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Questions tagged [performance]

An evaluation of whether a system works well enough to be fit for purpose. Normally performance refers to the speed with which a system completes an operation or set of operations over time.

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MariaDB Performance Degradation After Brief 20 Hour Massive Improvement

Problem On 2024-05-07 20:00:00 we migrated our DB from MariaDB 10.5 on an 8 core 16GB RAM server with a 10GB innodb buffer pool to a MariaDB 10.11 server with 16 cores 32GB RAM and a 20GB buffer pool ...
Joe Keilty's user avatar
3 votes
1 answer
78 views

PostgreSQL has stopped using index for large IN query?

I've got a large table (~2.2 billion rows), the table structure is basic: Column | Type | Collation | Nullable | Default | Storage | Compression | Stats target | ...
Zak123's user avatar
  • 133
0 votes
1 answer
23 views

How can I monitor query performance on my Azure read-replica database?

I'm looking at Query Performance Insight for my read-replica database. But the information it shows are the performance stats from the primary database. How can I get the performance stats for the ...
Yossi Geretz's user avatar
0 votes
1 answer
17 views

Do the vCores in my Read-Replica process the synchronization activity?

My initial understanding of my read-replica is that it would be less busy than the primary. After all, the primary is processing all the reads, inserts, updates and deletes which are supporting my ...
Yossi Geretz's user avatar
4 votes
2 answers
138 views

Index seeks and predicate push down

I have a query of the following form: IF EXISTS ( SELECT 1 FROM ( SELECT RowID, OETID FROM @InMemoryTableTypeTable i UNION ...
Dan Def's user avatar
  • 163
0 votes
0 answers
54 views

How to tune MS SQL partitioned table with huge data and and low performance [closed]

I have to design a table in MS SQL Server , to store operational data of commercial resellers. I have 300 millions of rows per year and I have to access data of the last of 3 to 5 years (it depends on ...
Radioleao's user avatar
  • 127
0 votes
2 answers
89 views

Performance issue - using try catch to return data to service & how to use partition table with unique index

I'm working on enviorment SQL azure. I've got a stored procedure that runs from several AKS simultaneously and insert a message. So it's a race for who writes the message first and the rest fails. The ...
dexon's user avatar
  • 47
0 votes
0 answers
50 views

High number of Latch Waits, is it a problem, and how to investigate?

We have reports of performance issues on one of our applications. I tried to have a look for anything obvious, but I'm an Oracle DBA, and my SQL Server knowledge is pretty limited - we don't have any ...
Carlovski's user avatar
  • 113
-3 votes
2 answers
94 views

Why is the performance of these two equal queries so different? [closed]

This specific query has an average return time of 3:40 minutes SELECT ROUND((SUM(ENF.TEMPO) / 24 / 60), 2) AS BROCHADEIRA FROM ( SELECT SZ9030.Z9_RECURSO AS COD_REC, ((ISNULL(TEMPO.TEMP, 0) + ...
Gabriel Pereira's user avatar
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0 answers
26 views

I increased my NDF files from 3 files to 7 files. How to re-distribute the data across MDF and NDF files?

I have a big database that uses 1 MDF files and 4 NDF files. The MDF file is placed in a 2TB disk and NDF files are placed in 500GB disks separately. I set the MDF file to be unlimited, while the NDF ...
Affan Widyan's user avatar
0 votes
1 answer
32 views

PostgreSQL & SQLAlchemy: Minimizing Impacts of latency with chatty applications

Are there any ways to minimize the impact of latency between the application and database when running PostgreSQL & SQLAlchemy ORM? Changing loading strategies or preloading properties has been ...
Justin Lowen's user avatar
0 votes
2 answers
50 views

High number of loops in within a nested loop Index Scan

Query SELECT organizations.lf_id, organizations.eb_id FROM organizations JOIN organization_lists_organizations ON organizations.id = organization_lists_organizations.organization_id WHERE ...
andrepcg's user avatar
  • 101
1 vote
1 answer
35 views

How to choose hardware for MYSQL Server in Azure - Flexible Server

I have a MYSQL Flexible Server in Azure with the following hardware configuration: MYSQL 8.0 Compute Tier: Business Critical - 16 vCores Size: E16ds_v4 Storage: 269 GB AutoScale IOPS RAM: 128 GB I ...
SakZepelin's user avatar
1 vote
1 answer
42 views

What does psql do on connect (that could be taking 1 to 10 minutes)?

In some cases psql is taking ~1 to 10 minutes to connect to PostgreSQL, with no queries that it seems to be running while doing so (according to pg_activity that I think queries pg_stat_activity) I'm ...
Michal Charemza's user avatar
0 votes
3 answers
85 views

How to best optimize computer for intensive Mysql queries?

