Questions tagged [nosql]
A catch-all term describing database systems using various non-relational models. Such systems are usually engineered to be high-performance.
416
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Millions of events, real time scoring, what are my options?
I'm a junior engineer currently focused on studying the migration of a database away from Cassandra (for several reasons). This database handles the storage of 10 million events daily, originally in ...
0
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1
answer
27
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Possible options for SQL and NoSQL combination for social media data
I have searched this forum for an answer but could not find anything relevant. We are designing database schemas for a social media app with posts, groups, users and chats etc and it looks like we ...
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34
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Does NoSQL databases have a common language like SQL?
I am trying to learn NoSQL databases with a focus on the JSON/key-value type. According to this blog from redis
Column, graph, key-value, in-memory, and document are all different
types of NoSQL ...
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Why use $group / group_by instead of multiple requests?
Let's suppose that there are 100 types of dogs scattered across the documents of my collection. If I need to group by types of dogs and then compute some aggregate statistic about each type of dog, ...
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31
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Cassandra compact executor exception
When I try to load the SStable in through sstableloader, I am getting this following error:
ERROR [CompactionExecutor:28] 2023-09-26 10:48:37,680 JVMStabilityInspector.java:68 - Exception in thread ...
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22
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SSTable loading concurrent exception
While loading sstables through SSTableLoader command, I am frequently facing this issue.
java.util.concurrent.ExecutionException: org.apache.cassandra.streaming.StreamException: Stream failed
...
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0
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22
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MongoDB set field in array of embedded documents to value of another field
Within my document I have an array of embedded documents. I want to set the value of one field from one of the documents in the array to the value of another field, outside the array but in the same ...
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65
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How to index when the fields used in the query is unpredictable?
In collection A, each document contains up to 100 fields. The database, mongoDB, only allows up to 64 indexes on a single collection.
Indexes are needed for a query on this collection. The filter, or $...
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1
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29
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Solution to query that must examine all rows / documents in worst case
The logic of my query goes like this:
Filter documents based on arbitrarily many and non-predetermined fields. The filter conditions can total to hundreds. But the worst case is that there are no ...
0
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2
answers
20
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Suitable database for json type data
I am trying to find out which database will be more suitable to store JSON type data in my case.
Let's say I have this data at some point:
[
{
"parent_name": "A",
"...
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36
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mongod binary path is not obtained by "db.serverStatus().process" on Ubuntu 20.04
I am unable to get mongod binary path using "db.serverStatus().process" on Ubuntu 20.04.
I need to incorporate this command in a script. But "db.serverStatus().process" gives just '...
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How can I make (game_id, user_id) unique, yet (game_id, score) indexed/clustered, in ScyllaDB?
See this in ScyllaDB:
CREATE TABLE scores_leaderboards (
game_id int,
score int,
user_id bigint,
PRIMARY KEY (game_id, score, user_id)
) WITH CLUSTERING ORDER BY (score DESC);
The ...
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98
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What makes many NoSQL databases non-ACID compliant when both SQL and NoSQL can scale horizontally
A lot of the difference between SQL and NoSQL that is talked about focuses on the fact that SQL support ACID properties while in many NoSQL dbs ACID is compromised.
I'm unsure of the reason but ...
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90
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NoSQL vs SQL during sharding when a single read operation only hits one shard
I've a use case where I'm stuck between figuring out whether to use SQL or NoSQL db.
The db has 2 fields - A (PK), B
A is 8 char-long, while B is 100-400 char long.
The operations are simply:
Write: ...
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2
answers
464
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How can I prevent race conditions in Cassandra?
Lets say two users simultaneously want to access the same partition of a Cassandra table:
Suppose we have a Cassandra table called "user_data" that stores user data. The table has a ...
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51
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Is this a reasonable setup for a Firebase backend for a group chat app?
This is my idea so far:
Firestore will store group info that will never/rarely change, such as groupID, groupName, groupAdmin:
Lock down Firestore such that a user can only read from a collection ...
