time > 1395797406712 and event_time < 1398389406712 order by event_time asc.
this query returns ~25k rows (500KB in total size).
When I...
Aleron asked 25/4, 2014 at 2:9
2
Solved
Is it faster find a node by id function
MATCH (i:Item) WHERE id(i) = 2345 RETURN i
or by a property indexed?
MATCH (i:Item { name: "Foo"}) RETURN i
Profiling these queries I saw
id functio...
Aggravate asked 22/1, 2016 at 9:43
1
I'm working with a relatively large Postgres db containing several terabytes of data. It consists of data from 5 years back. As a result all the indexes are growing and therefore reducing the query...
Olio asked 10/4 at 14:8
2
This is a FastAPI project using SQLAlchemy and an AWS RDS postgres database. The waits (AAS) on database suddenly increase above 2 (for a 2 vCPU - t4g.small instance), and when checking on Performa...
Conjunctive asked 5/10, 2023 at 14:15
3
Solved
I'm working on an application that tracks and handles work orders/tickets. Each ticket is linked to the user who creates/owns the ticket via a foreign key that cascades any changes in MySQL. Obviou...
Tunis asked 21/12, 2011 at 18:18
6
Solved
I'm doing a project that deals with structured document database. I have a tree of categories (~1000 categories, up to ~50 categories on each level), each category contains several thousands (up to...
Percy asked 22/11, 2013 at 17:41
2
Solved
What is the use of sp_updatestats? Can I run that in the production environment for performance improvement?
Mehalek asked 3/5, 2014 at 5:45
4
Solved
After turning on profiling in MySQL
SET profiling=1;
I can run like a query like SELECT NOW(); and see profile results with it's execution time using:
SHOW PROFILES;
However, I can't figure...
Spence asked 20/1, 2014 at 17:5
5
Solved
I started to use dapper.net a while ago for performance reasons and that I really like the named parameters feature compared to just run ExecuteQuery in LINQ To SQL.
It works great for most queries...
Mouthpart asked 28/3, 2013 at 13:29
2
Solved
I'm reading "Dissecting SQL Server Execution Plans" from Grant Fritchey and it's helping me a lot to see why certain queries are slow.
However, I am stumped with this case where a simple rewrite p...
Couplet asked 28/2, 2012 at 14:46
3
Last time I get alert from MongoDB Atlas:
Disk I/O % utilization on Data Partition has gone above 70 on nvme2n1
But I have no any ideas how can I localize / query / index / part of code / probl...
Singultus asked 19/7, 2019 at 21:12
1
Solved
I would like to speed up the queries on my big table that contains lots of old data.
I have a table named post that has the date column created_at. The table has over ~31 million rows and ~30 milli...
Flosser asked 3/6, 2022 at 9:43
3
I know this is a common question and I have read several other posts and papers but I could not find one that takes into account indexed fields and the volume of records that both queries could ret...
Divider asked 4/7, 2013 at 19:51
1
Solved
As a follow-up to this question:
How to "PERFORM" CTE queries in PL/pgSQL?
I try:
perform (with test_as_cte as(select * from myTable) select * from test_as_cte);
But get the following ...
Myrica asked 8/2, 2022 at 21:2
2
Solved
What are the performance implications in postgres of using an array to store values as compared to creating another table to store the values with a has-many relationship?
I have one table that n...
Heartache asked 22/5, 2014 at 15:18
3
I'm using Oracle Database 11.2.
I have a scenario where I issue FLASHBACK DATABASE quite often.
It seems that a FLASHBACK DATABASE cycle does a reboot of the database instance which takes approx. 7...
Cartogram asked 10/6, 2019 at 12:38
5
Solved
oI have a table with 2 millions of registers, but it will grow much more soon. Basically this table contains points of interest of an image with respective descriptors. When I'm trying to execute q...
Mountainside asked 21/3, 2013 at 12:4
4
Solved
I'm trying to establish how much slower Entity Framework is over Stored Procedures. I hope to convince my boss to let us use Entity Framework for ease of development.
Problem is I ran a performanc...
Isa asked 16/3, 2012 at 14:35
5
I have a table CANDIDATE in my db which is running under MySQL 5.5 and I am trying to get rows from table where RAM is contains in firstname, so I can run below two queries, but I would like to kno...
Jahveh asked 20/5, 2013 at 9:43
7
Solved
Using SQL Server Management Studio.
How can I test the performance of a large select (say 600k rows) without the results window impacting my test? All things being equal it doesn't really matter,...
Changsha asked 6/8, 2009 at 16:29
1
Solved
Here's my table schema:
CREATE TABLE tickers (
product_id TEXT NOT NULL,
trade_id INT NOT NULL,
sequence BIGINT NOT NULL,
time TIMESTAMPTZ NOT NULL,
price NUMERIC NOT NULL,
side TEXT NOT NULL...
Crud asked 31/3, 2021 at 21:30
1
Solved
Here's my table schema:
CREATE TABLE tickers (
product_id TEXT NOT NULL,
trade_id INT NOT NULL,
sequence BIGINT NOT NULL,
time TIMESTAMPTZ,
price NUMERIC NOT NULL,
side TEXT NOT NULL,
last_s...
Tilth asked 31/3, 2021 at 19:16
7
Solved
I have a table with more than 100 millions rows in Innodb.
I have to know if there is more than 5000 rows where the foreign key = 1.
I don't need the exact number.
I made some testing :
SELECT ...
Jellaba asked 11/6, 2012 at 7:59
2
Solved
I have cases where I build bulkWrite operations where some documents have the same update object, is there any performance benefit to merging the filters and send one updateMany with those filters ...
Research asked 21/1, 2021 at 16:4
2
Solved
We use uniqueidentifier for every record within a very large database. For business reasons we need to ensure that the uniqueidentifier is never used more than once, but for performance reasons we ...
Kellda asked 13/5, 2016 at 6:31
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