I have a series of tasks I run in MYSQL 8 every day. Actually these tasks are run from a vb.net application that interfaces with MYSQL using 8 connections at a time. These tasks are a series of ...
Luke Krell's user avatar
1 vote
0 answers
24 views

Slow inserts into Azure PostgresSQL database

I have a simple table on what is basically a completely fresh database: create table import_test_uuid ( id integer not null generated by default as identity primary key, guid uuid ); I am ...
mohamedmoussa's user avatar
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0 answers
22 views

Mysql sharding in depth

I have a table that looks like this. Learning sql recently, USERID|MATCHID|TOURNAMENTID|SCORE|COUNTRY There are different tournaments running day to day and each tournament has many matches. some ...
umarkaa's user avatar
  • 37
0 votes
0 answers
25 views

Performance difference in SQL queries using JOINs with function

I have two SQL queries that are structurally the same, but have a significant difference in execution time. The first query takes around 500ms to execute, while the second one takes only 50ms. Both ...
Timon's user avatar
  • 33
0 votes
0 answers
32 views

Performance issue - cant fix with pg_plan_hints

I have a query that is stored in a function. It is called via a prepared statement jdbc app. I have a fix for the query to force an index - but I cant get the "normalized form" required for ...
captaintwocan's user avatar
0 votes
1 answer
53 views

Why adding a where on a well-know set of result increase the process time? [closed]

On SQL Server, if I do this query: select top(10) * from MyTable order by id desc it tooks only some ms to execute. (please note, every rows contains a field Message with value "Some Fancy ...
markzzz's user avatar
  • 243
0 votes
2 answers
62 views

Function performance is worse than raw query in PostgreSQL

I am trying to squeeze out the all the performance from my PostgreSQL database, also I want to abstract my query definitions from my application layer. To do that, I am using table-valued function. ...
vurqac's user avatar
  • 3
2 votes
1 answer
96 views

Can this subquery be optimized by a join? - Even without foreignkeys?

I have a table with two important columns: entity and enabled. The idea is that entities are "unique groups" where all rows with the same entity belong to the same "item". I wish ...
paul23's user avatar
  • 473
0 votes
0 answers
7 views

How to restore a backup and incremental backup of scyllaDB

I am working on incremental backup and restore. When I am trying to restore the incremental backup, after restoration, I am getting an error on cqlsh shell. ReadFailure: Error from server: code=1300 [...
MANJESH H S's user avatar
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0 answers
26 views

Purely in performance terms, how do CONTAINS([MyCol], 'foo') and [MyCol] LIKE '%foo%' compare?

Consider CONTAINS([MyCol], 'foo') and [MyCol] LIKE '%foo%'. Assume the best possible indexes on [MyCol], whatever those may be (at minimum, we need a unique key and a full-text index). I know that the ...
J. Mini's user avatar
  • 431
1 vote
2 answers
90 views

Recommendations to reduce table rows [closed]

I'm looking for some recommendations when dealing with tables with large number of rows. I have a table which has around 1.5 BILLION rows. Assuming there is a column ref_id. There could be 300K rows ...
Emmanuel Ponnudurai's user avatar
0 votes
0 answers
24 views

Deadlock - due to long transaction SQL server

I've got a stored procedure that runs 3 inner procedures all within a one BEGIN TRANSACTION. The environment is : Azure database sql as a result i have many deadlocks for the table : TranStatus. the ...
dexon's user avatar
  • 47
0 votes
1 answer
65 views

Metadata query slow on one specific database

I have quite a weird problem (who doesn't). Our ETL Software scans source databases to claim object data. It extracts information from INFORMATION_SCHEMA about objects (tables and views) SELECT t.[...
LonelyDBA92's user avatar
0 votes
0 answers
91 views

T-SQL Temp Table Performance Issue

At my current contractor job, I have come across something I have never seen before in SQL performance. There is a report that takes most of the day, or the entire day to run. Can return about 5 ...
user avatar
0 votes
1 answer
51 views

Index usage for NULL values

If there is index for a column, will it speed up search if condition is ... WHERE column IS NULL? In fact it is composite index on 2 columns and second column can be NULL (WHERE col1 = X AND col2 IS ...
i486's user avatar
  • 235
0 votes
0 answers
24 views

Temporary shutdown of autovacuum during rush hour

I have been asked to temporarily disable autovacuum in PostgreSQL 14.3. From 7 a.m. to 5 p.m., autovacuum is to be turned off, and at other times it is to be turned back on. I intend to achieve this ...
Patryk's user avatar
  • 1
2 votes
1 answer
134 views

MySql Aurora - how often to run ANALYZE TABLE?

I have a database that has existed for about 10 years, with hundreds of tables, many of which have several million rows. We don't have a DBA and we have an increasing number of slow queries. We're ...
mstrom's user avatar
  • 133
2 votes
1 answer
139 views

SSMS User Mapping Slow to Load, or Not Responding

I have been experiencing an issue in SSMS versions 14, 18, and 19, where loading the User Mapping of any given Login takes an age to load, sometimes up to an hour, or just never loads at all and hits ...
L.Moy's user avatar
  • 45
1 vote
0 answers
41 views

PostgreSQL - Star Schema - Execute plan seems "dumb" and i can't figure out why

I'm using a postgresql (15.5) database with the following logic: We have "meters" who measure electrical consumption. We have "computer meters" who are calculation of the ...
Sébastien De Wolf's user avatar
0 votes
2 answers
38 views

Need help identifying opportunities for improvement in table config and query design

I am working on a project with a fairly large data set. We require arbitrary aggregates on this dataset, these are generated at request time from a user. Here is a basic description of our current ...
Kyle Chamberlin's user avatar
0 votes
0 answers
44 views

Why are my Laravel migrations (MySQL) so much faster in MacOS?