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1
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737
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How to get current date and time in Elasticsearch
I need to review the current date and time zone from Elasticsearch. I'm checking the elastic documentation and it mentioned that the default value is UTC.
In other environments I use:
SELECT NOW();
...
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0
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90
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Disk based Key-Value store to use as LRU cache?
I am looking for a key value store to use as a LRU cache for my application. It needs to hold a lot of data (100G - 1000G) which is why I say disk based. Things I have found via Google seem to be ...
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1
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1
answer
41
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Best way to create a relationship in a mongodb database?
I have a database that is similar to the following:
We have 'projects' and projects will consist of multiple 'steps' each step has multiple 'todos'.
The first schema that comes to mind is something ...
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281
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Mongoexport query using date range on Linux
I'm trying to run mongoexport using this query:
mongoexport --db=database --username=user --password=pass --collection=coll --type=csv --fields=Name --query='{ "Date" : { "$gte" : {...
Fernanda Andretto
3
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0
answers
37
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Data modelling for dynamic grouping of rows in Cassandra
I have a feed of game events with a schema like;
{
"gameId": text,
"playerId": text,
"eventId": text,
"ts": bigint,
"metrics": map<...
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1
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28
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Database recommendation storing a growing set of recordings
Suppose I have a large volume of recordings coming in from various sources. Encoded as JSON-lines, they might look like this:
{ "metric": "temperatureRange", "values": [ &...
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1
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1k
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What difference between columnar and wide column databases?
What difference between columnar database (AWS Redshift, Azure Synapse, GCP Bigquery, Snowflake) and wide column database (AWS Keyspaces, Azure CosmosDB, GCP Bigtable, Hbase, Cassandra)?
What I ...
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1
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214
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Product Object for Ecommerce in NoSQL
I'm working on an ecommerce app that will be using a NoSQL document database. I want to have a general purpose product that can be used for different types of products, ranging from coffee to ...
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1
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230
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How do I model a Cassandra table that stores friends of a user?
Recently I started to learn Cassandra. I needed to design the database for my web application. So, I prepared conceptual data model as well as application workflow, and currently I’m stuck on ...
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2
answers
531
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Should I store compressed JSON in a CQL blob type or multiple Cassandra columns?
Purpose of the table is to maintain Audits.
Expected Behaviour: Huge writes with infrequent reads and no edits.
Table Definition:
PartitionKey(multiple columns), ClusteringKey(time-uuid), json BLOB;
...
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0
votes
1
answer
74
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How to evaluate Database benchmarks ? What to consider given a specific example?
I'm trying to figure out which database to use for a project which is supposed to implement a temporal property graph model and I am looking into some benchmarks for that. I found some papers which ...
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1
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157
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The most efficient way to query a growing collection/table
I'm asking this question for both SQL and NoSQL implementation as the principle is the same and I'm curious to hear peoples' thoughts (I'm a beginner who is curious about both, particularly MongoDB &...
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153
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Cannot run nodetool commands after enabling JMX authentication in DSE
I would like to use these two pages to enable DSE Unified Authentication and realize a secure environment.
I have tried to configure it but it does not work.
How is it as a symptom.
When I type ...
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1
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282
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cassandra-stress returns "Failed to connect over JMX; not collecting these stats"
I took the DS210 course offered by Datastax and prepared a cluster of almost the same configuration by myself. I edited the /etc/dse/cassandra/cassandra-env.sh file in Exercise 2.3, but I still got &...
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1
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268
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If Cassandra is so good for write, why read isn't encouraged?
Background for this question
I have a machine learning pipeline where all our Features and pre-calculated prediction scores are stored in PostgreSQL database.
I have in excess of 800 columns as ...
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68
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Schema design for tracking the gaz prices in MongoDB
I would like to build an app that give the ability to
search for the cheapest gaz price around
Display the gaz price trend whether it's up or down.(similar to the stock price)
The data source are ...
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2
votes
1
answer
610
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How do I get a Cassandra node to show the IPv4 address in the nodetool status output?
I'm currently working on a cluster with DataStax Enterprise 6.8, but the address part of the picture is showing up as localhost (127.0.0.1).