This is not so much of a problem as it's mostly just up to some hundreds of milliseconds of difference per migration; but I could not understand why my desktop [Windows 11] with I7-13700K, 64GB RAM, ...
Rick's user avatar
  • 113
0 votes
0 answers
41 views

Why Reads in Log file are more than writes in SQLServer Database?

In my office environment, there are databases for which reads in log files are more than writes. The above screenshot represents 3x reads in log file compared to write in one of the database. This ...
Ajay Dwivedi's user avatar
0 votes
3 answers
261 views

Why Do Primary Keys on Temp Tables Improve Performance Much More Than On Table Variables?

Many of my reports are essentially pivot tables. I take a set of big tables and transform each table individually so that a particular column (let's call it CaseID) that wasn't a primary key in the ...
J. Mini's user avatar
  • 431
0 votes
0 answers
26 views

Postgres DISK IO very high

I have very little experience in database administration, so I would like to ask you for help. I'm working on a home project that collects product information from one of the marketplaces. I'm ...
Dudoserg's user avatar
0 votes
1 answer
76 views

Techniques for increasing speed of simple select query using DBI R package to MS SQL server where ASYNC_NETWORK_IO is the bottleneck

I am executing a simple select query similar to: DBI::dbGetQuery(db, "SELECT date, x, y, FROM table") where the table contains a large amount of financial data. The db is a MS SQL server ...
nvt's user avatar
  • 1
0 votes
1 answer
44 views

Partition table and partition elimination

I've got a large table of about 300 millones rows. My enviorment is Sql server azure. There are constant insert to this table And some updates. The quieres for this table are only for data in the past ...
dexon's user avatar
  • 47
0 votes
1 answer
43 views

Index for constantly updated rows

I have a cron on my server that runs every minute, it looks for all registered people who did not have their last connection updated in the last 10 minutes and changes the value in a column in the ...
Tom's user avatar
  • 428
1 vote
1 answer
124 views

Postgresql super slow on server - super fast locally?

I am hosting a Postgresql database on Heroku with a standard-0 plan. My database has a table called transactions which contains ~18 million rows: SELECT COUNT(*) FROM transactions; count ---------...
zarathustra's user avatar
2 votes
2 answers
111 views

Is there known such big perfomance diff between current MySQL and MariaDB?

I installed Mysql 8.0.36 on Debian 12 VM (name it VM_A), then created for simple performance testing table your_table and procedure prepare_data (inspired SO answer) like this: CREATE TABLE your_table ...
w.k's user avatar
  • 141
0 votes
2 answers
69 views

Storing terabytes of data in Azure SQL Server

I need to develop a Azure SQL server production system capable of storing a user item recommendations based on the user's purchase history, user health profile and item recommendations(around 415 MB). ...
Ajit Goel's user avatar
  • 103
1 vote
0 answers
31 views

Does aggregation order affect performance

I read on a blog that changing the order of aggregation (using group by 1,2 instead of group by 2,1 can affect the performance of the query. But the costs of both the query plans are identical. Yet, ...
ahron's user avatar
  • 803
0 votes
0 answers
48 views

Designing Tables for Regular Updates in PostgreSQL

I have a PostgreSQL table that contains information about transactions, currently totaling 50 million rows. The table has 16 columns, with 4 of them being indexed. Transactions are frequently inserted,...
Daulet's user avatar
  • 1
0 votes
1 answer
212 views

question about using Insert where not exists instead of if not exists then

I have a procedure that insert data to table where the data doesn't exists. right now it's done in two steps : check if the data exists already, if not, insert it i want to change it to do INSERT ...
dexon's user avatar
  • 47
0 votes
2 answers
85 views

Help with high CPU on Oracle Rac node caused by Oracle processes with *_so and *_ag in the process command name

I have one node in a RAC cluster that is seeing very high CPU and it seems to be caused by several Oracle processes ending with _ag and _so in the process command name. The other node is not seeing ...
jmichaelwDBA's user avatar
2 votes
2 answers
153 views

How to measure the cost of enabling Query Store?

Enabling Query Store can have performance benefits, particularly as of SQL Server 2022, but what about the costs? The documentation insists that the costs are small, but I want proof on my own system. ...
J. Mini's user avatar
  • 431
0 votes
0 answers
37 views

Does high overall avg write latency on core app db data file and temp db data file due to brief period of pressure have any remedy?

My read and write latency throught the day is between 5ms to 20ms, across all drives. There is a heavy process that runs at around 5pm for 30-min during which the write latency for the core ...
variable's user avatar
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