How can I get it to show the actual IPv4 address?
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NoSQL DB candidate for the project (looking for experienced advice)
Intro
I am stuck with the limitations of the DBs I've tested* and need someone experienced to give me some advice.
Project details
Data sets
The project has 2 sets of data, the sets of items and their ...
1
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1
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819
views
How to update mongodb configure at Docker?
I am unable to enable security parameter at docker of mongodb at mongod.conf file. So how can I configure any parameter at mongod.conf file?
I found a file inside mongodb container named it as mongod....
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1
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281
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Repetition of Data in NoSQL Document Database
This is a very "noobish" question, but I'm working on a project with a document database and I think they are using it wrongly. Thus, I kinda want to confirm this, as I feel it is tainting ...
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1
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1k
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How do we handle ALTER TABLE column TYPE in Cassandra in actual scenarios?
I'm aware of the restrictions Cassandra has on modifying column data types once table is created or even dropping and adding column with same name of different data type.
Dropping and Adding is ...
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How do I migrate a Northwind DB to Cassandra? [closed]
I want to migrate data from a Northwind database to Apache Cassandra.
How would I go about modelling the data for NoSQL? What are the recommended techniques and/or methodologies to accomplish this?
I ...
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3
answers
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Why is it more difficult to horizontally scale a relational database than a NoSQL database like MongoDB?
Is the main reason for the difficulty in horizontally scaling / distributing an RDBMS because of an adherence to ACID transactions? Is it the fact that multiple tables are so interconnected, or ...
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1
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What kind of database to store Quotes
I'm designing a very simple application to send positive text messages to subscribers at a certain frequency.
These are just famous, motivational, encouraging and positive quotes.
When I first thought ...
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Does it make sense to use a non-relational database for reporting/BI/visualisation tools?
Relational databases are well used in reporting/visualisation tools such as Power BI, Tableau...
Non-relational databases are getting popular and many reporting tools allow its connection. However I ...
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164
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Better way to store panel data in SQL or NoSQL
I have an Excel of raw panel data (cross sectional + time series) sent to me by customers (I cannot change this). For those not familiar, imagine the gdp time series for each country. I need to ...
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720
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Attempting to remove Object from a Array where an attribute matches the value passed through the query [closed]
I am attempting to write a query that removes the element from the array based on the messageId associated with said object in the array. This is submitted through curl hence the formatting, I've ...
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2
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Is SqlServer or NoSql more cost efficient when scaling horizontally
RDBMS are traditionally better for vertical scaling since it's harder to do horizontal scaling. As a result NoSql databases are cheaper since they can more easily scale horizontally.
However in recent ...
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2
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4k
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Create an index for fields within an array of composite type
My question is a follow-up to the question answered here:
https://stackoverflow.com/a/15041094/994263
Considering a table with an array column of a composite type, is it possible with PostgreSQL to ...
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3
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349
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SQL or/with Nosql
I am designing a mobile app with basic functionality such as sign-up, Auth, posts, real time messages etc. I think for this kind of work Nosql should work better. But over a long period of time I want ...
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485
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Should I use SQL vs NoSQL for files catalog? [closed]
I will be implementing a system which will be storing 250 Million files/user. I want to perform list operations from the client side, where the client application will be fetching 100 records at a ...
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555
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Joining in NoSQL to get chat messages for a user
In my chat app i have private / group chats and I need to get messages for a user.
Let me first explain the whole system.
Messages:
// group message
{
id: 1,
text: 'hello',
chat_id: 'AjK954_e5iP'...
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57
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Transactional Inserts and updates in NoSQL
Let's say I'm using Database X which is NoSQL and doesn't support transactions.
1. Update A
[error] server goes down
2. Insert B
In a scenario, A is updated and suddenly our server goes down or the ...
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668
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How to store and query a tree structure in Cosmos DB?
I'm migrating a relational DB over to Cosmos DB and am unsure about a tree structure.
There are several thousand rows of data ("Offerings") where each offering can have child items arranged ...
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